XJ engine instantly revs out at start up
10-07-2007, 05:12 PM
#51
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
"bllsht" <nospam@dot.net> wrote in message
news:haeig39i876dc6o7jd4cj28ipa92iusfh0@4ax.com...
> On Sun, 07 Oct 2007 18:01:52 GMT, "Jeff Strickland"
> <crwlr@verizon.net> wrote:
>
>>I think he does not know. I'm working on the idea that he tried to move it
>>by hand and it would not move, not that he looked inside and discovered it
>>was closed.
>>
>>And, I played with the intake on my Dad's Ranger yesterday and unplugged
>>hoses while it was idling. Without additional gas to go along with the
>>extra
>>air, the fuel mixture became lean, and the engine ultimately died.
>
> Apples and oranges. Trying to prove your "theory" about a Jeep by
> experimenting on a Ford really doesn't make much sense. The Ford
> (assuming fairly late model and fuel injected) has a mass airflow
> system and the Jeep has a speed density system. Two different ways of
> calculating how much air is coming into the engine. The mass airflow
> system gets lean. The speed density system adds fuel to go with the
> additional air.
>
Really!? It can add enough fuel to blow up the motor when it should be at
idle? That would make a very dangerous condition on the trail. Lose a vac
line while rock crawling and immediately suffer full throttle operation in
Low Range. That could be a serious problem, don't you think? I'm not sure my
CJ's brakes can stop in full throttle and low range, 1st or 2nd gear.
Put an inexperienced driver in a situation where a vac leak might come about
and the engine goes to full throttle operation as a result, and there can
easily be lives in the balance.
I'm pretty sure that while there might be a slight increase in idle speed, I
would not expect a condition where one would be concerned with blowing an
engine at what is expected to be an idling situation.
>>
>>You may be right, I'm not arguing your point. All I'm saying is that if
>>the
>>throttle won't move and there is full throttle operation as soon as the
>>engine starts, I suspect the throttle is held full open, not full close.
>>This would give lots of gas and air, any other condition would give lots
>>of
>>air but not much gas.
>
> The OP just removed the intake and replaced the exhaust manifold.
> While he's probably nowhere near as smart as you, I'd bet he can look
> at the throttle plate and know if it was open or closed...
>
You're right, I completely clueless -- except for the part where I converted
my Jeep from the crappy BBD carburator to full Multi Port Fuel Injection. I
have no idea.
The OP is not clear that he looked, or simply noticed that the linkage would
not move by hand.
Murphy's Law states that the simplist thing to fix is the most likely
problem. Assuming that is true, all I'm saying is that the linkage needs to
be checked to be sure the throttle is not already full open when it is
expected to be full closed.
10-07-2007, 05:12 PM
#52
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
"bllsht" <nospam@dot.net> wrote in message
news:haeig39i876dc6o7jd4cj28ipa92iusfh0@4ax.com...
> On Sun, 07 Oct 2007 18:01:52 GMT, "Jeff Strickland"
> <crwlr@verizon.net> wrote:
>
>>I think he does not know. I'm working on the idea that he tried to move it
>>by hand and it would not move, not that he looked inside and discovered it
>>was closed.
>>
>>And, I played with the intake on my Dad's Ranger yesterday and unplugged
>>hoses while it was idling. Without additional gas to go along with the
>>extra
>>air, the fuel mixture became lean, and the engine ultimately died.
>
> Apples and oranges. Trying to prove your "theory" about a Jeep by
> experimenting on a Ford really doesn't make much sense. The Ford
> (assuming fairly late model and fuel injected) has a mass airflow
> system and the Jeep has a speed density system. Two different ways of
> calculating how much air is coming into the engine. The mass airflow
> system gets lean. The speed density system adds fuel to go with the
> additional air.
>
Really!? It can add enough fuel to blow up the motor when it should be at
idle? That would make a very dangerous condition on the trail. Lose a vac
line while rock crawling and immediately suffer full throttle operation in
Low Range. That could be a serious problem, don't you think? I'm not sure my
CJ's brakes can stop in full throttle and low range, 1st or 2nd gear.
Put an inexperienced driver in a situation where a vac leak might come about
and the engine goes to full throttle operation as a result, and there can
easily be lives in the balance.
I'm pretty sure that while there might be a slight increase in idle speed, I
would not expect a condition where one would be concerned with blowing an
engine at what is expected to be an idling situation.
>>
>>You may be right, I'm not arguing your point. All I'm saying is that if
>>the
>>throttle won't move and there is full throttle operation as soon as the
>>engine starts, I suspect the throttle is held full open, not full close.
>>This would give lots of gas and air, any other condition would give lots
>>of
>>air but not much gas.
>
> The OP just removed the intake and replaced the exhaust manifold.
> While he's probably nowhere near as smart as you, I'd bet he can look
> at the throttle plate and know if it was open or closed...
>
You're right, I completely clueless -- except for the part where I converted
my Jeep from the crappy BBD carburator to full Multi Port Fuel Injection. I
have no idea.
The OP is not clear that he looked, or simply noticed that the linkage would
not move by hand.
Murphy's Law states that the simplist thing to fix is the most likely
problem. Assuming that is true, all I'm saying is that the linkage needs to
be checked to be sure the throttle is not already full open when it is
expected to be full closed.
10-07-2007, 05:12 PM
#53
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
"bllsht" <nospam@dot.net> wrote in message
news:haeig39i876dc6o7jd4cj28ipa92iusfh0@4ax.com...
> On Sun, 07 Oct 2007 18:01:52 GMT, "Jeff Strickland"
> <crwlr@verizon.net> wrote:
>
>>I think he does not know. I'm working on the idea that he tried to move it
>>by hand and it would not move, not that he looked inside and discovered it
>>was closed.
>>
>>And, I played with the intake on my Dad's Ranger yesterday and unplugged
>>hoses while it was idling. Without additional gas to go along with the
>>extra
>>air, the fuel mixture became lean, and the engine ultimately died.
>
> Apples and oranges. Trying to prove your "theory" about a Jeep by
> experimenting on a Ford really doesn't make much sense. The Ford
> (assuming fairly late model and fuel injected) has a mass airflow
> system and the Jeep has a speed density system. Two different ways of
> calculating how much air is coming into the engine. The mass airflow
> system gets lean. The speed density system adds fuel to go with the
> additional air.
>
Really!? It can add enough fuel to blow up the motor when it should be at
idle? That would make a very dangerous condition on the trail. Lose a vac
line while rock crawling and immediately suffer full throttle operation in
Low Range. That could be a serious problem, don't you think? I'm not sure my
CJ's brakes can stop in full throttle and low range, 1st or 2nd gear.
Put an inexperienced driver in a situation where a vac leak might come about
and the engine goes to full throttle operation as a result, and there can
easily be lives in the balance.
I'm pretty sure that while there might be a slight increase in idle speed, I
would not expect a condition where one would be concerned with blowing an
engine at what is expected to be an idling situation.
>>
>>You may be right, I'm not arguing your point. All I'm saying is that if
>>the
>>throttle won't move and there is full throttle operation as soon as the
>>engine starts, I suspect the throttle is held full open, not full close.
>>This would give lots of gas and air, any other condition would give lots
>>of
>>air but not much gas.
>
> The OP just removed the intake and replaced the exhaust manifold.
> While he's probably nowhere near as smart as you, I'd bet he can look
> at the throttle plate and know if it was open or closed...
>
You're right, I completely clueless -- except for the part where I converted
my Jeep from the crappy BBD carburator to full Multi Port Fuel Injection. I
have no idea.
The OP is not clear that he looked, or simply noticed that the linkage would
not move by hand.
Murphy's Law states that the simplist thing to fix is the most likely
problem. Assuming that is true, all I'm saying is that the linkage needs to
be checked to be sure the throttle is not already full open when it is
expected to be full closed.
10-07-2007, 07:20 PM
#54
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
On Sun, 07 Oct 2007 21:12:09 GMT, "Jeff Strickland"
<crwlr@verizon.net> wrote:
>
>"bllsht" <nospam@dot.net> wrote in message
>news:haeig39i876dc6o7jd4cj28ipa92iusfh0@4ax.com.. .
>> On Sun, 07 Oct 2007 18:01:52 GMT, "Jeff Strickland"
>> <crwlr@verizon.net> wrote:
>>
>>>I think he does not know. I'm working on the idea that he tried to move it
>>>by hand and it would not move, not that he looked inside and discovered it
>>>was closed.
>>>
>>>And, I played with the intake on my Dad's Ranger yesterday and unplugged
>>>hoses while it was idling. Without additional gas to go along with the
>>>extra
>>>air, the fuel mixture became lean, and the engine ultimately died.
>>
>> Apples and oranges. Trying to prove your "theory" about a Jeep by
>> experimenting on a Ford really doesn't make much sense. The Ford
>> (assuming fairly late model and fuel injected) has a mass airflow
>> system and the Jeep has a speed density system. Two different ways of
>> calculating how much air is coming into the engine. The mass airflow
>> system gets lean. The speed density system adds fuel to go with the
>> additional air.
>>
>
>Really!? It can add enough fuel to blow up the motor when it should be at
>idle? That would make a very dangerous condition on the trail. Lose a vac
>line while rock crawling and immediately suffer full throttle operation in
>Low Range. That could be a serious problem, don't you think? I'm not sure my
>CJ's brakes can stop in full throttle and low range, 1st or 2nd gear.
Slow down a litlle, Einstein...
First, in order to "suffer full throttle operation", the vacuum leak
would have to be the size of the throttle body opening at WOT. Do you
see any "vac lines" of that size on your CJ? Nope! It ain't gonna
happen unexptectedly on the trail my friend.
It happens when somebody takes the intake off and doesn't get it back
on right.
As for if it can really happen... Why don't you ask the OP? Hint:
the system has no problem delivering enough fuel with the throttle
wide open. It will do the same with a massive air leak.
On later model Chrysler vehicles with plastic intakes, the PCM is
programmed to prevent this behavior in case the intake were to develop
a large crack. Havent seen an aluminum intake on a Jeep do that.
>
>Put an inexperienced driver in a situation where a vac leak might come about
>and the engine goes to full throttle operation as a result, and there can
>easily be lives in the balance.
There you go thinking too much again.
>
>I'm pretty sure that while there might be a slight increase in idle speed, I
>would not expect a condition where one would be concerned with blowing an
>engine at what is expected to be an idling situation.
It all depends on the size of the leak.
>
>
>
>>>
>>>You may be right, I'm not arguing your point. All I'm saying is that if
>>>the
>>>throttle won't move and there is full throttle operation as soon as the
>>>engine starts, I suspect the throttle is held full open, not full close.
>>>This would give lots of gas and air, any other condition would give lots
>>>of
>>>air but not much gas.
>>
>> The OP just removed the intake and replaced the exhaust manifold.
>> While he's probably nowhere near as smart as you, I'd bet he can look
>> at the throttle plate and know if it was open or closed...
>>
>
>You're right, I completely clueless -- except for the part where I converted
>my Jeep from the crappy BBD carburator to full Multi Port Fuel Injection. I
>have no idea.
You just proved that taking some parts off, and putting some others
back on doesn't require a clue as to how the system works.
Congratulations!
Since your CJ is now equipped with a speed density injection system,
with it idling, go yank a vacuum hose off and report back here what
happens.
>
>The OP is not clear that he looked, or simply noticed that the linkage would
>not move by hand.
>
>Murphy's Law states that the simplist thing to fix is the most likely
>problem. Assuming that is true, all I'm saying is that the linkage needs to
>be checked to be sure the throttle is not already full open when it is
>expected to be full closed.
>
>
>
>
>
<crwlr@verizon.net> wrote:
>
>"bllsht" <nospam@dot.net> wrote in message
>news:haeig39i876dc6o7jd4cj28ipa92iusfh0@4ax.com.. .
>> On Sun, 07 Oct 2007 18:01:52 GMT, "Jeff Strickland"
>> <crwlr@verizon.net> wrote:
>>
>>>I think he does not know. I'm working on the idea that he tried to move it
>>>by hand and it would not move, not that he looked inside and discovered it
>>>was closed.
>>>
>>>And, I played with the intake on my Dad's Ranger yesterday and unplugged
>>>hoses while it was idling. Without additional gas to go along with the
>>>extra
>>>air, the fuel mixture became lean, and the engine ultimately died.
>>
>> Apples and oranges. Trying to prove your "theory" about a Jeep by
>> experimenting on a Ford really doesn't make much sense. The Ford
>> (assuming fairly late model and fuel injected) has a mass airflow
>> system and the Jeep has a speed density system. Two different ways of
>> calculating how much air is coming into the engine. The mass airflow
>> system gets lean. The speed density system adds fuel to go with the
>> additional air.
>>
>
>Really!? It can add enough fuel to blow up the motor when it should be at
>idle? That would make a very dangerous condition on the trail. Lose a vac
>line while rock crawling and immediately suffer full throttle operation in
>Low Range. That could be a serious problem, don't you think? I'm not sure my
>CJ's brakes can stop in full throttle and low range, 1st or 2nd gear.
Slow down a litlle, Einstein...
First, in order to "suffer full throttle operation", the vacuum leak
would have to be the size of the throttle body opening at WOT. Do you
see any "vac lines" of that size on your CJ? Nope! It ain't gonna
happen unexptectedly on the trail my friend.
It happens when somebody takes the intake off and doesn't get it back
on right.
As for if it can really happen... Why don't you ask the OP? Hint:
the system has no problem delivering enough fuel with the throttle
wide open. It will do the same with a massive air leak.
On later model Chrysler vehicles with plastic intakes, the PCM is
programmed to prevent this behavior in case the intake were to develop
a large crack. Havent seen an aluminum intake on a Jeep do that.
>
>Put an inexperienced driver in a situation where a vac leak might come about
>and the engine goes to full throttle operation as a result, and there can
>easily be lives in the balance.
There you go thinking too much again.
>
>I'm pretty sure that while there might be a slight increase in idle speed, I
>would not expect a condition where one would be concerned with blowing an
>engine at what is expected to be an idling situation.
It all depends on the size of the leak.
>
>
>
>>>
>>>You may be right, I'm not arguing your point. All I'm saying is that if
>>>the
>>>throttle won't move and there is full throttle operation as soon as the
>>>engine starts, I suspect the throttle is held full open, not full close.
>>>This would give lots of gas and air, any other condition would give lots
>>>of
>>>air but not much gas.
>>
>> The OP just removed the intake and replaced the exhaust manifold.
>> While he's probably nowhere near as smart as you, I'd bet he can look
>> at the throttle plate and know if it was open or closed...
>>
>
>You're right, I completely clueless -- except for the part where I converted
>my Jeep from the crappy BBD carburator to full Multi Port Fuel Injection. I
>have no idea.
You just proved that taking some parts off, and putting some others
back on doesn't require a clue as to how the system works.
Congratulations!
Since your CJ is now equipped with a speed density injection system,
with it idling, go yank a vacuum hose off and report back here what
happens.
>
>The OP is not clear that he looked, or simply noticed that the linkage would
>not move by hand.
>
>Murphy's Law states that the simplist thing to fix is the most likely
>problem. Assuming that is true, all I'm saying is that the linkage needs to
>be checked to be sure the throttle is not already full open when it is
>expected to be full closed.
>
>
>
>
>
10-07-2007, 07:20 PM
#55
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
On Sun, 07 Oct 2007 21:12:09 GMT, "Jeff Strickland"
<crwlr@verizon.net> wrote:
>
>"bllsht" <nospam@dot.net> wrote in message
>news:haeig39i876dc6o7jd4cj28ipa92iusfh0@4ax.com.. .
>> On Sun, 07 Oct 2007 18:01:52 GMT, "Jeff Strickland"
>> <crwlr@verizon.net> wrote:
>>
>>>I think he does not know. I'm working on the idea that he tried to move it
>>>by hand and it would not move, not that he looked inside and discovered it
>>>was closed.
>>>
>>>And, I played with the intake on my Dad's Ranger yesterday and unplugged
>>>hoses while it was idling. Without additional gas to go along with the
>>>extra
>>>air, the fuel mixture became lean, and the engine ultimately died.
>>
>> Apples and oranges. Trying to prove your "theory" about a Jeep by
>> experimenting on a Ford really doesn't make much sense. The Ford
>> (assuming fairly late model and fuel injected) has a mass airflow
>> system and the Jeep has a speed density system. Two different ways of
>> calculating how much air is coming into the engine. The mass airflow
>> system gets lean. The speed density system adds fuel to go with the
>> additional air.
>>
>
>Really!? It can add enough fuel to blow up the motor when it should be at
>idle? That would make a very dangerous condition on the trail. Lose a vac
>line while rock crawling and immediately suffer full throttle operation in
>Low Range. That could be a serious problem, don't you think? I'm not sure my
>CJ's brakes can stop in full throttle and low range, 1st or 2nd gear.
Slow down a litlle, Einstein...
First, in order to "suffer full throttle operation", the vacuum leak
would have to be the size of the throttle body opening at WOT. Do you
see any "vac lines" of that size on your CJ? Nope! It ain't gonna
happen unexptectedly on the trail my friend.
It happens when somebody takes the intake off and doesn't get it back
on right.
As for if it can really happen... Why don't you ask the OP? Hint:
the system has no problem delivering enough fuel with the throttle
wide open. It will do the same with a massive air leak.
On later model Chrysler vehicles with plastic intakes, the PCM is
programmed to prevent this behavior in case the intake were to develop
a large crack. Havent seen an aluminum intake on a Jeep do that.
>
>Put an inexperienced driver in a situation where a vac leak might come about
>and the engine goes to full throttle operation as a result, and there can
>easily be lives in the balance.
There you go thinking too much again.
>
>I'm pretty sure that while there might be a slight increase in idle speed, I
>would not expect a condition where one would be concerned with blowing an
>engine at what is expected to be an idling situation.
It all depends on the size of the leak.
>
>
>
>>>
>>>You may be right, I'm not arguing your point. All I'm saying is that if
>>>the
>>>throttle won't move and there is full throttle operation as soon as the
>>>engine starts, I suspect the throttle is held full open, not full close.
>>>This would give lots of gas and air, any other condition would give lots
>>>of
>>>air but not much gas.
>>
>> The OP just removed the intake and replaced the exhaust manifold.
>> While he's probably nowhere near as smart as you, I'd bet he can look
>> at the throttle plate and know if it was open or closed...
>>
>
>You're right, I completely clueless -- except for the part where I converted
>my Jeep from the crappy BBD carburator to full Multi Port Fuel Injection. I
>have no idea.
You just proved that taking some parts off, and putting some others
back on doesn't require a clue as to how the system works.
Congratulations!
Since your CJ is now equipped with a speed density injection system,
with it idling, go yank a vacuum hose off and report back here what
happens.
>
>The OP is not clear that he looked, or simply noticed that the linkage would
>not move by hand.
>
>Murphy's Law states that the simplist thing to fix is the most likely
>problem. Assuming that is true, all I'm saying is that the linkage needs to
>be checked to be sure the throttle is not already full open when it is
>expected to be full closed.
>
>
>
>
>
<crwlr@verizon.net> wrote:
>
>"bllsht" <nospam@dot.net> wrote in message
>news:haeig39i876dc6o7jd4cj28ipa92iusfh0@4ax.com.. .
>> On Sun, 07 Oct 2007 18:01:52 GMT, "Jeff Strickland"
>> <crwlr@verizon.net> wrote:
>>
>>>I think he does not know. I'm working on the idea that he tried to move it
>>>by hand and it would not move, not that he looked inside and discovered it
>>>was closed.
>>>
>>>And, I played with the intake on my Dad's Ranger yesterday and unplugged
>>>hoses while it was idling. Without additional gas to go along with the
>>>extra
>>>air, the fuel mixture became lean, and the engine ultimately died.
>>
>> Apples and oranges. Trying to prove your "theory" about a Jeep by
>> experimenting on a Ford really doesn't make much sense. The Ford
>> (assuming fairly late model and fuel injected) has a mass airflow
>> system and the Jeep has a speed density system. Two different ways of
>> calculating how much air is coming into the engine. The mass airflow
>> system gets lean. The speed density system adds fuel to go with the
>> additional air.
>>
>
>Really!? It can add enough fuel to blow up the motor when it should be at
>idle? That would make a very dangerous condition on the trail. Lose a vac
>line while rock crawling and immediately suffer full throttle operation in
>Low Range. That could be a serious problem, don't you think? I'm not sure my
>CJ's brakes can stop in full throttle and low range, 1st or 2nd gear.
Slow down a litlle, Einstein...
First, in order to "suffer full throttle operation", the vacuum leak
would have to be the size of the throttle body opening at WOT. Do you
see any "vac lines" of that size on your CJ? Nope! It ain't gonna
happen unexptectedly on the trail my friend.
It happens when somebody takes the intake off and doesn't get it back
on right.
As for if it can really happen... Why don't you ask the OP? Hint:
the system has no problem delivering enough fuel with the throttle
wide open. It will do the same with a massive air leak.
On later model Chrysler vehicles with plastic intakes, the PCM is
programmed to prevent this behavior in case the intake were to develop
a large crack. Havent seen an aluminum intake on a Jeep do that.
>
>Put an inexperienced driver in a situation where a vac leak might come about
>and the engine goes to full throttle operation as a result, and there can
>easily be lives in the balance.
There you go thinking too much again.
>
>I'm pretty sure that while there might be a slight increase in idle speed, I
>would not expect a condition where one would be concerned with blowing an
>engine at what is expected to be an idling situation.
It all depends on the size of the leak.
>
>
>
>>>
>>>You may be right, I'm not arguing your point. All I'm saying is that if
>>>the
>>>throttle won't move and there is full throttle operation as soon as the
>>>engine starts, I suspect the throttle is held full open, not full close.
>>>This would give lots of gas and air, any other condition would give lots
>>>of
>>>air but not much gas.
>>
>> The OP just removed the intake and replaced the exhaust manifold.
>> While he's probably nowhere near as smart as you, I'd bet he can look
>> at the throttle plate and know if it was open or closed...
>>
>
>You're right, I completely clueless -- except for the part where I converted
>my Jeep from the crappy BBD carburator to full Multi Port Fuel Injection. I
>have no idea.
You just proved that taking some parts off, and putting some others
back on doesn't require a clue as to how the system works.
Congratulations!
Since your CJ is now equipped with a speed density injection system,
with it idling, go yank a vacuum hose off and report back here what
happens.
>
>The OP is not clear that he looked, or simply noticed that the linkage would
>not move by hand.
>
>Murphy's Law states that the simplist thing to fix is the most likely
>problem. Assuming that is true, all I'm saying is that the linkage needs to
>be checked to be sure the throttle is not already full open when it is
>expected to be full closed.
>
>
>
>
>
10-07-2007, 07:20 PM
#56
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
On Sun, 07 Oct 2007 21:12:09 GMT, "Jeff Strickland"
<crwlr@verizon.net> wrote:
>
>"bllsht" <nospam@dot.net> wrote in message
>news:haeig39i876dc6o7jd4cj28ipa92iusfh0@4ax.com.. .
>> On Sun, 07 Oct 2007 18:01:52 GMT, "Jeff Strickland"
>> <crwlr@verizon.net> wrote:
>>
>>>I think he does not know. I'm working on the idea that he tried to move it
>>>by hand and it would not move, not that he looked inside and discovered it
>>>was closed.
>>>
>>>And, I played with the intake on my Dad's Ranger yesterday and unplugged
>>>hoses while it was idling. Without additional gas to go along with the
>>>extra
>>>air, the fuel mixture became lean, and the engine ultimately died.
>>
>> Apples and oranges. Trying to prove your "theory" about a Jeep by
>> experimenting on a Ford really doesn't make much sense. The Ford
>> (assuming fairly late model and fuel injected) has a mass airflow
>> system and the Jeep has a speed density system. Two different ways of
>> calculating how much air is coming into the engine. The mass airflow
>> system gets lean. The speed density system adds fuel to go with the
>> additional air.
>>
>
>Really!? It can add enough fuel to blow up the motor when it should be at
>idle? That would make a very dangerous condition on the trail. Lose a vac
>line while rock crawling and immediately suffer full throttle operation in
>Low Range. That could be a serious problem, don't you think? I'm not sure my
>CJ's brakes can stop in full throttle and low range, 1st or 2nd gear.
Slow down a litlle, Einstein...
First, in order to "suffer full throttle operation", the vacuum leak
would have to be the size of the throttle body opening at WOT. Do you
see any "vac lines" of that size on your CJ? Nope! It ain't gonna
happen unexptectedly on the trail my friend.
It happens when somebody takes the intake off and doesn't get it back
on right.
As for if it can really happen... Why don't you ask the OP? Hint:
the system has no problem delivering enough fuel with the throttle
wide open. It will do the same with a massive air leak.
On later model Chrysler vehicles with plastic intakes, the PCM is
programmed to prevent this behavior in case the intake were to develop
a large crack. Havent seen an aluminum intake on a Jeep do that.
>
>Put an inexperienced driver in a situation where a vac leak might come about
>and the engine goes to full throttle operation as a result, and there can
>easily be lives in the balance.
There you go thinking too much again.
>
>I'm pretty sure that while there might be a slight increase in idle speed, I
>would not expect a condition where one would be concerned with blowing an
>engine at what is expected to be an idling situation.
It all depends on the size of the leak.
>
>
>
>>>
>>>You may be right, I'm not arguing your point. All I'm saying is that if
>>>the
>>>throttle won't move and there is full throttle operation as soon as the
>>>engine starts, I suspect the throttle is held full open, not full close.
>>>This would give lots of gas and air, any other condition would give lots
>>>of
>>>air but not much gas.
>>
>> The OP just removed the intake and replaced the exhaust manifold.
>> While he's probably nowhere near as smart as you, I'd bet he can look
>> at the throttle plate and know if it was open or closed...
>>
>
>You're right, I completely clueless -- except for the part where I converted
>my Jeep from the crappy BBD carburator to full Multi Port Fuel Injection. I
>have no idea.
You just proved that taking some parts off, and putting some others
back on doesn't require a clue as to how the system works.
Congratulations!
Since your CJ is now equipped with a speed density injection system,
with it idling, go yank a vacuum hose off and report back here what
happens.
>
>The OP is not clear that he looked, or simply noticed that the linkage would
>not move by hand.
>
>Murphy's Law states that the simplist thing to fix is the most likely
>problem. Assuming that is true, all I'm saying is that the linkage needs to
>be checked to be sure the throttle is not already full open when it is
>expected to be full closed.
>
>
>
>
>
<crwlr@verizon.net> wrote:
>
>"bllsht" <nospam@dot.net> wrote in message
>news:haeig39i876dc6o7jd4cj28ipa92iusfh0@4ax.com.. .
>> On Sun, 07 Oct 2007 18:01:52 GMT, "Jeff Strickland"
>> <crwlr@verizon.net> wrote:
>>
>>>I think he does not know. I'm working on the idea that he tried to move it
>>>by hand and it would not move, not that he looked inside and discovered it
>>>was closed.
>>>
>>>And, I played with the intake on my Dad's Ranger yesterday and unplugged
>>>hoses while it was idling. Without additional gas to go along with the
>>>extra
>>>air, the fuel mixture became lean, and the engine ultimately died.
>>
>> Apples and oranges. Trying to prove your "theory" about a Jeep by
>> experimenting on a Ford really doesn't make much sense. The Ford
>> (assuming fairly late model and fuel injected) has a mass airflow
>> system and the Jeep has a speed density system. Two different ways of
>> calculating how much air is coming into the engine. The mass airflow
>> system gets lean. The speed density system adds fuel to go with the
>> additional air.
>>
>
>Really!? It can add enough fuel to blow up the motor when it should be at
>idle? That would make a very dangerous condition on the trail. Lose a vac
>line while rock crawling and immediately suffer full throttle operation in
>Low Range. That could be a serious problem, don't you think? I'm not sure my
>CJ's brakes can stop in full throttle and low range, 1st or 2nd gear.
Slow down a litlle, Einstein...
First, in order to "suffer full throttle operation", the vacuum leak
would have to be the size of the throttle body opening at WOT. Do you
see any "vac lines" of that size on your CJ? Nope! It ain't gonna
happen unexptectedly on the trail my friend.
It happens when somebody takes the intake off and doesn't get it back
on right.
As for if it can really happen... Why don't you ask the OP? Hint:
the system has no problem delivering enough fuel with the throttle
wide open. It will do the same with a massive air leak.
On later model Chrysler vehicles with plastic intakes, the PCM is
programmed to prevent this behavior in case the intake were to develop
a large crack. Havent seen an aluminum intake on a Jeep do that.
>
>Put an inexperienced driver in a situation where a vac leak might come about
>and the engine goes to full throttle operation as a result, and there can
>easily be lives in the balance.
There you go thinking too much again.
>
>I'm pretty sure that while there might be a slight increase in idle speed, I
>would not expect a condition where one would be concerned with blowing an
>engine at what is expected to be an idling situation.
It all depends on the size of the leak.
>
>
>
>>>
>>>You may be right, I'm not arguing your point. All I'm saying is that if
>>>the
>>>throttle won't move and there is full throttle operation as soon as the
>>>engine starts, I suspect the throttle is held full open, not full close.
>>>This would give lots of gas and air, any other condition would give lots
>>>of
>>>air but not much gas.
>>
>> The OP just removed the intake and replaced the exhaust manifold.
>> While he's probably nowhere near as smart as you, I'd bet he can look
>> at the throttle plate and know if it was open or closed...
>>
>
>You're right, I completely clueless -- except for the part where I converted
>my Jeep from the crappy BBD carburator to full Multi Port Fuel Injection. I
>have no idea.
You just proved that taking some parts off, and putting some others
back on doesn't require a clue as to how the system works.
Congratulations!
Since your CJ is now equipped with a speed density injection system,
with it idling, go yank a vacuum hose off and report back here what
happens.
>
>The OP is not clear that he looked, or simply noticed that the linkage would
>not move by hand.
>
>Murphy's Law states that the simplist thing to fix is the most likely
>problem. Assuming that is true, all I'm saying is that the linkage needs to
>be checked to be sure the throttle is not already full open when it is
>expected to be full closed.
>
>
>
>
>
10-07-2007, 07:20 PM
#57
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
On Sun, 07 Oct 2007 21:12:09 GMT, "Jeff Strickland"
<crwlr@verizon.net> wrote:
>
>"bllsht" <nospam@dot.net> wrote in message
>news:haeig39i876dc6o7jd4cj28ipa92iusfh0@4ax.com.. .
>> On Sun, 07 Oct 2007 18:01:52 GMT, "Jeff Strickland"
>> <crwlr@verizon.net> wrote:
>>
>>>I think he does not know. I'm working on the idea that he tried to move it
>>>by hand and it would not move, not that he looked inside and discovered it
>>>was closed.
>>>
>>>And, I played with the intake on my Dad's Ranger yesterday and unplugged
>>>hoses while it was idling. Without additional gas to go along with the
>>>extra
>>>air, the fuel mixture became lean, and the engine ultimately died.
>>
>> Apples and oranges. Trying to prove your "theory" about a Jeep by
>> experimenting on a Ford really doesn't make much sense. The Ford
>> (assuming fairly late model and fuel injected) has a mass airflow
>> system and the Jeep has a speed density system. Two different ways of
>> calculating how much air is coming into the engine. The mass airflow
>> system gets lean. The speed density system adds fuel to go with the
>> additional air.
>>
>
>Really!? It can add enough fuel to blow up the motor when it should be at
>idle? That would make a very dangerous condition on the trail. Lose a vac
>line while rock crawling and immediately suffer full throttle operation in
>Low Range. That could be a serious problem, don't you think? I'm not sure my
>CJ's brakes can stop in full throttle and low range, 1st or 2nd gear.
Slow down a litlle, Einstein...
First, in order to "suffer full throttle operation", the vacuum leak
would have to be the size of the throttle body opening at WOT. Do you
see any "vac lines" of that size on your CJ? Nope! It ain't gonna
happen unexptectedly on the trail my friend.
It happens when somebody takes the intake off and doesn't get it back
on right.
As for if it can really happen... Why don't you ask the OP? Hint:
the system has no problem delivering enough fuel with the throttle
wide open. It will do the same with a massive air leak.
On later model Chrysler vehicles with plastic intakes, the PCM is
programmed to prevent this behavior in case the intake were to develop
a large crack. Havent seen an aluminum intake on a Jeep do that.
>
>Put an inexperienced driver in a situation where a vac leak might come about
>and the engine goes to full throttle operation as a result, and there can
>easily be lives in the balance.
There you go thinking too much again.
>
>I'm pretty sure that while there might be a slight increase in idle speed, I
>would not expect a condition where one would be concerned with blowing an
>engine at what is expected to be an idling situation.
It all depends on the size of the leak.
>
>
>
>>>
>>>You may be right, I'm not arguing your point. All I'm saying is that if
>>>the
>>>throttle won't move and there is full throttle operation as soon as the
>>>engine starts, I suspect the throttle is held full open, not full close.
>>>This would give lots of gas and air, any other condition would give lots
>>>of
>>>air but not much gas.
>>
>> The OP just removed the intake and replaced the exhaust manifold.
>> While he's probably nowhere near as smart as you, I'd bet he can look
>> at the throttle plate and know if it was open or closed...
>>
>
>You're right, I completely clueless -- except for the part where I converted
>my Jeep from the crappy BBD carburator to full Multi Port Fuel Injection. I
>have no idea.
You just proved that taking some parts off, and putting some others
back on doesn't require a clue as to how the system works.
Congratulations!
Since your CJ is now equipped with a speed density injection system,
with it idling, go yank a vacuum hose off and report back here what
happens.
>
>The OP is not clear that he looked, or simply noticed that the linkage would
>not move by hand.
>
>Murphy's Law states that the simplist thing to fix is the most likely
>problem. Assuming that is true, all I'm saying is that the linkage needs to
>be checked to be sure the throttle is not already full open when it is
>expected to be full closed.
>
>
>
>
>
<crwlr@verizon.net> wrote:
>
>"bllsht" <nospam@dot.net> wrote in message
>news:haeig39i876dc6o7jd4cj28ipa92iusfh0@4ax.com.. .
>> On Sun, 07 Oct 2007 18:01:52 GMT, "Jeff Strickland"
>> <crwlr@verizon.net> wrote:
>>
>>>I think he does not know. I'm working on the idea that he tried to move it
>>>by hand and it would not move, not that he looked inside and discovered it
>>>was closed.
>>>
>>>And, I played with the intake on my Dad's Ranger yesterday and unplugged
>>>hoses while it was idling. Without additional gas to go along with the
>>>extra
>>>air, the fuel mixture became lean, and the engine ultimately died.
>>
>> Apples and oranges. Trying to prove your "theory" about a Jeep by
>> experimenting on a Ford really doesn't make much sense. The Ford
>> (assuming fairly late model and fuel injected) has a mass airflow
>> system and the Jeep has a speed density system. Two different ways of
>> calculating how much air is coming into the engine. The mass airflow
>> system gets lean. The speed density system adds fuel to go with the
>> additional air.
>>
>
>Really!? It can add enough fuel to blow up the motor when it should be at
>idle? That would make a very dangerous condition on the trail. Lose a vac
>line while rock crawling and immediately suffer full throttle operation in
>Low Range. That could be a serious problem, don't you think? I'm not sure my
>CJ's brakes can stop in full throttle and low range, 1st or 2nd gear.
Slow down a litlle, Einstein...
First, in order to "suffer full throttle operation", the vacuum leak
would have to be the size of the throttle body opening at WOT. Do you
see any "vac lines" of that size on your CJ? Nope! It ain't gonna
happen unexptectedly on the trail my friend.
It happens when somebody takes the intake off and doesn't get it back
on right.
As for if it can really happen... Why don't you ask the OP? Hint:
the system has no problem delivering enough fuel with the throttle
wide open. It will do the same with a massive air leak.
On later model Chrysler vehicles with plastic intakes, the PCM is
programmed to prevent this behavior in case the intake were to develop
a large crack. Havent seen an aluminum intake on a Jeep do that.
>
>Put an inexperienced driver in a situation where a vac leak might come about
>and the engine goes to full throttle operation as a result, and there can
>easily be lives in the balance.
There you go thinking too much again.
>
>I'm pretty sure that while there might be a slight increase in idle speed, I
>would not expect a condition where one would be concerned with blowing an
>engine at what is expected to be an idling situation.
It all depends on the size of the leak.
>
>
>
>>>
>>>You may be right, I'm not arguing your point. All I'm saying is that if
>>>the
>>>throttle won't move and there is full throttle operation as soon as the
>>>engine starts, I suspect the throttle is held full open, not full close.
>>>This would give lots of gas and air, any other condition would give lots
>>>of
>>>air but not much gas.
>>
>> The OP just removed the intake and replaced the exhaust manifold.
>> While he's probably nowhere near as smart as you, I'd bet he can look
>> at the throttle plate and know if it was open or closed...
>>
>
>You're right, I completely clueless -- except for the part where I converted
>my Jeep from the crappy BBD carburator to full Multi Port Fuel Injection. I
>have no idea.
You just proved that taking some parts off, and putting some others
back on doesn't require a clue as to how the system works.
Congratulations!
Since your CJ is now equipped with a speed density injection system,
with it idling, go yank a vacuum hose off and report back here what
happens.
>
>The OP is not clear that he looked, or simply noticed that the linkage would
>not move by hand.
>
>Murphy's Law states that the simplist thing to fix is the most likely
>problem. Assuming that is true, all I'm saying is that the linkage needs to
>be checked to be sure the throttle is not already full open when it is
>expected to be full closed.
>
>
>
>
>
10-08-2007, 06:18 AM
#58
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
Thanks a lot guys for your help, there does indeed seem to be a small
gap at the bottom of the intake where it sits against the head, I
could have sworn I had the intake lined up on those two little dowels,
oh well, more care next time. By the way the throttle was definately
closed and moved freely as I took the rubber air inlet thing off to
make sure, I even tied the throttle closed incase it was opening of
its own accord, but luckily something less sinister than efi computer
gremlins is the cause, thanks again.
Glenn
gap at the bottom of the intake where it sits against the head, I
could have sworn I had the intake lined up on those two little dowels,
oh well, more care next time. By the way the throttle was definately
closed and moved freely as I took the rubber air inlet thing off to
make sure, I even tied the throttle closed incase it was opening of
its own accord, but luckily something less sinister than efi computer
gremlins is the cause, thanks again.
Glenn
10-08-2007, 06:18 AM
#59
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
Thanks a lot guys for your help, there does indeed seem to be a small
gap at the bottom of the intake where it sits against the head, I
could have sworn I had the intake lined up on those two little dowels,
oh well, more care next time. By the way the throttle was definately
closed and moved freely as I took the rubber air inlet thing off to
make sure, I even tied the throttle closed incase it was opening of
its own accord, but luckily something less sinister than efi computer
gremlins is the cause, thanks again.
Glenn
gap at the bottom of the intake where it sits against the head, I
could have sworn I had the intake lined up on those two little dowels,
oh well, more care next time. By the way the throttle was definately
closed and moved freely as I took the rubber air inlet thing off to
make sure, I even tied the throttle closed incase it was opening of
its own accord, but luckily something less sinister than efi computer
gremlins is the cause, thanks again.
Glenn
10-08-2007, 06:18 AM
#60
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
Thanks a lot guys for your help, there does indeed seem to be a small
gap at the bottom of the intake where it sits against the head, I
could have sworn I had the intake lined up on those two little dowels,
oh well, more care next time. By the way the throttle was definately
closed and moved freely as I took the rubber air inlet thing off to
make sure, I even tied the throttle closed incase it was opening of
its own accord, but luckily something less sinister than efi computer
gremlins is the cause, thanks again.
Glenn
gap at the bottom of the intake where it sits against the head, I
could have sworn I had the intake lined up on those two little dowels,
oh well, more care next time. By the way the throttle was definately
closed and moved freely as I took the rubber air inlet thing off to
make sure, I even tied the throttle closed incase it was opening of
its own accord, but luckily something less sinister than efi computer
gremlins is the cause, thanks again.
Glenn