XJ engine instantly revs out at start up
#31
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
I believe the OP was implying the throttle plate was 'not open at all'.
not that it 'couldn't' open at all.
Mike
Jeff Strickland wrote:
> STOP
>
> He said that the throttle does not open. I think we have to make sure it
> is not full open already before we go looking for leaks and other gremlins.
>
> I happen to agree with the leak diagnosis, but since it is reported that
> the throttle won't even open, I have to think the throttle is actually
> Full Open already, and the fact that it doesn't budge needs to be
> addressed before we start looking to gaskets and disconnected hoses.
>
>
>
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:4708ee41$0$22717$9a6e19ea@unlimited.newshosti ng.com...
>> That usually means you forgot to hook up a vacuum line. You have an
>> air leak into the intake someplace likely.
>>
>> Mike
>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
>> Canadian Off Road Trips Photos: Non members can still view!
>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> (More Off Road album links at bottom of the view page)
>>
>> Glenn wrote:
>>> Hi all, was trying to be a good brother today doing a major service
>>> and repairing the cracked exhaust manifold on my sisters 99XJ.
>>> Repairing the exhaust manifold obviously entails taking of the inlet
>>> manifold, unplugging all the wires, fuel line off the fuel rail etc.
>>> Everything went back together ok but when I fired it up, the engine
>>> raced to max revs instantly, pretty sure it would rev till blew up
>>> from the sound of it if I didn't switch it off. I can't understand how
>>> it could do this, particularly since the throttle butterfly does not
>>> open at all. I tried resetting the computer, no luck, I'm out of ideas
>>> at the moment other than towing it to the nearest Jeep dealer, Any
>>> idea's anyone???
>>>
>
not that it 'couldn't' open at all.
Mike
Jeff Strickland wrote:
> STOP
>
> He said that the throttle does not open. I think we have to make sure it
> is not full open already before we go looking for leaks and other gremlins.
>
> I happen to agree with the leak diagnosis, but since it is reported that
> the throttle won't even open, I have to think the throttle is actually
> Full Open already, and the fact that it doesn't budge needs to be
> addressed before we start looking to gaskets and disconnected hoses.
>
>
>
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:4708ee41$0$22717$9a6e19ea@unlimited.newshosti ng.com...
>> That usually means you forgot to hook up a vacuum line. You have an
>> air leak into the intake someplace likely.
>>
>> Mike
>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
>> Canadian Off Road Trips Photos: Non members can still view!
>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> (More Off Road album links at bottom of the view page)
>>
>> Glenn wrote:
>>> Hi all, was trying to be a good brother today doing a major service
>>> and repairing the cracked exhaust manifold on my sisters 99XJ.
>>> Repairing the exhaust manifold obviously entails taking of the inlet
>>> manifold, unplugging all the wires, fuel line off the fuel rail etc.
>>> Everything went back together ok but when I fired it up, the engine
>>> raced to max revs instantly, pretty sure it would rev till blew up
>>> from the sound of it if I didn't switch it off. I can't understand how
>>> it could do this, particularly since the throttle butterfly does not
>>> open at all. I tried resetting the computer, no luck, I'm out of ideas
>>> at the moment other than towing it to the nearest Jeep dealer, Any
>>> idea's anyone???
>>>
>
#32
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
I believe the OP was implying the throttle plate was 'not open at all'.
not that it 'couldn't' open at all.
Mike
Jeff Strickland wrote:
> STOP
>
> He said that the throttle does not open. I think we have to make sure it
> is not full open already before we go looking for leaks and other gremlins.
>
> I happen to agree with the leak diagnosis, but since it is reported that
> the throttle won't even open, I have to think the throttle is actually
> Full Open already, and the fact that it doesn't budge needs to be
> addressed before we start looking to gaskets and disconnected hoses.
>
>
>
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:4708ee41$0$22717$9a6e19ea@unlimited.newshosti ng.com...
>> That usually means you forgot to hook up a vacuum line. You have an
>> air leak into the intake someplace likely.
>>
>> Mike
>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
>> Canadian Off Road Trips Photos: Non members can still view!
>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> (More Off Road album links at bottom of the view page)
>>
>> Glenn wrote:
>>> Hi all, was trying to be a good brother today doing a major service
>>> and repairing the cracked exhaust manifold on my sisters 99XJ.
>>> Repairing the exhaust manifold obviously entails taking of the inlet
>>> manifold, unplugging all the wires, fuel line off the fuel rail etc.
>>> Everything went back together ok but when I fired it up, the engine
>>> raced to max revs instantly, pretty sure it would rev till blew up
>>> from the sound of it if I didn't switch it off. I can't understand how
>>> it could do this, particularly since the throttle butterfly does not
>>> open at all. I tried resetting the computer, no luck, I'm out of ideas
>>> at the moment other than towing it to the nearest Jeep dealer, Any
>>> idea's anyone???
>>>
>
not that it 'couldn't' open at all.
Mike
Jeff Strickland wrote:
> STOP
>
> He said that the throttle does not open. I think we have to make sure it
> is not full open already before we go looking for leaks and other gremlins.
>
> I happen to agree with the leak diagnosis, but since it is reported that
> the throttle won't even open, I have to think the throttle is actually
> Full Open already, and the fact that it doesn't budge needs to be
> addressed before we start looking to gaskets and disconnected hoses.
>
>
>
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:4708ee41$0$22717$9a6e19ea@unlimited.newshosti ng.com...
>> That usually means you forgot to hook up a vacuum line. You have an
>> air leak into the intake someplace likely.
>>
>> Mike
>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
>> Canadian Off Road Trips Photos: Non members can still view!
>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> (More Off Road album links at bottom of the view page)
>>
>> Glenn wrote:
>>> Hi all, was trying to be a good brother today doing a major service
>>> and repairing the cracked exhaust manifold on my sisters 99XJ.
>>> Repairing the exhaust manifold obviously entails taking of the inlet
>>> manifold, unplugging all the wires, fuel line off the fuel rail etc.
>>> Everything went back together ok but when I fired it up, the engine
>>> raced to max revs instantly, pretty sure it would rev till blew up
>>> from the sound of it if I didn't switch it off. I can't understand how
>>> it could do this, particularly since the throttle butterfly does not
>>> open at all. I tried resetting the computer, no luck, I'm out of ideas
>>> at the moment other than towing it to the nearest Jeep dealer, Any
>>> idea's anyone???
>>>
>
#33
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
I believe the OP was implying the throttle plate was 'not open at all'.
not that it 'couldn't' open at all.
Mike
Jeff Strickland wrote:
> STOP
>
> He said that the throttle does not open. I think we have to make sure it
> is not full open already before we go looking for leaks and other gremlins.
>
> I happen to agree with the leak diagnosis, but since it is reported that
> the throttle won't even open, I have to think the throttle is actually
> Full Open already, and the fact that it doesn't budge needs to be
> addressed before we start looking to gaskets and disconnected hoses.
>
>
>
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:4708ee41$0$22717$9a6e19ea@unlimited.newshosti ng.com...
>> That usually means you forgot to hook up a vacuum line. You have an
>> air leak into the intake someplace likely.
>>
>> Mike
>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
>> Canadian Off Road Trips Photos: Non members can still view!
>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> (More Off Road album links at bottom of the view page)
>>
>> Glenn wrote:
>>> Hi all, was trying to be a good brother today doing a major service
>>> and repairing the cracked exhaust manifold on my sisters 99XJ.
>>> Repairing the exhaust manifold obviously entails taking of the inlet
>>> manifold, unplugging all the wires, fuel line off the fuel rail etc.
>>> Everything went back together ok but when I fired it up, the engine
>>> raced to max revs instantly, pretty sure it would rev till blew up
>>> from the sound of it if I didn't switch it off. I can't understand how
>>> it could do this, particularly since the throttle butterfly does not
>>> open at all. I tried resetting the computer, no luck, I'm out of ideas
>>> at the moment other than towing it to the nearest Jeep dealer, Any
>>> idea's anyone???
>>>
>
not that it 'couldn't' open at all.
Mike
Jeff Strickland wrote:
> STOP
>
> He said that the throttle does not open. I think we have to make sure it
> is not full open already before we go looking for leaks and other gremlins.
>
> I happen to agree with the leak diagnosis, but since it is reported that
> the throttle won't even open, I have to think the throttle is actually
> Full Open already, and the fact that it doesn't budge needs to be
> addressed before we start looking to gaskets and disconnected hoses.
>
>
>
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:4708ee41$0$22717$9a6e19ea@unlimited.newshosti ng.com...
>> That usually means you forgot to hook up a vacuum line. You have an
>> air leak into the intake someplace likely.
>>
>> Mike
>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
>> Canadian Off Road Trips Photos: Non members can still view!
>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> (More Off Road album links at bottom of the view page)
>>
>> Glenn wrote:
>>> Hi all, was trying to be a good brother today doing a major service
>>> and repairing the cracked exhaust manifold on my sisters 99XJ.
>>> Repairing the exhaust manifold obviously entails taking of the inlet
>>> manifold, unplugging all the wires, fuel line off the fuel rail etc.
>>> Everything went back together ok but when I fired it up, the engine
>>> raced to max revs instantly, pretty sure it would rev till blew up
>>> from the sound of it if I didn't switch it off. I can't understand how
>>> it could do this, particularly since the throttle butterfly does not
>>> open at all. I tried resetting the computer, no luck, I'm out of ideas
>>> at the moment other than towing it to the nearest Jeep dealer, Any
>>> idea's anyone???
>>>
>
#34
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
Jeff Strickland wrote:
>
> Since the engine is racing AND "the throttle butterfly does not open at
> all," I suggest the trouble is that the throttle is already full open.
> This would give lots of gas, instead of just a drip, to go along with
> all of the extra air that would be needed for a runaway engine.
>
>
Naw, they run away when they have a vacuum leak, they don't stall. Even
a medium line like the one off the back corner for the inside heater
control will get them way up in the 2K's.
I also believe the OP was implying the throttle plate was 'not open at
all'. not that it 'couldn't' open at all.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
>
> Since the engine is racing AND "the throttle butterfly does not open at
> all," I suggest the trouble is that the throttle is already full open.
> This would give lots of gas, instead of just a drip, to go along with
> all of the extra air that would be needed for a runaway engine.
>
>
Naw, they run away when they have a vacuum leak, they don't stall. Even
a medium line like the one off the back corner for the inside heater
control will get them way up in the 2K's.
I also believe the OP was implying the throttle plate was 'not open at
all'. not that it 'couldn't' open at all.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
#35
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
Jeff Strickland wrote:
>
> Since the engine is racing AND "the throttle butterfly does not open at
> all," I suggest the trouble is that the throttle is already full open.
> This would give lots of gas, instead of just a drip, to go along with
> all of the extra air that would be needed for a runaway engine.
>
>
Naw, they run away when they have a vacuum leak, they don't stall. Even
a medium line like the one off the back corner for the inside heater
control will get them way up in the 2K's.
I also believe the OP was implying the throttle plate was 'not open at
all'. not that it 'couldn't' open at all.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
>
> Since the engine is racing AND "the throttle butterfly does not open at
> all," I suggest the trouble is that the throttle is already full open.
> This would give lots of gas, instead of just a drip, to go along with
> all of the extra air that would be needed for a runaway engine.
>
>
Naw, they run away when they have a vacuum leak, they don't stall. Even
a medium line like the one off the back corner for the inside heater
control will get them way up in the 2K's.
I also believe the OP was implying the throttle plate was 'not open at
all'. not that it 'couldn't' open at all.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
#36
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
Jeff Strickland wrote:
>
> Since the engine is racing AND "the throttle butterfly does not open at
> all," I suggest the trouble is that the throttle is already full open.
> This would give lots of gas, instead of just a drip, to go along with
> all of the extra air that would be needed for a runaway engine.
>
>
Naw, they run away when they have a vacuum leak, they don't stall. Even
a medium line like the one off the back corner for the inside heater
control will get them way up in the 2K's.
I also believe the OP was implying the throttle plate was 'not open at
all'. not that it 'couldn't' open at all.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
>
> Since the engine is racing AND "the throttle butterfly does not open at
> all," I suggest the trouble is that the throttle is already full open.
> This would give lots of gas, instead of just a drip, to go along with
> all of the extra air that would be needed for a runaway engine.
>
>
Naw, they run away when they have a vacuum leak, they don't stall. Even
a medium line like the one off the back corner for the inside heater
control will get them way up in the 2K's.
I also believe the OP was implying the throttle plate was 'not open at
all'. not that it 'couldn't' open at all.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
#37
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
Jeff Strickland wrote:
>
> Since the engine is racing AND "the throttle butterfly does not open at
> all," I suggest the trouble is that the throttle is already full open.
> This would give lots of gas, instead of just a drip, to go along with
> all of the extra air that would be needed for a runaway engine.
>
>
Naw, they run away when they have a vacuum leak, they don't stall. Even
a medium line like the one off the back corner for the inside heater
control will get them way up in the 2K's.
I also believe the OP was implying the throttle plate was 'not open at
all'. not that it 'couldn't' open at all.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
>
> Since the engine is racing AND "the throttle butterfly does not open at
> all," I suggest the trouble is that the throttle is already full open.
> This would give lots of gas, instead of just a drip, to go along with
> all of the extra air that would be needed for a runaway engine.
>
>
Naw, they run away when they have a vacuum leak, they don't stall. Even
a medium line like the one off the back corner for the inside heater
control will get them way up in the 2K's.
I also believe the OP was implying the throttle plate was 'not open at
all'. not that it 'couldn't' open at all.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
#38
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
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.
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.
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:47090ecf$0$11332$9a6e19ea@unlimited.newshosti ng.com...
>I believe the OP was implying the throttle plate was 'not open at all'. not
>that it 'couldn't' open at all.
>
> Mike
>
> Jeff Strickland wrote:
>> STOP
>>
>> He said that the throttle does not open. I think we have to make sure it
>> is not full open already before we go looking for leaks and other
>> gremlins.
>>
>> I happen to agree with the leak diagnosis, but since it is reported that
>> the throttle won't even open, I have to think the throttle is actually
>> Full Open already, and the fact that it doesn't budge needs to be
>> addressed before we start looking to gaskets and disconnected hoses.
>>
>>
>>
>>
>> "Mike Romain" <romainm@sympatico.ca> wrote in message
>> news:4708ee41$0$22717$9a6e19ea@unlimited.newshosti ng.com...
>>> That usually means you forgot to hook up a vacuum line. You have an air
>>> leak into the intake someplace likely.
>>>
>>> Mike
>>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
>>> Canadian Off Road Trips Photos: Non members can still view!
>>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>> (More Off Road album links at bottom of the view page)
>>>
>>> Glenn wrote:
>>>> Hi all, was trying to be a good brother today doing a major service
>>>> and repairing the cracked exhaust manifold on my sisters 99XJ.
>>>> Repairing the exhaust manifold obviously entails taking of the inlet
>>>> manifold, unplugging all the wires, fuel line off the fuel rail etc.
>>>> Everything went back together ok but when I fired it up, the engine
>>>> raced to max revs instantly, pretty sure it would rev till blew up
>>>> from the sound of it if I didn't switch it off. I can't understand how
>>>> it could do this, particularly since the throttle butterfly does not
>>>> open at all. I tried resetting the computer, no luck, I'm out of ideas
>>>> at the moment other than towing it to the nearest Jeep dealer, Any
>>>> idea's anyone???
>>>>
>>
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.
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.
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:47090ecf$0$11332$9a6e19ea@unlimited.newshosti ng.com...
>I believe the OP was implying the throttle plate was 'not open at all'. not
>that it 'couldn't' open at all.
>
> Mike
>
> Jeff Strickland wrote:
>> STOP
>>
>> He said that the throttle does not open. I think we have to make sure it
>> is not full open already before we go looking for leaks and other
>> gremlins.
>>
>> I happen to agree with the leak diagnosis, but since it is reported that
>> the throttle won't even open, I have to think the throttle is actually
>> Full Open already, and the fact that it doesn't budge needs to be
>> addressed before we start looking to gaskets and disconnected hoses.
>>
>>
>>
>>
>> "Mike Romain" <romainm@sympatico.ca> wrote in message
>> news:4708ee41$0$22717$9a6e19ea@unlimited.newshosti ng.com...
>>> That usually means you forgot to hook up a vacuum line. You have an air
>>> leak into the intake someplace likely.
>>>
>>> Mike
>>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
>>> Canadian Off Road Trips Photos: Non members can still view!
>>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>> (More Off Road album links at bottom of the view page)
>>>
>>> Glenn wrote:
>>>> Hi all, was trying to be a good brother today doing a major service
>>>> and repairing the cracked exhaust manifold on my sisters 99XJ.
>>>> Repairing the exhaust manifold obviously entails taking of the inlet
>>>> manifold, unplugging all the wires, fuel line off the fuel rail etc.
>>>> Everything went back together ok but when I fired it up, the engine
>>>> raced to max revs instantly, pretty sure it would rev till blew up
>>>> from the sound of it if I didn't switch it off. I can't understand how
>>>> it could do this, particularly since the throttle butterfly does not
>>>> open at all. I tried resetting the computer, no luck, I'm out of ideas
>>>> at the moment other than towing it to the nearest Jeep dealer, Any
>>>> idea's anyone???
>>>>
>>
#39
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
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.
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.
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:47090ecf$0$11332$9a6e19ea@unlimited.newshosti ng.com...
>I believe the OP was implying the throttle plate was 'not open at all'. not
>that it 'couldn't' open at all.
>
> Mike
>
> Jeff Strickland wrote:
>> STOP
>>
>> He said that the throttle does not open. I think we have to make sure it
>> is not full open already before we go looking for leaks and other
>> gremlins.
>>
>> I happen to agree with the leak diagnosis, but since it is reported that
>> the throttle won't even open, I have to think the throttle is actually
>> Full Open already, and the fact that it doesn't budge needs to be
>> addressed before we start looking to gaskets and disconnected hoses.
>>
>>
>>
>>
>> "Mike Romain" <romainm@sympatico.ca> wrote in message
>> news:4708ee41$0$22717$9a6e19ea@unlimited.newshosti ng.com...
>>> That usually means you forgot to hook up a vacuum line. You have an air
>>> leak into the intake someplace likely.
>>>
>>> Mike
>>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
>>> Canadian Off Road Trips Photos: Non members can still view!
>>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>> (More Off Road album links at bottom of the view page)
>>>
>>> Glenn wrote:
>>>> Hi all, was trying to be a good brother today doing a major service
>>>> and repairing the cracked exhaust manifold on my sisters 99XJ.
>>>> Repairing the exhaust manifold obviously entails taking of the inlet
>>>> manifold, unplugging all the wires, fuel line off the fuel rail etc.
>>>> Everything went back together ok but when I fired it up, the engine
>>>> raced to max revs instantly, pretty sure it would rev till blew up
>>>> from the sound of it if I didn't switch it off. I can't understand how
>>>> it could do this, particularly since the throttle butterfly does not
>>>> open at all. I tried resetting the computer, no luck, I'm out of ideas
>>>> at the moment other than towing it to the nearest Jeep dealer, Any
>>>> idea's anyone???
>>>>
>>
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.
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.
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:47090ecf$0$11332$9a6e19ea@unlimited.newshosti ng.com...
>I believe the OP was implying the throttle plate was 'not open at all'. not
>that it 'couldn't' open at all.
>
> Mike
>
> Jeff Strickland wrote:
>> STOP
>>
>> He said that the throttle does not open. I think we have to make sure it
>> is not full open already before we go looking for leaks and other
>> gremlins.
>>
>> I happen to agree with the leak diagnosis, but since it is reported that
>> the throttle won't even open, I have to think the throttle is actually
>> Full Open already, and the fact that it doesn't budge needs to be
>> addressed before we start looking to gaskets and disconnected hoses.
>>
>>
>>
>>
>> "Mike Romain" <romainm@sympatico.ca> wrote in message
>> news:4708ee41$0$22717$9a6e19ea@unlimited.newshosti ng.com...
>>> That usually means you forgot to hook up a vacuum line. You have an air
>>> leak into the intake someplace likely.
>>>
>>> Mike
>>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
>>> Canadian Off Road Trips Photos: Non members can still view!
>>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>> (More Off Road album links at bottom of the view page)
>>>
>>> Glenn wrote:
>>>> Hi all, was trying to be a good brother today doing a major service
>>>> and repairing the cracked exhaust manifold on my sisters 99XJ.
>>>> Repairing the exhaust manifold obviously entails taking of the inlet
>>>> manifold, unplugging all the wires, fuel line off the fuel rail etc.
>>>> Everything went back together ok but when I fired it up, the engine
>>>> raced to max revs instantly, pretty sure it would rev till blew up
>>>> from the sound of it if I didn't switch it off. I can't understand how
>>>> it could do this, particularly since the throttle butterfly does not
>>>> open at all. I tried resetting the computer, no luck, I'm out of ideas
>>>> at the moment other than towing it to the nearest Jeep dealer, Any
>>>> idea's anyone???
>>>>
>>
#40
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
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.
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.
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:47090ecf$0$11332$9a6e19ea@unlimited.newshosti ng.com...
>I believe the OP was implying the throttle plate was 'not open at all'. not
>that it 'couldn't' open at all.
>
> Mike
>
> Jeff Strickland wrote:
>> STOP
>>
>> He said that the throttle does not open. I think we have to make sure it
>> is not full open already before we go looking for leaks and other
>> gremlins.
>>
>> I happen to agree with the leak diagnosis, but since it is reported that
>> the throttle won't even open, I have to think the throttle is actually
>> Full Open already, and the fact that it doesn't budge needs to be
>> addressed before we start looking to gaskets and disconnected hoses.
>>
>>
>>
>>
>> "Mike Romain" <romainm@sympatico.ca> wrote in message
>> news:4708ee41$0$22717$9a6e19ea@unlimited.newshosti ng.com...
>>> That usually means you forgot to hook up a vacuum line. You have an air
>>> leak into the intake someplace likely.
>>>
>>> Mike
>>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
>>> Canadian Off Road Trips Photos: Non members can still view!
>>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>> (More Off Road album links at bottom of the view page)
>>>
>>> Glenn wrote:
>>>> Hi all, was trying to be a good brother today doing a major service
>>>> and repairing the cracked exhaust manifold on my sisters 99XJ.
>>>> Repairing the exhaust manifold obviously entails taking of the inlet
>>>> manifold, unplugging all the wires, fuel line off the fuel rail etc.
>>>> Everything went back together ok but when I fired it up, the engine
>>>> raced to max revs instantly, pretty sure it would rev till blew up
>>>> from the sound of it if I didn't switch it off. I can't understand how
>>>> it could do this, particularly since the throttle butterfly does not
>>>> open at all. I tried resetting the computer, no luck, I'm out of ideas
>>>> at the moment other than towing it to the nearest Jeep dealer, Any
>>>> idea's anyone???
>>>>
>>
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.
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.
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:47090ecf$0$11332$9a6e19ea@unlimited.newshosti ng.com...
>I believe the OP was implying the throttle plate was 'not open at all'. not
>that it 'couldn't' open at all.
>
> Mike
>
> Jeff Strickland wrote:
>> STOP
>>
>> He said that the throttle does not open. I think we have to make sure it
>> is not full open already before we go looking for leaks and other
>> gremlins.
>>
>> I happen to agree with the leak diagnosis, but since it is reported that
>> the throttle won't even open, I have to think the throttle is actually
>> Full Open already, and the fact that it doesn't budge needs to be
>> addressed before we start looking to gaskets and disconnected hoses.
>>
>>
>>
>>
>> "Mike Romain" <romainm@sympatico.ca> wrote in message
>> news:4708ee41$0$22717$9a6e19ea@unlimited.newshosti ng.com...
>>> That usually means you forgot to hook up a vacuum line. You have an air
>>> leak into the intake someplace likely.
>>>
>>> Mike
>>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
>>> Canadian Off Road Trips Photos: Non members can still view!
>>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>> (More Off Road album links at bottom of the view page)
>>>
>>> Glenn wrote:
>>>> Hi all, was trying to be a good brother today doing a major service
>>>> and repairing the cracked exhaust manifold on my sisters 99XJ.
>>>> Repairing the exhaust manifold obviously entails taking of the inlet
>>>> manifold, unplugging all the wires, fuel line off the fuel rail etc.
>>>> Everything went back together ok but when I fired it up, the engine
>>>> raced to max revs instantly, pretty sure it would rev till blew up
>>>> from the sound of it if I didn't switch it off. I can't understand how
>>>> it could do this, particularly since the throttle butterfly does not
>>>> open at all. I tried resetting the computer, no luck, I'm out of ideas
>>>> at the moment other than towing it to the nearest Jeep dealer, Any
>>>> idea's anyone???
>>>>
>>