XJ engine instantly revs out at start up
#61
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
#62
Guest
Posts: n/a
Re: Re: Re: XJ engine instantly revs out at start up
On Sun, 07 Oct 2007 16:30:58 GMT, "Jeff Strickland"
<crwlr@verizon.net> wrote:
>Think about this for a second. The Fuel Injector Timing is going to dictate
>the fuel delivery, and if there is a drop of gas (as should exist in an idle
>condition) but a flood of air, the result ought not be a racing engine. If
>the engine was supposed to be at idle, and one disconnected vacuum ports and
>left them open, the engine would stall, it would not run away. For it to run
>away, it needs both gas and air. The throttle is full open, not full closed.
Your theory is good but you must rememebr that fuel flow is dictacted
by MAP pressure and it would inject more fuel at high manifold
pressures caused by leak. The TPS sensor play little roll in mixture
as it is mainly used to smooth trasitions in power levels and to lean
mixture out in WOT starts to clear flooding.
>
>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.
On a fuel injected engine the throttle vale is just a air flow control
valve and engine does not really care where air comes from, valve or
leak. It will make power unlike a carbed or most TBI engines.
-----------------
TheSnoMan.com
<crwlr@verizon.net> wrote:
>Think about this for a second. The Fuel Injector Timing is going to dictate
>the fuel delivery, and if there is a drop of gas (as should exist in an idle
>condition) but a flood of air, the result ought not be a racing engine. If
>the engine was supposed to be at idle, and one disconnected vacuum ports and
>left them open, the engine would stall, it would not run away. For it to run
>away, it needs both gas and air. The throttle is full open, not full closed.
Your theory is good but you must rememebr that fuel flow is dictacted
by MAP pressure and it would inject more fuel at high manifold
pressures caused by leak. The TPS sensor play little roll in mixture
as it is mainly used to smooth trasitions in power levels and to lean
mixture out in WOT starts to clear flooding.
>
>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.
On a fuel injected engine the throttle vale is just a air flow control
valve and engine does not really care where air comes from, valve or
leak. It will make power unlike a carbed or most TBI engines.
-----------------
TheSnoMan.com
#63
Guest
Posts: n/a
Re: Re: Re: XJ engine instantly revs out at start up
On Sun, 07 Oct 2007 16:30:58 GMT, "Jeff Strickland"
<crwlr@verizon.net> wrote:
>Think about this for a second. The Fuel Injector Timing is going to dictate
>the fuel delivery, and if there is a drop of gas (as should exist in an idle
>condition) but a flood of air, the result ought not be a racing engine. If
>the engine was supposed to be at idle, and one disconnected vacuum ports and
>left them open, the engine would stall, it would not run away. For it to run
>away, it needs both gas and air. The throttle is full open, not full closed.
Your theory is good but you must rememebr that fuel flow is dictacted
by MAP pressure and it would inject more fuel at high manifold
pressures caused by leak. The TPS sensor play little roll in mixture
as it is mainly used to smooth trasitions in power levels and to lean
mixture out in WOT starts to clear flooding.
>
>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.
On a fuel injected engine the throttle vale is just a air flow control
valve and engine does not really care where air comes from, valve or
leak. It will make power unlike a carbed or most TBI engines.
-----------------
TheSnoMan.com
<crwlr@verizon.net> wrote:
>Think about this for a second. The Fuel Injector Timing is going to dictate
>the fuel delivery, and if there is a drop of gas (as should exist in an idle
>condition) but a flood of air, the result ought not be a racing engine. If
>the engine was supposed to be at idle, and one disconnected vacuum ports and
>left them open, the engine would stall, it would not run away. For it to run
>away, it needs both gas and air. The throttle is full open, not full closed.
Your theory is good but you must rememebr that fuel flow is dictacted
by MAP pressure and it would inject more fuel at high manifold
pressures caused by leak. The TPS sensor play little roll in mixture
as it is mainly used to smooth trasitions in power levels and to lean
mixture out in WOT starts to clear flooding.
>
>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.
On a fuel injected engine the throttle vale is just a air flow control
valve and engine does not really care where air comes from, valve or
leak. It will make power unlike a carbed or most TBI engines.
-----------------
TheSnoMan.com
#64
Guest
Posts: n/a
Re: Re: Re: XJ engine instantly revs out at start up
On Sun, 07 Oct 2007 16:30:58 GMT, "Jeff Strickland"
<crwlr@verizon.net> wrote:
>Think about this for a second. The Fuel Injector Timing is going to dictate
>the fuel delivery, and if there is a drop of gas (as should exist in an idle
>condition) but a flood of air, the result ought not be a racing engine. If
>the engine was supposed to be at idle, and one disconnected vacuum ports and
>left them open, the engine would stall, it would not run away. For it to run
>away, it needs both gas and air. The throttle is full open, not full closed.
Your theory is good but you must rememebr that fuel flow is dictacted
by MAP pressure and it would inject more fuel at high manifold
pressures caused by leak. The TPS sensor play little roll in mixture
as it is mainly used to smooth trasitions in power levels and to lean
mixture out in WOT starts to clear flooding.
>
>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.
On a fuel injected engine the throttle vale is just a air flow control
valve and engine does not really care where air comes from, valve or
leak. It will make power unlike a carbed or most TBI engines.
-----------------
TheSnoMan.com
<crwlr@verizon.net> wrote:
>Think about this for a second. The Fuel Injector Timing is going to dictate
>the fuel delivery, and if there is a drop of gas (as should exist in an idle
>condition) but a flood of air, the result ought not be a racing engine. If
>the engine was supposed to be at idle, and one disconnected vacuum ports and
>left them open, the engine would stall, it would not run away. For it to run
>away, it needs both gas and air. The throttle is full open, not full closed.
Your theory is good but you must rememebr that fuel flow is dictacted
by MAP pressure and it would inject more fuel at high manifold
pressures caused by leak. The TPS sensor play little roll in mixture
as it is mainly used to smooth trasitions in power levels and to lean
mixture out in WOT starts to clear flooding.
>
>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.
On a fuel injected engine the throttle vale is just a air flow control
valve and engine does not really care where air comes from, valve or
leak. It will make power unlike a carbed or most TBI engines.
-----------------
TheSnoMan.com
#65
Guest
Posts: n/a
Re: Re: Re: XJ engine instantly revs out at start up
On Sun, 07 Oct 2007 16:30:58 GMT, "Jeff Strickland"
<crwlr@verizon.net> wrote:
>Think about this for a second. The Fuel Injector Timing is going to dictate
>the fuel delivery, and if there is a drop of gas (as should exist in an idle
>condition) but a flood of air, the result ought not be a racing engine. If
>the engine was supposed to be at idle, and one disconnected vacuum ports and
>left them open, the engine would stall, it would not run away. For it to run
>away, it needs both gas and air. The throttle is full open, not full closed.
Your theory is good but you must rememebr that fuel flow is dictacted
by MAP pressure and it would inject more fuel at high manifold
pressures caused by leak. The TPS sensor play little roll in mixture
as it is mainly used to smooth trasitions in power levels and to lean
mixture out in WOT starts to clear flooding.
>
>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.
On a fuel injected engine the throttle vale is just a air flow control
valve and engine does not really care where air comes from, valve or
leak. It will make power unlike a carbed or most TBI engines.
-----------------
TheSnoMan.com
<crwlr@verizon.net> wrote:
>Think about this for a second. The Fuel Injector Timing is going to dictate
>the fuel delivery, and if there is a drop of gas (as should exist in an idle
>condition) but a flood of air, the result ought not be a racing engine. If
>the engine was supposed to be at idle, and one disconnected vacuum ports and
>left them open, the engine would stall, it would not run away. For it to run
>away, it needs both gas and air. The throttle is full open, not full closed.
Your theory is good but you must rememebr that fuel flow is dictacted
by MAP pressure and it would inject more fuel at high manifold
pressures caused by leak. The TPS sensor play little roll in mixture
as it is mainly used to smooth trasitions in power levels and to lean
mixture out in WOT starts to clear flooding.
>
>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.
On a fuel injected engine the throttle vale is just a air flow control
valve and engine does not really care where air comes from, valve or
leak. It will make power unlike a carbed or most TBI engines.
-----------------
TheSnoMan.com
#66
Guest
Posts: n/a
Re: Re: XJ engine instantly revs out at start up
On Mon, 08 Oct 2007 03:18:23 -0700, Glenn <jeepthing66@hotmail.com>
wrote:
>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
I suspected as such. Glad you found the problem. Must have been a
pretty fair sized gap.
-----------------
TheSnoMan.com
wrote:
>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
I suspected as such. Glad you found the problem. Must have been a
pretty fair sized gap.
-----------------
TheSnoMan.com
#67
Guest
Posts: n/a
Re: Re: XJ engine instantly revs out at start up
On Mon, 08 Oct 2007 03:18:23 -0700, Glenn <jeepthing66@hotmail.com>
wrote:
>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
I suspected as such. Glad you found the problem. Must have been a
pretty fair sized gap.
-----------------
TheSnoMan.com
wrote:
>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
I suspected as such. Glad you found the problem. Must have been a
pretty fair sized gap.
-----------------
TheSnoMan.com
#68
Guest
Posts: n/a
Re: Re: XJ engine instantly revs out at start up
On Mon, 08 Oct 2007 03:18:23 -0700, Glenn <jeepthing66@hotmail.com>
wrote:
>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
I suspected as such. Glad you found the problem. Must have been a
pretty fair sized gap.
-----------------
TheSnoMan.com
wrote:
>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
I suspected as such. Glad you found the problem. Must have been a
pretty fair sized gap.
-----------------
TheSnoMan.com
#69
Guest
Posts: n/a
Re: Re: XJ engine instantly revs out at start up
On Mon, 08 Oct 2007 03:18:23 -0700, Glenn <jeepthing66@hotmail.com>
wrote:
>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
I suspected as such. Glad you found the problem. Must have been a
pretty fair sized gap.
-----------------
TheSnoMan.com
wrote:
>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
I suspected as such. Glad you found the problem. Must have been a
pretty fair sized gap.
-----------------
TheSnoMan.com
#70
Guest
Posts: n/a
Re: XJ engine instantly revs out at start up
Okay, the throttle moves freely, that was not clear and it seems to be the
first thing to check.
You found the problem, the intake manifold was not seated.
"Glenn" <jeepthing66@hotmail.com> wrote in message
news:1191838703.668217.63740@v3g2000hsg.googlegrou ps.com...
> 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
>
first thing to check.
You found the problem, the intake manifold was not seated.
"Glenn" <jeepthing66@hotmail.com> wrote in message
news:1191838703.668217.63740@v3g2000hsg.googlegrou ps.com...
> 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
>