not running
Thread Starter
Intermediate
Joined: Jan 2006
Posts: 27
Likes: 0
not running
ok I am stumped on this need some help
I have a 91 L98 was rebiult and bored new cam roller rockers ect.
after rebuild car would not start took to the shop they said fuel pump went out and replaced it
drove the car after this 2 time most the time it would take out just fine
and then it would act like it runs out of gas
now it just dont go at all it will start and if you rev it up it just seam to be out of gas
and dies
it will idel
have changed the fuel pump agian also the filter and swaped the ecm
nothing seam to help
I have a 91 L98 was rebiult and bored new cam roller rockers ect.
after rebuild car would not start took to the shop they said fuel pump went out and replaced it
drove the car after this 2 time most the time it would take out just fine
and then it would act like it runs out of gas
now it just dont go at all it will start and if you rev it up it just seam to be out of gas
and dies
it will idel
have changed the fuel pump agian also the filter and swaped the ecm
nothing seam to help
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
Have you had-or can you attach a fuel pressure guage to the schrader valve to see what kind of fuel pressure you have? Also, by doing that you should be able to see if the pressure drops dramatically after you shut it down which MAY point to injector problems.
Burning Brakes
Joined: Jun 2004
Posts: 752
Likes: 0
From: richardson tx
i was just reading my service book and kinda sounds like egr sticking open per the book where as its drowning the cyc with the extra air. try disconnecting the vacume line then starting the car.
Racer
Joined: Feb 2004
Posts: 265
Likes: 1
From: Irwindale Ca
check the pressure at the shrader valve. If your sitting in the car its directly in front of the passenger in the engine compartment. It looks like a tire inflator valve. I actually used a tire gauge to check the pressure. Might have a squirt of gas or two but harmless. And the gas might eat the internals of the pressure gauge but mine is still doing fine. Sounds like clogged cats or possibly fuel starvation. check Air fuel spark....
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Thread Starter
Intermediate
Joined: Jan 2006
Posts: 27
Likes: 0
took the vac line off the egr made no difference
it looks like the cats are gone it seams to have 2 small turbo type mufflers welded in there place and flow masters on the rear
the car will start and run some if you hold the fuel open just a little and you can get the car to roll this is how I move it
last nite it was sitting and running and then it reved up a bit
and ran out of fuel
got it to run agian an moved it into the shop
when it trys to run the whole engine shakes like it is trying to stay running bad enough the hood will slam down but then it dies
it looks like the cats are gone it seams to have 2 small turbo type mufflers welded in there place and flow masters on the rear
the car will start and run some if you hold the fuel open just a little and you can get the car to roll this is how I move it
last nite it was sitting and running and then it reved up a bit
and ran out of fuel
got it to run agian an moved it into the shop
when it trys to run the whole engine shakes like it is trying to stay running bad enough the hood will slam down but then it dies
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
Have you pulled any spark plugs? Almost sounds like it's flooding-I'd probably check the plugs first. Your fuel pressure sounds good-and it doesn't sound like leaky injector(s) accept holding the pedal down to get it started?.No cats. No codes??.Kinda hard to diagnos if no codes.Any more info you can give us?
And if you can get it running-even at a rough idle check for vacum leaks!!!!
And if you can get it running-even at a rough idle check for vacum leaks!!!!
Last edited by rick lambert; Jan 13, 2006 at 04:25 PM.
Burning Brakes
Joined: Nov 2005
Posts: 848
Likes: 1
From: 1992 LT1 6 speed Cayman Islands
Could be spark related as you seem to have plenty of fuel preassure.
I had a similar problem on my 92 recently where car would die when reved up, problem was a bad connection on the IAC that was loosing contact when the engine revved and vibrated causing rough running or engine shut down like it was running out of gas as it sometimes coughed alot before dying.
Check all connections between ECM and Opti. One on top of manifold, one at the coil, one at the ICM one at the opti.
If you can shake them and recreate the proplen then you have found the problem. Clean it up or replace the plug.
Hope this helps
Jerris
I had a similar problem on my 92 recently where car would die when reved up, problem was a bad connection on the IAC that was loosing contact when the engine revved and vibrated causing rough running or engine shut down like it was running out of gas as it sometimes coughed alot before dying.
Check all connections between ECM and Opti. One on top of manifold, one at the coil, one at the ICM one at the opti.
If you can shake them and recreate the proplen then you have found the problem. Clean it up or replace the plug.
Hope this helps
Jerris
Thread Starter
Intermediate
Joined: Jan 2006
Posts: 27
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ok can get it to run some changed the plugs checked for vac leaks seams ok
checked codes all that comes up is a 12 then on 4 it has ---
1.0 is blank
the left side of engine dont seam to run at all the exhast pipes are cold
number one will fire some times
checked codes all that comes up is a 12 then on 4 it has ---
1.0 is blank
the left side of engine dont seam to run at all the exhast pipes are cold
number one will fire some times
Thread Starter
Intermediate
Joined: Jan 2006
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droped the pipes at the manifolds made no differance
seam like the left side not running pulled 3 plug that I just put in looks dry checked for spark looks good
compression was 140 fuses checked fine
car runs real rich fuel makes your eyes burn
swapped ecm agian still the same
seam like the left side not running pulled 3 plug that I just put in looks dry checked for spark looks good
compression was 140 fuses checked fine
car runs real rich fuel makes your eyes burn
swapped ecm agian still the same
Thread Starter
Intermediate
Joined: Jan 2006
Posts: 27
Likes: 0
ok checked injectors one on a cyl 1 which I belive is firing its 16.4 ohms cyl 3 which I dont think fires checked at 2.4
so this could be injectors what size do I need to put in
it does have a bigger cam and bored .030 over
so this could be injectors what size do I need to put in
it does have a bigger cam and bored .030 over
Melting Slicks
Joined: Feb 2002
Posts: 2,699
Likes: 2
From: The Black Hole LA
I'd suggest a vaccum leak. Think about it, it will idle when the throttle body blades are closed. When you open them the engine is fed more air than it needs because its sucking air from else where and it dies.
Its also a good assumption because you said that the shop changed the cam which requires removal of the intake. The intake on these cars has alot of vaccum hoses that are brittle and easy to break after 15 years of use, and also the intake itself is prone to leaking where the runners fit to the plenum and manifold.
You could try the old trick (if you can get it to idle) of spraying starter fluid in the aerosol can around the vaccum hoses and intake parts. If it hits a leak the engine should rev up. If you are having a problem of getting it to idle, get someone to place their hand over the throttle body while starting the car. I mention this because I had a bad leak when I took my intake apart before and a hand over the tb was only way to keep it idling.
Its also a good assumption because you said that the shop changed the cam which requires removal of the intake. The intake on these cars has alot of vaccum hoses that are brittle and easy to break after 15 years of use, and also the intake itself is prone to leaking where the runners fit to the plenum and manifold.
You could try the old trick (if you can get it to idle) of spraying starter fluid in the aerosol can around the vaccum hoses and intake parts. If it hits a leak the engine should rev up. If you are having a problem of getting it to idle, get someone to place their hand over the throttle body while starting the car. I mention this because I had a bad leak when I took my intake apart before and a hand over the tb was only way to keep it idling.