looking for help 91 L98

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Feb 9, 2015 | 06:08 PM

woody41

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looking for help 91 L98

I was driving my 91 and the engine cut off, had to be towed home. Car was running good, it just stopped. Engine will start after it sits but immediately stalls out. Found several issues, screen on fuel pump was clogged, plugs were loose (after fuel pump/plug replacement from Chevy dealer previous/original owner less than 2500 miles ago) I replaced fuel pump, new pump screen, fuel filter, correct plugs installed and gapped, new wires, cap, coil, TPS, MAP sensor. No change, 77,000 mile car. Workshop manual trouble shooting flow chart shows to check fusible links (ckts 480B/480C)?? This is my first Corvette I'm used to electrical issues as I have been driving, racing, and restoring British Sports cars since 1974, tow truck driver said sounded like it was the throttle body, also been told to check theft deterent system?? Sorry for long post just looking for some help as I really like the car, Daytona yellow 6 speed Targa top. Was running good cruise control would hold steady at 110 mph. Any ideas? has 50 lbs fuel pressure when cranking engine. All AC/Delco parts. Thanks

Last edited by woody41; Feb 9, 2015 at 06:16 PM.

Feb 9, 2015 | 06:27 PM

Jaxley

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From: Raleigh NC

Have a way of checking spark at plug? (i've used timing light and/or a little induction light)
Borrow a noid light from Auto where ever to check your injector pulsing.
VATS could be an issue, post the operation of the security light while trying to crank it.

all i can think of right now.

Feb 10, 2015 | 08:52 AM

woody41

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Quote:

Originally Posted by Jaxley

Thanks, I checked and have spark, car started immediately and died (again) it is driving my crazy.

Feb 10, 2015 | 09:34 AM

Jaxley

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From: Raleigh NC

will it run better with starting fluid? trying to figure out if it dies from no spark/bad timing or if it dies because the fuel stops getting injected. If the fuel system was all gunked up, it's possible the screens on the injectors are gunked up too.

Double check the firing order and the timing?

What does the security light do when you get in and turn the key?

Feb 10, 2015 | 12:25 PM

Red 91

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My guess it is the ignition control module in the dist. under the roter, use a quality part and make sure to use heat sink compound. Good luck!

Feb 10, 2015 | 02:09 PM

Tom400CFI

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From: Park City Utah

Quote:

Originally Posted by Red 91

My guess it is the ignition control module in the dist. under the roter, !

Not likely if...

Quote:

Originally Posted by woody41

Thanks, I checked and have spark,

The question is, you had spark even when it wouldn't run? If so, it's not the module or anything ignition related. After confirming no spark during no run condition, I would check fuel pressure next, and confirm fuel pump operation; ~2 seconds after key one, and any time engine is turning.

Last edited by Tom400CFI; Feb 10, 2015 at 02:11 PM.

Feb 10, 2015 | 05:13 PM

Churchkey

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From: Cherokee National Forest TN

Injectors are batch fire if one shorts/fails the rest could be or are effected.

Ohm test each injector while the E plug is disconnected they all should read 14 to 16 ohms, anything less = a failed injector.

Feb 11, 2015 | 09:03 AM

woody41

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Quote:

Originally Posted by Tom400CFI

Not likely if...
The question is, you had spark even when it wouldn't run? If so, it's not the module or anything ignition related. After confirming no spark during no run condition, I would check fuel pressure next, and confirm fuel pump operation; ~2 seconds after key one, and any time engine is turning.

Double checked spark last night, after it cranks/fires/dies, there is nothing on my timing light, I have had issues in the past with an ignition module, new Delco one on the way. Fuel pressure is at 50lbs when cranking. I want to say thanks for all the help.....I thought Corvette people were a tight group, now I know. Going to double check ohms on injectors also. After all the issues from the dealer service who knows, they were supposed to be replaced. If spark plugs were not installed correctly what else did they not do. I changed all 8 plugs, correctly torqued, and anti seized (just a dot!!) in 2.25 hours....Thanks again for all the guidance....