92' LT1 engine keeps stalling
Thread Starter
4th Gear
Joined: Mar 2024
Posts: 4
Likes: 0
92' LT1 engine keeps stalling
I'm 18 and recently bought a 1992 Corvette with 165,000 miles on it. I drove the car home after purchasing it, and it ran pretty well for about 200 miles. I was driving it to work about 2 weeks later and it randomly just stalled on the highway 4 times within about 5 miles. On the drive home, it did the same thing, it ran fine for about 10 minutes then it started to stall over and over again. It still runs but it's running very rich, and it sounds like a misfire in one of the cylinders, which might be unrelated to the problem.
The diagnostics I've done so far are wiring the fuel pump directly to the battery with a switch, which did nothing. New ignition coil pack. I got a brand-new battery and spark plugs, still no help. I will be changing the plug wires to try and fix what I believe is a misfire.
If anyone has any idea what it could be besides an ECM that would be very helpful because I do not feel like spending that kind of money on the computer for it to do nothing.
The diagnostics I've done so far are wiring the fuel pump directly to the battery with a switch, which did nothing. New ignition coil pack. I got a brand-new battery and spark plugs, still no help. I will be changing the plug wires to try and fix what I believe is a misfire.
If anyone has any idea what it could be besides an ECM that would be very helpful because I do not feel like spending that kind of money on the computer for it to do nothing.
Le Mans Master
Joined: Feb 2000
Posts: 9,061
Likes: 214
From: Epping NH
I assume you've done the very basic stuff like replacing the fuel filter and ensuring the plug wires are in good shape? Have you pulled any codes to see if anything pops up?
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https://corvette-c4.com/how-to-pull-...des-1984-1994/
Burning Brakes
Joined: May 2018
Posts: 940
Likes: 242
From: Fruita CO
Before you hang anymore new parts, you need to wait for advise from forum members. They have a wealth of knowledge. You should buy a Factory Service Manual for your 92. Don't waste your money on a Chiltons.
Team Owner
Joined: Aug 2008
Posts: 33,044
Likes: 6,551
From: Rochester NY
St. Jude Donor '09 thru '26
And don't get discouraged. These are old cars and they DO need tweaking, especially if the previous owner left some problems unsolved. Each thing you correct will be a step in the right direction.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
Check the fuel pressure at idle and then shut the car off. Is the pressure rapidly bleeds down over a few minutes, you have a fuel pressure issue which could be the pump or the regulator or leaking injectors
Check the resistance of each injector. Pop the connector off each injector and use an ohm meter. LT1 injectors are 12-14 ohms +/- an ohm or two. If you have one that's single digits (ie "3 ohms" sort of thing) or open (infinite resistance), that injector is bad. They need to be checked cold (ie first thing in the morning) and also with the car at operating temp.
If the fuel pressure is bleeding down, pull the vacuum line off the fuel pressure regulator (FPR) and make sure there's no fuel in the line. If "yes", the regulator is bad. If "no", remove the injector rail and injectors from the intake. Turn key to "On" to power the pump and look for drips from the injector tips. If you see drips, the injector(s) is/are bad
There's an ignition module bolted on the front of the passenger side cylinder head. When these fail, they usually work when cold/cool and then fail when they get hot. When the fail, the engine simply stops running. After the module cools, the engine will run fine again. To be clear....I'm talking about the module and not the coil which you said you replaced.Check the resistance of each injector. Pop the connector off each injector and use an ohm meter. LT1 injectors are 12-14 ohms +/- an ohm or two. If you have one that's single digits (ie "3 ohms" sort of thing) or open (infinite resistance), that injector is bad. They need to be checked cold (ie first thing in the morning) and also with the car at operating temp.
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Burning Brakes
Joined: Jun 2021
Posts: 1,199
Likes: 449
From: NJ
Check the fuel pressure at idle and then shut the car off. Is the pressure rapidly bleeds down over a few minutes, you have a fuel pressure issue which could be the pump or the regulator or leaking injectors
Check the resistance of each injector. Pop the connector off each injector and use an ohm meter. LT1 injectors are 12-14 ohms +/- an ohm or two. If you have one that's single digits (ie "3 ohms" sort of thing) or open (infinite resistance), that injector is bad. They need to be checked cold (ie first thing in the morning) and also with the car at operating temp.
If the fuel pressure is bleeding down, pull the vacuum line off the fuel pressure regulator (FPR) and make sure there's no fuel in the line. If "yes", the regulator is bad. If "no", remove the injector rail and injectors from the intake. Turn key to "On" to power the pump and look for drips from the injector tips. If you see drips, the injector(s) is/are bad
There's an ignition module bolted on the front of the passenger side cylinder head. When these fail, they usually work when cold/cool and then fail when they get hot. When the fail, the engine simply stops running. After the module cools, the engine will run fine again. To be clear....I'm talking about the module and not the coil which you said you replaced.Check the resistance of each injector. Pop the connector off each injector and use an ohm meter. LT1 injectors are 12-14 ohms +/- an ohm or two. If you have one that's single digits (ie "3 ohms" sort of thing) or open (infinite resistance), that injector is bad. They need to be checked cold (ie first thing in the morning) and also with the car at operating temp.