1990 L98 C4 nightmare
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Burning Brakes
Joined: Aug 2005
Posts: 798
Likes: 2
From: Notorious Miami sunny south florida
1990 L98 C4 nightmare
Just picked up a 1990 it was starting at first but once you shut it down you would have to spray starter fluid after it cooled down to re start it this went on for about a week then you'd try again an it would start and stall so I was told may be the a fuel problem so I replaced the filter no go fuel pump nog the coil no coil in the distributor the anti theft bypass plug wires new injectors I'm not.getting injector pulse it will start with fuel. If you spray the throttle body but will stall. Once it's out it you continue to spray constant ly she will run stop it stalls I'm out of ideas please help
Melting Slicks
Joined: Jan 2014
Posts: 2,187
Likes: 381
From: Lunenburg MA
It sounds like you're throwing parts at it without diagnosing it. You need an ODBI scanner, a fuel pressure gauge, and a vacuum gauge, and the factory service manual so you can see what's going on.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
1990
There’s a few things you can try.
1. check fuel pump fuse. It’s on the right door jamb near the hinges.
2. Jumper the oil pressure switch connector.
behind the distributor there is a rubber plug on the oil pressure switch.
jumper that plug with a paper clip
( don’t let it touch ground or u will blow the fuel pump fuse.) it’s hot all the time.
your pump should start running.
Go to the back of the car and take off the gas cap and listen for the pump running.
if it’s not running, use a small rubber hammer,not a steel hammer, and rap the fuel pump relay a couple times, but not hard then go listen again.
3. Remove jumper, and on the right-side of the engine there is a test port on the fuel rail, remove the cap on the rail test port, put a rag on the manifold, and push the pin on the port in with your fingernail.
if it spurts, you should have fuel pressure. No gas means pump or relay might be bad.
if fuel filter blocked up again, u need to clean out the tank.
1. check fuel pump fuse. It’s on the right door jamb near the hinges.
2. Jumper the oil pressure switch connector.
behind the distributor there is a rubber plug on the oil pressure switch.
jumper that plug with a paper clip
( don’t let it touch ground or u will blow the fuel pump fuse.) it’s hot all the time.
your pump should start running.
Go to the back of the car and take off the gas cap and listen for the pump running.
if it’s not running, use a small rubber hammer,not a steel hammer, and rap the fuel pump relay a couple times, but not hard then go listen again.
3. Remove jumper, and on the right-side of the engine there is a test port on the fuel rail, remove the cap on the rail test port, put a rag on the manifold, and push the pin on the port in with your fingernail.
if it spurts, you should have fuel pressure. No gas means pump or relay might be bad.
if fuel filter blocked up again, u need to clean out the tank.
8th Gear
Joined: May 2017
Posts: 8
Likes: 2
Hello! I was having trouble starting mine when cold. It would start some days but others not. It would start with starter fluid. So, I took it in to Tony’s Corvette. Tony found that my distributor and coil needed to be replaced. It was not send pulses on start up. After two years trying to figure it out, Tony did it! Thank you Tony!
Safety Car
Joined: May 2001
Posts: 4,754
Likes: 1,642
From: Fairfax Virginia
That would likely be the "High Energy Module" with it's 7 terminals (Inside the distributor) or something inside the distributor not sending the signal. If not the HEI then it might have something to do with the Hall Effect sensor and Pickup inside the distributor
The Electronic Spark Control unit "could" possibly be suspect as well.
I would go through the wiring to be sure that the wiring connecting the Distributor is connected and working. I found a broken locking tab on the power wire feeding the distributor that was causing intermittent shut off's.
Let us know how the Corvette progress towards getting back on the street, we all want to learn.
Best Regards,
Chris
The Electronic Spark Control unit "could" possibly be suspect as well.
I would go through the wiring to be sure that the wiring connecting the Distributor is connected and working. I found a broken locking tab on the power wire feeding the distributor that was causing intermittent shut off's.
Let us know how the Corvette progress towards getting back on the street, we all want to learn.
Best Regards,
Chris
