jseremba

Hi Everybody,

I own a 1989 6 spd manual Corvette. It has been shutting off. I bought a new idle position sensor, no luck. the car runs fine and then shuts off. after a few minutes it will restart and run well.
It has new fuel injectors, 1 month.
New fuel pump and fuel filter probably 7000 miles on them and new less than 200 miles MAF relays. Throttle Position Sensor is brand new.
The oil pressure is 40/45 when it starts and after a while goes down to 20/25.
Could the oil pressure switch have a problem that and it is intermittent.
I stalled on the way home last week and almost needed to be towed home. I reliazed that if I when in gear kept the car at 1800 or more RPM it did not stall. Interestingly enough it idle at lights without a problem.
Today it stalled at a light. I got help pushing it to the side and then it restarted, probably 10 minutes. Drove home 1o minutes without incident. Idles like a rock.
My low coolant light is coming on and off. About 1000 miles ago I changed all of the sensors.
Thank you

antfarmer2

Test the fuel pressure with a gauge on the windshield when driving if that is good look for spark then test your icm and coil. Most part store's do it for free hit a few many do not know what they are doing.

Benny42

Oil pressure WILL NOT CAUSE YOUR ENGINE TO DIE unless it seizes up from no oil. You have another issue such as I.A.C. or an ignition module going bad on you. '89 was in the Multec injector time. Check ignition coil and fuel injectors

jseremba

This engine will shut off if something is wrong with the oil pressure switch. Remember if the Corvettes oil pressure goes below 10 PSI the car shuts off, to protect the engine. A friend of mine had east coast supercharging work on the car. The car stalled on the way to his job. It eventually went to Chevrolet and it was the oil pressure switch.
Both, auto zone and advanced auto said that they no longer check ICM. I had IAC problems on my truck. It only stalled when slowing down. This is stalling with the exception of the event on Saturday with the car cruising at low RPM. Idle is strong and no SES.

Thank you

Benny42

This is wrong. If your fuel pump relay is good, the engine will not shut off from low oil pressure. Look at the wiring diagram in the service manual. No such protection is provided. I can read a schematic.

jseremba

Okay, I am very bad at reading schematics. But, when I installed the external oil cooler on my 1984 and the line fell off. The engine shut down. The fuel pump relay overrides the oil pressure switch for 2 seconds so that the engine can start and pressurize. Try it. Pull the sender wires when the car is running. It will shut off.

Thank you anyway

Benny42

This has been fought out several times. If your fuel pump relay is good, the oil pressure switch will not stop the motor. The fuel pump relay is controlled by the ECM to run the pump as long as the distributor is turning. The oil pressure switch is there to let the car start if the relay fails, not the other way around.

Back to the issue at hand. My '86 acted very similarly, totally random stall at cruise. I rebuilt my distributor, every part, pick up coil, module, condenser and harness. I used O'reillys better line of parts, BWD and my issue is cured. I do hope you get it fixed.

WVZR-1

I had a "coil in cap" HEI that seemed to have similar issues, I checked internal distributor harness and pole-piece/pick up coil connector was pretty corroded. I wanted to do pole-piece and others said it couldn't be the issue(they wanted to do module harness etc), I did just the pole-piece as a "prove a point" thing more than anything else. There were no more issues. If I had done it all they would have insisted a module or harness fixed it and the distributor removal/tear down was time wasted. I thought it was just a heat-soak issue and I believe I was right. The other thing mine would do is if I shut it off for say a quick fuel stop, go to start and get a "crank - no start", let it cool, crank and drive off. It's been many years but I don't recall mine stalling frequently. Others wanted to do ECM and lots of crazy stuff.

jseremba

It seems like I have two votes for the distributor. I bought the ICM earlier today. I was trying to change the Oil Pressure switch and ran out of time. I will complete the Oil pressure switch and the ICM and definitely replace the pick up Thank you

jseremba

Okay truce on the oil pressure issue. And Thank you for the help. I already have the ICM. I will purchase the pickup and see if that helps. Thank you.