In my 1984 I had a new FP relay and when the oil pressure on the IP said 9 psi it stalled. I put an external oil cooler on my 89 the oil line got loose. I lost all oil pressure and it stalled. My friend had his 02 Corvette worked on by the guys in NJ that put the dual turbos in the rear of the car. The car kept stalling. He brought the car to Chevy. It was the oil pressure switch. Just saying.

 

Sure but if there are 2 feeds and one is dead and the other is dying, fixing the dying feed would allow the car to run.

Did they fix the back up circuit and call it good or did they make sure the other circuit is also working?

 

What was said that the only way the oil pressure sender switch would kill the engine is if the FP relay was no good. And in the FSM it says that the oil pressure switch is a back up for power to the fuel pump. I will say that I never checked to see if the wiring to the the FP relay had any issues. So even with a new relay if the wiring were defective then the you could be correct. All I am saying is that in three situations I am familiar with. Each time that switch failed the cars would not run. And Marc's 02 was his baby. The car had less than 10K miles. I can't believe the wiring to the FP was nfg and when the switch went bad the car stalled.
But, I could be wrong or mis-interpreting what you are explaining.

 

That is exactly what I am saying. If the Oil Pressure Switch is the make or break between walking and driving, your primary circuit has an issue that you didn't notice because the switch is covering for it.

 

I think that is what the FSM says. So there must have been something wrong with the FP relay. And when I lost oil pressure the switch killed it. So if that is true. If a Corvette is running and the FP relay is working correctly. You should be able to remove the wires from the oil pressure switch and the car will continue to run. Correct?

 

IIRC, I did it accidentally years ago when I forgot to connect the switch.

 

And the car continued to run without the pressure switch connected?

 

I don't think I discovered it instantly. IIRC it was one of those "Hey! What's this?" moments.

 

Okay but did the car continue to run without the switch connected. Thank you

 

YES!! The fkn thing will run with the switch disconnected.

 

It did until I discovered it. So either something was wrong with my harness or it can run without just that you don't have a backup circuit so if the primary fails, you are SOL

 

not sure where you're at with this, but reading thru this thread is somewhat confusing. from the above, my first thought is the fuel filter. unless I missed it, nowhere did I read anything about a replacement. have you run a fuel pressure test?

 

Just trying to be clear. I thought that you meant the car was running and the switch was disconnected. Like I said just checking. Oh and frankly I would never curse at someone by email. Should be done face to face.

 

It works disconnected or not. Disconnected you can crank and run.

 

Thank you.

 

That can be arranged. Jump in your conveyance of choice and scurry on up here. My location is noted in my avatar, unlike the ones who lurk here and hide their whereabouts.

 

On the C4 that has the intermittent shut downs I also would advise that you look for a loose or broken connection/s. When I first bought my C4 it was "missing" every so often and it was the red wire going into the distributor that had a broken retaining clip. A new end for the wire and that problem disappeared. I also found bad crimps on the terminals on the fuel pump relay and lots of corroded connectors. I also had a bad connection at the oil pressure switches which was causing problems on my 1988 C4 starting. Be sure that you have full battery voltage (or very close) at the fuse panel, if not you might have a low voltage issue causing your pump to stop. While you are at it check your grounds and ground straps, they too can cause issues.

I had a issue once when the wire from my fuel pump relay to the fuel pump had a small hole in the insulation. Inside the outer jacket of the wire was corrosion and this made resistance and when the power was passed through the wire. After a couple minutes of running the wire heated up and the pump shut off due to low power getting through the wire's corrosion. I spent days trying to solve this problem until I ran a temporary wire to the fuel pump and it ran with no issues after that. A faulty piece of 12 gauge wire was enough to stop the car from running.

How warm was the engine when this happened? I had thick oil and one morning I did a brisk 0-80 getting onto the highway and my oil pressure dropped dramatically and recovered a few seconds later. The oil pressure gauge dropped to a low number and restored itself a few seconds afterwards. I pulled over and saw that the oil was mostly in the valve covers and since it was not completely warmed up after ~2 miles it all built up in the valve covers. I changed to a thinner oil and the problem went away and I have never been able to re-produce the problem. I do have screens to keep parts out of the bottom end but I had never seen oil fill the Valve Covers full like that. At that time I did have a High pressure High Volume Melling oil pump and I promptly change the spring to reduce the pressure inside the Big Block.

Good Luck and I hope that your problem is solved soon so you can enjoy that Corvette of yours!

Best Regards,
Chris

 

This is a great post. Thank you