Oil Pressure Light/Dies when given gas

VaSteve · 04:53 PM

1983 SC 3.0 - stock except MSD ignition.

This weekend I did the HPDC in Summit Point, approximately 60 miles from home. I drove through 1 hour of torrential rain with no problem. During the fist instruction session (slaloms) the oil/brake light came on. The instruction suggested I was low, and I was - so I added 2 quarts - light wouldn't go out, but the car ran fine. Temperature normal ~ (9 o'clock to 9:30 position.) At idle, pressure was ~ 1 bar. If I revved it up, at about 1.5 bar the lights would go out. The tech chair thought it might be just the switch. Having missed one of these events before due to other mechanical problems, I decided to run the car the rest of the day. The car seemingly ran fine for the event (several times the car was cooling off). When I started it again, the light didn't immediately come on, but when it did it needed maybe 3 bar on the pressure gauge to turn off. I drove it home with the top off and didn't notice any unusual sounds, though the light stayed on.

Exhausted I let it sit overnight. This afternoon, I wanted to test it out. Cranked over ok and would idle, but when I hit the gas, I got a muffled "puh" sound. Hit it again and got a louder "puh" sound and it stopped running. So I opened the airbox and put it back together. (don't know if the pop-off popped) Cranked it over again, and let it idle - seemed OK. I repeated the start, idle, gas scenario and got the "puh", stall again. So I opened the airbox and thought I heard the pop off snapping back into place. At this point I gave up.

Here is some other data:
* Yesterday, rained like hell in the AM and then cleared up. Maybe mid-70's by the evening. Today it was high 60's and beatiful without a cloud in the sky.
* I have heard the car backfire before and at the time it was not like the "puh" more like a gunshot complete with smoke. (That time I had an ignition problem and was cranking and cranking - so maybe more gas). If it was a backfire this time, it was far far far more subdued.

I'm at a loss...someone please suggest something.

Thanks
Steve

VaSteve · 09-19-2004, 07:10 PM

Bump for those up late and the west coasters. Here's a photo of the car in question...

Eagledriver · 09-19-2004, 07:20 PM

I think you have two unrelated problems. Sounds like the oil pressure switch is failing since you are seeing good oil pressure. You may have water on you're wiring somewhere from the rain causing ignition or fuel injection problems. Is the weather cooler and this is just normal for your car in cooler weather? Are you just so freaked out about the oil light that you are imagining the other problem?

-Andy

VaSteve · 09-20-2004, 04:05 AM

I wish I was imagining the other problem.

It was definitely conking out when I gave it gas. The temperature had dropped a bunch overnight, but I have driven it in this temperature weather before with no problems.

If it was a backfire/pop off issue - I thought that only happened on start-up....

VaSteve · 09-20-2004, 05:46 PM

Andy, I think you're right. I tried again tonight. Started fine, revved fine, no back fires, no oil lights. I gave it a nice flogging (well for me anyhow) through the country. Fun!