Idiot Light

[kowalski vanishing point]

My '97 GTS, the car that couldn't do anything right, now has added another layer to its mysterious shenanigans.
As I've posted before it has that annoying fast idle that I've been unable to track down. A few weeks ago the idiot light for the oil pressure came on. The pressure gauge showed normal and the engine sounded fine. I had a class reunion to go to so I took the car and drove about 100 miles. During the whole time the idiot light was on it had only a few episodes of the idle being to fast. Then the idiot light went off and I was plagued again with the fast idle.
Fast forward to this past weekend.
The idiot light started flickering on again, initially going away when I revved the engine a little but eventually only staying off when I started the car until the idle dropped down when it would go on and then stay on. Again the gauge showed fine oil pressure and the engine sounded fine so I've put another 300 miles on it, mostly cruising around Sacramento and driving back to Paradise (busy weekend).
During the whole time the idiot light is on the car has been generally idling fine. The last three hours of driving there has been NO fast idle problems at all.

Is this just coincidence?
Is the idiot light somehow connected to the solution to the fast idle problem?
I suspect that I simply have a bad pressure sender.
Which sender is the one to the idiot light
and which to the gauge? It is not clear to me from the manual.
I'll gladly unhook the idiot light if this keeps my car from doing the fast idle boogie. As annoying as that light is, the pure ecstacy of idling at a normal speed easily outweighs any nerve wracking thoughts I have while driving with it on.

And don't jump all over me for driving with the idiot light on.
This car malfunctions so often that if I drove it only when it was running smoothly it would only have 3000 miles on it and only 200 miles in the last two years. It might just be a blessing in disguise if it blew up (seriously nothing about the way it sounds or the way the other gauge reads would indicate a true oil pressure problem).

 

[MES]

I would say the 2 are unrelated, oil idiot light would be a bad sending unit or poor connection to the unit. I think you have been told this before, to check the battery and clean the terminals on the battery and under the hood.

I do have this observation to add.

I have disconnected and re-connected my computer probably 10 times for various reasons and each time it re-learns how to idle the car.

Here is how it starts. When its first re-connected it idles fine for 100-200 miles then starts to extremely high idle 1700 RPM. The car also knows how fast I'm going, because it will high idle when rolling and in neutral, then once I come to a complete stop I can watch the tach step down in 3-5 steps to normal idle. I can put it into 2nd gear while driving and the car will drive down the road at 15-20 MPH without ANY throttle, kind of like cruse control. Then over the next 100-200 miles it will start and stop the high idling intermittently, then finally after a total 500 miles or so, no more high idle EVER. This is not a leaking intake gasket, because sure enough if I reset the computer it will happen again. I don't know if this is normal or not but that's what it does.

Anyway my point is your computer may be resetting itself every once in a while due to a poor connection and hence relearning over and over the correct idle speed. That may be why yours constantly has problems with the idle. It really was NOT fun to drive with it high idling like that, so I can imagine your frustration.