torque converter solenoid...

[sampkamp]

I got a 1990 Grand Prix with a 3.1 that had been sitting for 3 years. On the first drive home after buying it.. it died about a mile from where I got it at a stop light. It started back up and I drove home without anymore stalling problems. Well I read it may be the torque converter solenoid. So I disconnected it ( well I think thats what I unhooked? ) I took it for a SHORT test drive and it was fine till I got in my driveway..when I put it in park it died. Well today I took it for its third drive..about 15 miles mostly highway. When I got to my destination it died, then stalled everytime I started it and put it into drive unless I gave it a bunch of gas. From what I read this STILL sounds like the converter being locked in after a long drive... I also read that once its disconnected you lose overdrive but I still have it!? The wire harness I unhooked was on the transmission, facing towards the front of the car, under the air filter and had five wires. Nothing new has gone wrong since I disconnected that wire so.. I assume it was the right one. I tried to replicate the problem on the way home, I stopped..put it in park and back into drive but nothing happened.. it operated fine..

Any ideas what else I can do? DID I unhook the correct wire? I looked online but cant find a diagram to show its location..

This is probably unrelated but I should mention it.. the low gas and oil pressure lights are always on and the odometer doesnt work but the speedometer and temp guage are working... These have always been stuck on...

THANK YOU SO MUCH

[GTP Dad]

Welcome to AF!!

It sounds like you unhooked the proper plug on the transmission. I would check the oil pressure sending unit and replace it. You should find it above the oil filter. It looks like a small can and on most of these cars the fuel pump will shut off it the oil pressure drops too low as read by the computer.
If you change it you should get a good reading and the shutting off issue should stop. If that doesn't cure it you will need to change the crank position sensor. I may be going bad and causing the stalling problem.

[tblake]

GTPDAD, not that I doubt you at all, just want to increase my knowledge....

How come your so sure the oil pressure sending unit is the problem? Just previous experiences?

[GTP Dad]

Low oil pressure will cause the engine to shut down due as a fail safe to prevent the engine from being ruined. If the pressure drops too low a switch will shut the fuel pump down and it will stall. Since he indicated the car had a low oil pressure light on all the time the pressure may be dropping too low when it gets hot and the pump is stopping. This will also turn off that stupid light if the sending unit is indeed bad.

[sampkamp]

Originally Posted by GTP Dad

Low oil pressure will cause the engine to shut down due as a fail safe to prevent the engine from being ruined. If the pressure drops too low a switch will shut the fuel pump down and it will stall. Since he indicated the car had a low oil pressure light on all the time the pressure may be dropping too low when it gets hot and the pump is stopping. This will also turn off that stupid light if the sending unit is indeed bad.

I'll have to look into this. I figured the light was on because of some instrument panel error since the fuel light is on too and the odometer isnt working. Thanks!

[tblake]

Originally Posted by GTP Dad

Low oil pressure will cause the engine to shut down due as a fail safe to prevent the engine from being ruined. If the pressure drops too low a switch will shut the fuel pump down and it will stall. Since he indicated the car had a low oil pressure light on all the time the pressure may be dropping too low when it gets hot and the pump is stopping. This will also turn off that stupid light if the sending unit is indeed bad.

Hmmmm, I thought that the fuel pump relay and oil pressure sensor ran in parallel to supply power to the pump....

Could he just do a quick test by removing the fuel pump relay and attempt to start the car? If its starts, could we conclude that there is adequate oil pressure?

[GTP Dad]

Remember you are dealing with a 1990 vintage car not a newer version. He could remove the fuel pump relay and try to start it but it won't start anyway. The oil pressure light is troublesome and the sensor is probably bad anyway so he can kill two issues at one time.