1993 Cadillac El Dorado Engine Stalls

lawisnotblind · Posted at Mon Jun 29, 2009 7:35 pm

Engine Performance problem
1993 Cadillac El Dorado V8 Front Wheel Drive Automatic 104000 miles

This is the problem for me. Over the past year, the fuel sending unit was replaced, along with the gas filter, fuel pressure regulator, map sensor, ait sensor, tps, new plugs & wires and both crankshaft sensors. Also, I have no codes. When I first start the car it runs absolutely great. Drove up to the freeway and went 10 miles one way and returned. I was driving down my street @ 25 mph and paused to turn into driveway and the car quietly and suddenly stalled. The temp reached and remain at around 203-212 degrees. At one point it reached 223 and immediately went back to 207. I drove the car around town the next day and while leaving the post office, I pulled to the stop sign and it just stalled again. It restarts immediately and I drove home with no problems at all, but I did notice that it did began to feel like it was running a bit rough. The next day, I drove it and after about 30 mins of running around town, it stalled again and took about 4 tries to restart in about 3 mins. My brother has the exact same kind of car, model and year and no problems at all. Can anyone offer any ideas? My wife will no longer touch the car!!!

Thank you, Cliff

gstacey · Posted at Mon Jun 29, 2009 9:48 pm

Does it have the original plugs and wires(wires will have cyl# on them). It could be electrical interference from the wires causing the ignition control to shut down. It could also have an EGR valve sticking open, although at 25 mph you should get little/no EGR. Typically after the egr goes to 100%(45mph-), it sticks full open and dies after cruising.

lawisnotblind · Posted at Mon Jun 29, 2009 10:47 pm

Thanks for responding. The plugs and wires were also changed. The EGR valve was NOT changed, but I did attempt to clean it out some time ago.

gstacey · Posted at Tue Jun 30, 2009 8:11 pm

Never had much success with cleaning them out. If the egr is sticking, it will run rough, you can keep it running with throttle though, it is basically a large vacuum leak. If it won't start, tap on the base of it with something metallic, and see if it changes. Or even try tapping on it if it is running rough. One other thing to consider, and may be the higher of the probabilities, is the idle speed control motor. It has a nose switch as part of the unit, and if that switch is still indicating the throttle at idle when it is not, it will retract all the way trying to control the speed, and the result will be a stall. This can also create a hard start for a short time until the shaft extends opening the throttle plate. Considering your conditions, and this happening around town, it is the strongest of the possibilities. You might be able to confirm this by disconnecting the isc when the vehicle is at a decent idle speed, and driving like you've been. If it no longer stalls, plug it in and see if it returns. Or, check it after a stall. If the ISC shaft is fully retracted to where there is a gap between it and the cam, that is your cause.

lawisnotblind · Posted at Thu Jul 02, 2009 6:55 pm

Hi gstacy, since I changed the plugs and checked all wires for proper resistance, I'll change the ISC and see what happens. If that doesn't do it, I'll also change the EGR valve. I might even do both, one after the other. So if the ISC works, I may still do the EGR for preventiveness. I'll let you know. Thanks so much, Cliff

gstacey · Posted at Thu Jul 02, 2009 8:35 pm

You may run into an issue with having to do an idle learn to clear a check engine light, after an ISC replacement.

lawisnotblind · Posted at Thu Jul 02, 2009 9:27 pm

I understand what you are saying about the idle learn and I just read a page that gave an 18 step procedure for doing a TP sensor/idle learn procedure, so once I replace the ISC, i'll do this procedure. Thanks for the heads up.

Cliff