Mechanics

S/C INTERMITTENT STALLING WHILE IDLING

1995 Buick Riviera

Engine Performance problem
1995 Buick Riviera 6 cyl Front Wheel Drive Automatic

Hello all. I've got a 1995 Buick Riviera S/C with a rather annoying engine problem. I've got ~151,000 miles on the car, and have:

Replaced the S/C, and all pulleys and belts.
CAM Sensor
Crank Sensor
EGR Valve
3 Coil Packs
and Fuel Filter.

Sporadically out of nowhere, the car will stall while idling stopped at a traffic light. Sometimes it will refire immediately, others it takes about a minute or two.

I have noticed occasionally when driving that the PRND321 light will flash and all interior gauges will reset, and once in a while the Outside Temperature on the heater control will flash.

Sometimes, from a cold start if I overrev the accelerator, the car will just sputter and stall -- also sometimes when cold cranking, it will sound like the car " backfires" and then starts.

Also, the ABS light constantly stays on (but I doubt that has anything to do with this problem).

I'd like to just push the car into the river but I've gone too deep into my pocket already to just get rid of it. Hopefully it's an easy fix, but I'm not so sure. No mechanic can seem to get it right, so I've turned to the internet! Thanks for any and all help!
Avatar
Echz
October 21, 2008.



The backfire when starting is leading me to suspect the coil or coil pack. To test I would measure resistance across the tops of coils and they should be relatively the same, if you find one that is real high then I would suspect that is the culprit. Let me know.

Tiny
Mastertechtim
Oct 22, 2008.
I tested across all 3 coils. The topmost coil came back with a reading of 1.425 and the middle and lower coils came back with a reading of ~1.38 if I recall correctly.

I also read a service bulletin somewhere that describes my symptoms, I believe it related to the Torque Converter Clutch solenoid -- it said something to the effect of " feels like a manual trans when the clutch is pulled out while in gear at a complete stop.&Quot; I'm out of ideas at this point except for plugs and wires (which were replaced ~40k ago) -- I had them pulled and the mechanic said the one he could get to looked fine. I'm sure that it's going to cost an arm and a leg for a tuneup in that the rear 3 plugs seem impossible to get to.

Just like Ricky Bobby, I WANNA GO FAST!. But the car doesn't seem to want to : )

Thanks!

Tiny
Echz
Oct 22, 2008.
The tcc problem will run at idle but will die violently when put in gear and is usually only in the 3 speed transmission. The resistance of the coil towers should be 5000 to 8000 ohms. Double check

Tiny
Mastertechtim
Oct 22, 2008.
On the Ohmmeter that I have, on the 20k setting the topmost coil is coming in at 6.63 and the two lower coils are registering 6.3 a piece

Tiny
Echz
Oct 22, 2008.
Thats fine. Try checking them when its cold, thats when I would find that one coil would read o/l or open, it would still work but very weak. But bottom line is we need to find out what we are losing to find exact problem. This is the course of action I would use to diagnose this problem. First I would install a fuel pressure gauge and constantly monitor fuel pressure, I would duct tape it to the windshield, second I would install a injector noid light in series with the fuel injector to monitor injector pulse and also I would install a spark checker and monitor spark when the condition is present. I realize this may be difficult for you to do as you might not have all these tools. A couple things you can check is I would double check the wiring connector on the crank sensor, check for loose terminals, some may be open a little and not compressing the terminal on the crank sensor, also lightly tug on the wires at the plug to make sure none of the wires are broken inside the insulation.

Tiny
Mastertechtim
Oct 22, 2008.
My does the same exact every now and then if I use good gas it does it less but I notice that my coolant would run low every time my riv would act up the was something I found on the internet about 95 riv had an intake manitfold leaking problem it would leak coolant into the engine havn't tried it yet

Tiny
Supernovahjc
Nov 3, 2008.