Engine stalls after running fine... NEED SOME HELP

[RegDunlop]

Thanks
is there any way to test the ignition coils? While on the vehicle?

I recall seeing on youtube a mechanic disconnect the wire from the coil and put a short piece of vaccuum tubing between wire and coil then useing a voltage detctor to test it?

Anybody know if that works?

Any other way?

edit to add: here is the youtube clip I was refering to
http://www.youtube.com/watch?v=5-wJH-KUFsM&feature=fvwrel

 

[RegDunlop]

WOuld bad ignition coils cause that type of stalling?

 

[willix]

The circuitry for the fuel system is the reason why pumps go out.

The pump pull a high load and connections through out the system often heat & burn up terminals for the fuse, relay, top of the tank, & in the tank.

When the car is running feel the fuse & the relay and observe if they get hot.

This heat will make the terminal loose its tension and the mating connector can move around & loosing contact and arc & weld it self to the terminal temporary.

Pull the fuse & the relay and look for evidence of arcing on the contacts and replace or clean up termainals male & female.

The bottom line is the current load the pump needs is being deminished by the resistance at these terminals and the end result is low volts to the pump.

Volts at the fuse need to be checked with a VOM, a test light won't tell you the volts. The pump operating under low volts is slaving to keep up and prematurely wearing.

When ever you install a pump you are aways advised to splice in a new connector and this is the reason why.

 

[RegDunlop]

Thanks Wilix I checked fuses and relays today. I didt see any evidence of overheating or blown fuses

Thanks again

 

[willix]

The coils would fail individually and there are 3 of them so if you are driving along and a coil malfuntioned it would just start running badly.

There is a module at the coil base plate that may cause stalling.

But I would suspect the CPS as this sensor will just cut fuel & ignition operation.

If you were to observe the tach when the engine quits it will just drop out dead to "0" and cranking the engine will not get tach needle movement at starting rpms. The tachometer gets its signal from the CPS.

This would be a good indication of the CPS failure.

 

[willix]

Do you have any fault codes? Having a fault code to base a solution or direction to go eliminates a lot of guesswork.

Guesswork is expensive without luck and usually steers you in a direction of the cheapest or the least amount of work It becomes a waste of time & money.

 

[willix]

If you have a 4 terminal oil pressure switch (down buy the filter)

2 of those terminals complete the fuel pump circuit.

 

[nwjones18]

This might help you out. I know my obd1 scanner for my 88 f-150 has been helpful.

http://www.amazon.com/Equus-3123-GM-Code...4091&sr=8-1

 

[RegDunlop]

Thanks for all the help. I was going to bring it to the mechanic today, but I ordered a new IAC and TPS , and will completely remove the TB and clean it thoroughly before giving upo and going to the mechanic.

Thanks for all the suggestions re: reading the codes, but this car is an ODDBALL.

It has a GM OBD so called 1.5 system. IE, it has an OBD 1 computer with an OBD 2 16 pin connector. Impossible to find for under $500, and getting a shop to read it---well I may as well just bring it to my mech.

 

[The_Eric]

If the car suddenly dies going down the road, the IAC is not to blame.

 

[MarkM66]

This might help you with your codes;

http://www.extreme-check-engine-light-codes.com/GM OBD1 Decoder.htm

I had something similar happen to me with my '85 S10. Going down the road, it would severely loose power, and bring up a lean code, but never died. It turned out to be a rubber connection of the fuel pump to fuel line on the sending unit in the tank. The connection developed a leak, and would slowly loose pressure causing the engine to run lean. Lucky for me, the hole never got big enough to leave me stranded.

I would check fuel pressure, just to rule that out.

Check your codes, and report back.

 

[RegDunlop]

Originally Posted By: The_Eric
If the car suddenly dies going down the road, the IAC is not to blame.


Thanks, why would it not be the iac?

 

[SteveSRT8]

The iac is IDLE air control.

It can indeed cause a stall if the throttle is reduced to idle while rolling. It's also typical for the idle to be erratic or too fast.

It will throw a code.

 

[meep]

tried hair drier on ECU yet? hint...hint...