91 Festiva GL EFI Stalls while idling or driving

[milehighbear]

I have a 93 and at times my car would stall and once in awhile would start back up. Then one day it died and would not. Mine had to do with dizzy going bad. To eliminate that, when it don't start after it dies, see if it has spark. If you have a remote starter switch, you can take the one lead off starter and connect one alligator clip to that connector on the starter and the other where red cable from battery connects to starter. Doing it this way bypasses the need to push clutch pedal in and you can hold the spark plug wire to a ground to see if there is spark. When was last time you changed the gas filter??

[scottyparade]

I have a 93 and at times my car would stall and once in awhile would start back up. Then one day it died and would not. Mine had to do with dizzy going bad. To eliminate that, when it don't start after it dies, see if it has spark. If you have a remote starter switch, you can take the one lead off starter and connect one alligator clip to that connector on the starter and the other where red cable from battery connects to starter. Doing it this way bypasses the need to push clutch pedal in and you can hold the spark plug wire to a ground to see if there is spark. When was last time you changed the gas filter??

I can check for spark tomorrow as well. My festy has yet to die totally, and not start back up, however. It purrs, beautifully, and then...death. Like an Act of God, or something. And then, sometimes it will start back up like nothing is wrong, and then sometimes it refuses to start immediately, but it will always crank up eventually.

Fuel filter was changed when we changed the fuel pump for the first time, so 5-6 months ago?

[koRnhead]

A video of it acting up could be a benefit.

[Movin]

Is it possible the first mechanics added fuel and it started??
The pump and relay may not have been bad??
Noid light the injectors..You may be losing power to them
or losing the circuit that controls them through the computer.
A noid light is a cheap electrical LED tester for checking injectors
electrically.

[scottyparade]

Is it possible the first mechanics added fuel and it started??
The pump and relay may not have been bad??
Noid light the injectors..You may be losing power to them
or losing the circuit that controls them through the computer.
A noid light is a cheap electrical LED tester for checking injectors
electrically.

I have also thought about noid light since when I cleaned the injectors, it seemed to have cleared up the problem, even though it didn't. That will be my next thing to check after the VAF and checking for a spark.

[scottyparade]

I've been hunting for a good walk through of the testing procedure of the VAF, but I couldn't find something comprehensive. Can anyone point me at a thread that can help?

[georgeb]

Best thing to do is swap another VAF if it is suspect.

[scottyparade]

Best thing to do is swap another VAF if it is suspect.

I don't have another one handy, unfortunately. If anyone is close to Atlanta, I'd be happy to pay someone to bring one to check out! Or if someone has an extra they'd like to sell, lemme know.

[georgeb]

The Haynes has some info on testing the VAF. The VAF does three things: Energizes the fuel pump circuit, measures airflow, and measures air temp. I can't find it in my manual, but somewhere it says what will happen if there is a malfunction of certain components causing it to run in "open loop" mode. And I don't recall the airflow or temp malfunctioning causing the car to die. A problem with the airflow will throw an 8 code and the temp a 10 code but the car should still run. I don't think the VAF is your problem and I would move on to the dist, coil and maybe injector signal. Did you check for spark after it dies?

[Bert]

I am currently facing a very similar problem. Car died a few times last week for no reason while driving but would quickly restart. So I changed the pump yesterday (what a noisy piece of junk the new one is) but it does work. Drove off with come confidence yesterday afternoon and then car died again. You can hear the pump priming but the car wouldn't restart at all this time around and had to tow it home last night. Haven't starting looking around (aside from obvious wires) yet and resurrected one of my other Festys for now. But will be following this thread with interest.

[georgeb]

I am currently facing a very similar problem. Car died a few times last week for no reason while driving but would quickly restart. So I changed the pump yesterday (what a noisy piece of junk the new one is) but it does work. Drove off with come confidence yesterday afternoon and then car died again. You can hear the pump priming but the car wouldn't restart at all this time around and had to tow it home last night. Haven't starting looking around (aside from obvious wires) yet and resurrected one of my other Festys for now. But will be following this thread with interest.

You heard it priming? There is some disagreement here whether these pumps prime or not. I say they don't.

[scottyparade]

Here is a video of the car dying. What you are watching on the DMM is the VAF. I have a back probe on the ECM probing the VAF terminal and ground. As you can see the voltage jumps while it is dying. No idea if I am observing a symptom or cause but I thought it might clue someone in...

Another video of the car not starting and then starting and dying a couple of times. I realize that maybe a view of the engine compartment might be helpful but I didn't have a helper. I'll post another if you guys think it would be informative.

[georgeb]

According to a pic in the Haynes manual: Holding the VAF plug in your hand the leftmost pin should read 12V (key on), the next is ground, then VAF ground, then REF (5V), VAT GND, then SIG. Last pin is empty. Other than checking the two terminals with voltage, I don't know what can be determined by backprobing while running. Did you check for spark after it died?

[Bert]

georgeb: You never hear OEM pumps but unfortunately I now have 2 aftermarket pumps on my cars. I am told OEM pumps are no longer available. The Delphi-made one I just put in is noisy and you can hear it start up and then diminish in pitch immediately when the key turns on. To me that is a priming sound.

[eurotiva]

Another easy check is pull the small vacuum line from the fuel pressure regulator (small mushroom shaped thing) at the end of the fuel rail. If you smell gas then its bad. Ethanol hurts these old rubber diaphrams.