Please help me solve this!!

I have a 87 with a 2.9 V-6 and a automatic. I have replaced the ign, module and the fuel pump relay. But the truck still stalls on me
while driving. It doesn't do it all the time. When it does it has been at differant times, warmed up and still cold, driving and not driving. Usually, it will start up and then die again. If you let it sit for a couple minutes it will fire right up and be fine. Some times while driving it will it 0 on the tach and then jump right up to normal again. I can't keep pulling over in traffic when it dies. I don't know what else to try.

Please Help me Out.

Thanks,

Jesse

 

I'm pretty sure the tachometer signal is generated from the same signal that drives the ignition primary circuitry. When the tach. goes to zero the ignition is not receiving the signal from the TFI module, and you will not have a spark.
You could have an intermittent connection somewhere in the ignition primary (ground, power, etc) or maybe the ignition pickup inside the distributor is intermittent.
Mark

 

Just a thought.....
My wife has an almost identical truck ('88) that HAD the same problem.
I chased that demon for months. Ends up, there was some moisture trapped in the main connector for the CPU. When I removed the computer, one of the pins was almost completely corroded away. It broke when I touched it. Replacing the computer was $500 back then, and I wasn't about to pay that much. Since I work with electronics all the time, I had the neccesary tools available to make the repair. I ended up splicing a wire directly from the mother board in the computer to the wire side of the connector. Making the diagnosis was easy once the connector was removed. Green is NOT good.
If you want more instructions on this fix, post here, and I'll help you out as best I can.
Good luck!
P.S. The stalling ended immediately after I installed the bypass on the connector.

 

Hi, I know the frustration you are going through. Your problem could be alot of things so you are going to have to at least isolate why your truck is stalling. When things get complicated or seem hopeless it is best to go back to basics. The first thing I would suspect is your spark. Next time it dies(if possible run it in your driveway!) leave the key on and remove a plug wire. Continue to crank it and see if you still have spark. Even though you have changed your ignition module you may have something else interfering with your spark. A crack in your ignition cap can give this same symptom (dieing when it feels like it!) so if your cap isn't fairly new I would replace it. If your spark is good then check your fuel filter. There is one on the left frame rail near your engine. My owners manual said it should be good for the life of the vehicle! Yeah right, well mine clogged up at 98,000 miles causing intermediant fuel supply and you guessed it, stalling! I know I didn't solve your problem but maybe I at least put you on the right trail. One last thing, because it is doing it when it is cold and hot it still has the symptom of your ignition module or at least something else electronic. I have seen ignition modules be bad right off the shelve (especially aftermarket ones) so don't rule that out until you can prove you have good constant spark. Ken

 

I had a similer problem with my '87. Then one day it would not start at all. Lucky for me it was in my driveway AND it was quiet. I noticed that I couldn't hear the fuel pump when I turned the key to on. That emergency fuel pump breaker on the transmission hump had a crappy connection and was turning the fuel pump on and off. I fixed the connection and have had NO more problems with that.

Pull back your carpet and make sure the connector is doing its job.

Tony G.

 

 

My 87 Bronco II 2.9, intermittently died at low speeds and during take offs. Fuel regulator was the fix for me.
Good luck