1987 2.9l Stalling

[Phroggy46]

I've got a 1987 Ranger 2.9L that typically likes to stall at idle after getting warm, though it has stalled once when going up a hill at near full throttle. At first, I thought it was a dirty throttle body, then the idle air control valve, then broken vacuum lines, then the TFI module. I've replaced/repaired all of these problems but none of them have worked. My current theory is dirty fuel injectors, which will hopefully be cleaned with seafoam, but any other ideas would be very welcome.

 

[fastpakr]

What things have you checked?
Fuel filter and fuel pressure
Timing with SPOUT disconnected
Engine codes
Etc

 

[Phroggy46]

I haven't gotten around to checking any of those things. I've mainly been going down the list of what might be the issue but I haven't been able to perform any thorough diagnostic tests yet.

 

[fastpakr]

I wouldn't replace anything else before doing some tests.

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[rusty ol ranger]

When it quits does it putted and die like its running out of fuel? Or does it act like you shut the key off?

Also, whats the process of getting it started again?

It could be nothing short of 1000 things. But it almost sounds like the ignition coil is bad. Espicially if you have to let it cool down to restart. But like fast said, do a bit of checking and let us know.

 

[rangerenthiusiast]

You might also want to check out 91Stranger’s “Truck Stalled While Driving” thread here:

http://www.therangerstation.com/forums/showthread.php?t=176400

His issue turned out to be a simple temp sensor...

EDIT - if you haven’t done little things like replacing the fuel filter, etc in a while, you could always start with those and just know they’re done for the future. Also, when I bought my ’92, I had a different problem (terrible vibration going down the road anytime it was under 3K) that wasn’t fixed by two cans of Seafoam. When I finally replaced the injectors, they were absolutely disgusting. I only bring it up so folks remember that really bad injectors won’t be helped by SF. If you end up having to replace them, shop around a bit. New ones for my truck were about 70 bucks a piece from my local auto parts store. I found a set of six rebuilt Bosch ones for $100 on eBay. A few days later, they were down to the last set and I got an offer to buy them for $70. Six for the price of one? Yes, please. Bought them and they work great.

 

[Phroggy46]

Update

Alright, so I finally got around to performing the fuel pressure test though I have yet to check the other things that fastpakr suggested. The fuel pressure test did yield some interesting results.

With key on engine off, my pressure was around 36/37 psi and didn't drop over 5 minutes

With the engine on, my pressure dropped to 30 and maintained pressure, even when revved. When I unplugged the pressure regulator vacuum tube, the pressure jumped back up to 40 and maintained pressure, also even when we revved it.


Rusty ol Ranger,
When it dies it acts as though the key turned off. I typically wait anywhere from 10 seconds to 5 minutes to turn it back on again and it usually is easier to turn on when it's moving vs. when I'm stopped at a light.

 

[cp2295]

Did you replace the TFI with a high quality unit? Cheap Chinese ones don’t hold up too well and your problem sounds exactly like a bad TFI. I’d recommend getting a motor craft part off rockauto.


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[Phroggy46]

Did you replace the TFI with a high quality unit? Cheap Chinese ones don’t hold up too well and your problem sounds exactly like a bad TFI. I’d recommend getting a motor craft part off rockauto.


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Yup I got a good one, and I still have my old one I think.