f150

Ok here it goes. I have a 86 5.0 in a Lincon Town car and I can't figure this one out. When the car runs for around 30 mins or so it just dies. It starts off jumping in and out gear then cuts off. I can crank it back up and it will run for a sec then cuts back off again. After the car cools off for a couple of hrs it runs great for another 30 mins or so then does the same thing. I changed the control module, ignition coil, and the cap and rotor. I checked the fire and fuel and that seems to be fine. I have had a few of 5.0's in my time but I have never seen this happen. So any ideas or tips I could get from you guys would help.

shaners90lxhatch

tough call. If you checked fuel and spark after it had cooled and was running- no dice. If it has fuel and spark when it wont run, you must have a backpressure issue. I stand by ether. If she will run if you keep your foot in it - she is starving for air (iac is trash or backpressure is onsetting). If she will run on ether - loosing fuel pressure or injector pulse. But if it wont run on ether, you have crap for spark.

f150

fuel and spark was checked when it would not crank and when it starts that crap you can hit the gas to try to keep it running but it still cuts off

shaners90lxhatch

What do you mean it "jumps in and out of gear"? Is it a total pooch before this stall occurs? If it lacks power, your exhuast may be plugged. PCM failure is rather uncommon (moreso with the newer pcm's) but it is a possibility. If you truly have good fuel and spark the pcm is pretty much doing it's job. Your spark should be able to jump an inch gap. How did you check for fuel? Ether man, it's the best way to check.