Hey guys, first post to this forum. I just bought what my wife calls a Whoopty truck, of course I know otherwise. 1991 Regular Cab Long bed F150 XLT Lariat with a 5.0 engine running dual exhaust. Anyways, the truck starts up and idles when cold. Once it warms up...it will dog out and shut down. I can attempt to start it but it wont fire and run. I put the throttle to the floor to engage the choke...it will fire, but not start.

I have changed the fuel filter, oil, new plugs, Coil, Distributer cap and rotor. I have also just dropped the front tank thinking maybe there was some bad gas from sitting too long. Guy I bought from said he used on a farm and it had sat for about 6 months. Just cant seem to figure out what the problem is. Any ideas on what to try next? Any ideas on what I can help rule out? Cant wait to prove the wife wrong...but towing it after it dies with my Ranger is giving more for the wife to roll her eyes about...if you know what I mean.

Thanks in advance for all ideas.

Chris
cwfrost34@hotmail.com

 

I had a very similar issue with my 91 Bronco 5.0. I was chasing constant codes despite the fact that all of the sensors had been replaced and it would still just die when it got warmed up. You MIGHT put a scanner on it and see what it tells you but you'll probably end up replacing the PCM like I ended up having to do. With mine, the chip board would get hot as the engine warmed up and would short out. When I replaced it, there was a visible burn spot on the board. Mine is in the passenger kick panel but I think yours is behind the glove box. Might wanna give it a look see.

 

sounds like you may have a bad ignition module on the distributor. when it warms up and it quits check for fuel and spark. you can also have autozone test the module. if it is the module then you'll have to make sure that it can be tested while its still hot otherwise they wont find anything wrong.

 

How many miles on the 5.0?