1988 f 150 4x4 shuts off

[bollweevil]

I have a 1988 f150 4x4 that will run for about 25 minuntes idleing or you can drive it about 5 miles and it will shut off. tow it home and it may start up or you may have to wait an hour or two. i have changed distributor, module, stater and checked everything electrical. i can hear the fuel pump running when i switch the key on. I am not sure now if it is a fuel pressure problem or what. I was hoping that someone in here has had this same problem. any help?

[rockwood84]

what size motor?

[JDFFMechanic]

I am having the same problem with a 1988 F150 with 5.0 (302) automatic 2WD. Change of coil and EGR valve yielded no results, along with a full tune-up, including the usual plugs, wires, cap, rotor, fuel filter, air filter, and PCV valve. PCV line is still in good shape, cannot locate a vacuum leak, and fuel pressure from both fuel pumps seem to be pressurizing fine (dual tank system). I am leaning toward a possible intermittent electrical open to the pumps or the transfer valve, or both. I will try with a longer hose on the fuel pressure gauge to see if I can see a drop when it does die. Also, I have found an issue that I did not know about. Apparently, two years of the EEC-IV diag system will not communicate (model specific?) with the usual EEC-IV compatible OBD-1 tool. Any ideas? I will post a solution if I find it before then. Thanks!!

[JDFFMechanic]

Think I just found the solution to mine, but time will tell, since it seems to be intermittent. The ignition module on the side of the distributor seems to be a common cause of this. When it cools down, it starts running again. Pull the module off and take to the local Advance Auto Parts, and they will test for free. You will need the Ford ignition module wrench, as a socket that will fit the heads of the screws will not fit in the holes of the module...