Hello all, I have an 87 F-150 with a 302. I have put a lot of money in this truck and still can't find any answers. When i crank her up, she will run like a sewing machine. Once she warms up, +/- 15 minutes, it will shut down. After it shuts down, you can try all day long to crank it and it will not restart until you turn the key all the way off and only then will it crank. It will crank on the first try as long as you turn it all the way off, she'll run for about 5 minutes an the shut off again. I have replaced the fuel pump, fuel filter, fuel pump relay, ignition switch, ignition control mod., cap, plugs, rotor, wires, button, and idle air control valve. I spent $680.00 at a shop for this problem last week, and they couldn't figure it out. I sure would appreciate any help. Thanks, Chris

 

pull codes, check for vacuum leaks, test fuel pressure, check timing with the engine warm and spout connector removed.

 

I'll check The vacuum lines. The only codes I'm getting are 12 and 13, according to the mechanic these are high idle warning and a low idle warning. Something like that. I made sure the idle was at 10% with the spout removed just before it shut off, That was fine. And the mechanic checked the fuel pressure, it was 40 before cranking and 30 at idle. I have tried just about everything I can think of to no avail. That's why I'm open to all ideas. I've easily sunk $4000 in this truck. It's driving me crazy. Thanks for the insight. I'll definitely check the vacuum system tomorrow.

 

well 30 at idle is to low. it should be closer to the 40psi all the time. I also dont understand what you mean by the idle being at 10% at idle.

the timing should be at 10* btdc with spout connector removed. does it appear the idle screw on the throttle body has been tampered with by chance? If so that could be a problem as that is a factory set item that should never be touched.

 

Since i got the information on the fuel pressure, i decided to change the fuel pump, filter, and relay, just in case. I haven't rechecked the fuel pressure yet. As for the 10%, on the harmonic balancer, I set the timing to the 10 with the spout removed. I plan on looking at some things this weekend such as fuel pressure, vacuum, Etc. Ill re post probably Saturday after i get some results. Thank you.

 

which 10? there is ATC and BTDC, need to make sure your using the correct mark.

 

Sounds like the same problem I had , was PIP sensor in distributor