I have a 1986 Ford F150 lariat with a 5.0L engine that has electronic fuel injection. The truck is in gorgeous shape with 77,000 original miles. It has duel tanks that I replaced both tanks and fuel pumps and switching valve.

I have a problem that the engine stalls. Have had the Idle Air Control Valve Replaced and this seemed to work for about a week. Now its gone back to stalling again. I don't think that the new valve is bad. I was wondering if it could be a bad MAP sensor or Throttle Position sensor or maybe even the Heated O2 sensor. Any opinions would be greatly appreciated.

I have stage 2 lung cancer and would like to get this running really good before I cant work because of treatments.

Thanks

 

Use a vacuum gauge to monitor engine vacuum. Refer to the instruction sheet or a repair manual to understand what the gauge readings indicate. If your instrument cluster has a check engine light, you can check for onboard diagnostic codes. Cycling the ignition key to start and back to of off, then back to start at least 3 times will start the diagnostics sequence. Count the check engine light flashes, then there will be a pause and then more flashes..... count these flashes too. The light will continue to flash codes if more than one code is stored in the computer memory.