Problem started back when the weather was cold. I would start the engine, the engine would start normally and would idle perfect, fast idle would kick down like it was supposed to. However, when the engine warms (not specific Temp), the idle would turn ruff, (no CHECK ENGINE light). When I disconnected the vacuum line on the EEGR valve, idle would smooth to normal, so I thought a bad EGR valve, replaced it, same problem, replaced the Sensor on top of EGR valve, same problem, replaced oxygen sensor in exhaust, same problem. Now the weather has warmed and when I start truck it idles normal for just a few seconds before ruff idle, so I am thinking I have a sensor the has something to do with ambient temperature or intake temp. Can anyone help me with this one? The truck is a 1994 F150 Supercab 4X4 longbed with 302 V8. How many more sensors are there and where are they located? Thanks a bunch, Mike

 

Try cleaning the elements inside your MAF sensor.

 

where is the MAF (Mass Airflow Sensor) located on my 1994 F150 4x4 5.0 EFI V8.