Hi i have a 1989 F150 6/300 thats developed a stumble just off idle as you accelorate from low idle,ie at intersection etc, im wondereing is anyones come across it before i start pulling things apart or replacing plugs leads etc it runs fine except for that.
cheers Baz.

 

Good morning...

Introduction Forum, Introduce yourself to the Community here! If you have a technical question, try posting it in the appropriate forum.

Try reposting your questions in the Pre 1997 F-150 Forum for your answer...

Good luck

 

 

Welcome!

 

Welcome!

 

1. I would check all ignition components and replace as needed.
2. Replace fuel filter if more than 2 years old.
3. Pull O2 sensor and check for contamination.
4. Check fuel pressure at FPR.
5. Check the ACT and ECT sensors, as they are fouled.
6. Clean throttle bodies.
7. Clean IAC and EGR valves.

James

 

Thanks James, havnt had much experience with fuel injection, i do know where the O2 sensor and EGR valve is but no idea about the rest can you explain please? cheers Baz (old school carb man lol)

 

The ACT, ECT, MAP, O2 and TPS are all part of the Speed Density (non Mass Air Flow) system. Each sensor works together to regulate air, fuel, throttle position and so on.

I would look at a Haynes manual or pull up the parts at www.rockauto.com to see what the components look like. The ACT, ECT, MAP and TPS are underhood.