I have a 1993 F-150 with a 302 e.f.i. It`s all stock with 98,000 miles. Since about 20,000 miles it has developed a stumble. The stumble occurs when you accelerate after idling for anyting over approx 5 minutes.It feels like a large hesitation in the fuel delivery.If you shut off and re-start the engine before accelerating, it does not stumble(almost as if a sensor has been reset).After driving for a few minutes, everything is fine again until you sit idle again for several minutes.I`ve changed plugs,wires,cap,rotor and checked timing and if it was running hot,all was fine.Two dealers could find nothing wrong and the check engine light does not come on when this occurs. Also if you just stop for a light/stop sign breifly, it does not happen. Any help would be very appreciated. Thanks in advance.

 

Does your truck stumble when the engine is warm only? My truck does the same thing, only when the engine is warm though, when its cold it runs fine. I have no idea what it is, im gonna take it in next week. Cause im totally baffled. I get a differnt story from everyone. Fountain tire told me it was some module on my distributer.

 

Reelthief,have you checked or replaced your fuel filter?If not drain filter in a coffee can,after removal and see if there is any debris in filter.Good luck

 

 

Try these:

1. Fuel filter
2. EGR position sensor (EPS)
3. Throttle position sensor (TPS)
4. Engine Coolant Tempurature Sensor (ECT)

The EPS and TPS sensors are carbon film resistance type sensors. They are very prone to wearing out in one spot and causing the very stumble you're describing. I had a fuel injected Grand Marquis that I replaced both sensors twice by the time it got to 100K miles. The ECT is more of a long shot.


1999 XLT Supercab, V6 5-speed, Astro Eurolid II, MAAP Stainless Steel Nerf Bars, Mobil1.