I have a 2001 f150 with a 5.4 v8. I have taken into the Ford dealership 4 times with this problem. When I start the truck, ususlly in cool weather, the truck sounds like it's going to start but doesn't. I turn the key againg and the engine sort of "chokes" and the rpm's don't jump up like they usually do when you start any vehicle.

I have had the fuel pump replaced, a part called the fuel relay switch replaced and the idle air control valve replaced and it still does it. Does anybody with some automotive knowledge know what the problem may be. This dates back to February 2002 for me and after the weather turned warm I didn't have the problem all summer. But just this morning the truck did it again because it was around 60 degrees. Any feedback would be appreciated.

 

Sounds like the dealership hasn't thrown enough parts at it yet. If I wanted to go the hap hazard route I would throw a TPS sensor at it next for grins. You can't effectively substitute a "good known part" on a system like this. Eventually you will happen accross the probelm and have an almost entire new vehicle along with it.

The vehicle will likely have to have the probelm at the time that they look at it. Its hard to say what the problem is unless you go through a process of diagnosis. For example, if they tested the fuel pressure at the time and it was sufficient, there is no need to replace the fuel pump. If the fuel pressure is insufficient, there are several possible culprits that CAN be determined with a diagnosis process. The idle air control valve simply controls how much air enters the engine when no pressure is applied to the gas pedal. If it were open all the way the engine should start (or at least act like it wants to). If it were stuck closed, applying light pressure to the gas pedal would allow air to enter and the engine to likely start.

Basically the dealership isn't diagnosing the problem, either because it is not occuring when you bring it in, or because they are idiots. Make sure that the problem is occuring by leaving it at the dealership overnight and meeting them in the morning to try and start it (or some other way of inducing the problem). If they have had the vehicle with the problem occuring at the time for 4x now, find another servicer.