I have a 99 F-250 V10 that when in drive as soon as you step on the gas it bucks and sputters and then dies. It will start and idle but as soon as you put in gear and apply gas this happens. Had someone look at it and told me it wasn't getting enough gas and we replaced fuel filter and pump but it is doing same thing. When idling before fuel pump replacement if you rev to 1500 rpm it would die also. Any Suggestions would sure help. Thanks

 

Also forgot to mention if it sits overnight it will start right up and you can drive around the block before it starts doing it. Once it starts doing it as soon as you apply gas the rpm's jump up and down and dies. It will idle just fine but as soon as in drive and apply gas this happens. Canot drive it far enough to get anywhere.

 

Suggestion: Might try and check for codes? Report back...


biz

 

fuel pump or fuel filter ???

 

He replaced those already.

Throttle position sensor?

Does it do it in reverse?

 

MAF sensor or the Oxygen sensor? Just a guess as it runs fine until it warms up.

 

Sounds more like a MAF issue. If it were me, I'd hook it up to my Autotap and see if the MAF flow numbers are reasonable.

Sounds like when it's in open loop, it's fine, but when it goes to closed loop (which happens pretty quickly with the V10) it falls on it's face.

Pull the air box apart and see if the MAF is either very dirty or a leaf or some other debris has covered the MAF filaments.

Either that, or you have a big vacuum leak between the throttle body and the MAF.

 

Ok- connected OBDII and got four readings which led me to replace two coil packs that were not sparking. I went ahead and replaced all spark plugs as well. I restarted truck and cleared the OBD and truck still did the same thing. Reconnected the OBD and recieved a code P0320. Anybody out there know what that would be. Also checked MAF and it appeared clean and ok. Thanks

 

Did a search...and found that P0320 is mostly related to a bad crankshaft position sensor (CPS).

At FORDPARTSGUY.com that part is about $26.45.

Hope this helps...


biz