have a 99 f-350 with the 5.4l engine surges at idle but you give it fuel it quits,changed all sensors and still surges

 

im having the same type of problem with my 2004 F350 with a 5.4. heres a link to it im still trying...
https://www.ford-trucks.com/forums/1...ith-5-4-a.html

 

have you checked your fuel pressure from pump?

 

Maybe your throttle position sensor is whacky.

 

done replaced tps and cleaned all of intake

 

IT DRIVING ME NUTS WITH IT IN GEAR IT FEELS LIKE THE ENGINE IS CAMMED BUT AS SOON AS YOU GIVE IT A LITTLE FUEL IT STOPS SURGING AND RUNS FINE

 

Maybe IAC valve?

 

REPLACED IT TWICE ONCE WITH AFTERMARKET AND THEN WITH FORD STILL NO CHANGE

 

THE ONLY THING I HAVENT CHANGED IS THE PCM

 

sticky pcv valve?

 

Have you cleaned your throttle body good with carb cleaner?

 

I know this is an old post, but it sounds like the EGR valve.
When it is open at idle it will cause the engine to surge like it has a cam and you will smell gas and there will be a knocking from the engine if it sets long enough. The knocking is the fuel exploding before it should as the surge of the RPMs and if bad enough the engine will stall. If you give it gas it will run correctly almost, but then you will see the unburnt gas fumes like your engine is smoking in a garage if parked. You will smell that gas burnt fumes also as they will be really strong. It may not be fully clogged yet, but it will happen more as you drive it and your fuel will burn more of it. When you come to a stop it will start surging more and can stall the engine out. You can clean them out and I would say find out how by watching a video on youtube. A new one for a 4.6/5.4 is around $100.00 at a parts house.