Surging ? Help!

[walter.dreyer]

Got the truck back from the stealer yesterday, everything semed to be fine. Started the truck up this morning, was five degrees outside. I have powerservice in the tank, and the truck was plugged in all night. While it was warming up the missus and I both noticed it was surging. Now I've read alot about fords surging, but I never heard my truck sound like this before. It used to be that you could hear the turbo windup then slow down while it was idling, but it had no noticeable RPM change. I thought this is what everyone was talking about. Now there is a very noticeable RPM change going on ( as evidenced by even the missus taking notice). Is there something likely still wrong, or is it finally operating correctly. They replaced both oil pumps, the high pressure fuel pump, the fuel pressure regulator, and the fuel pressure sensor. By the way my warranty is up in early March, so if something is not right, I need to get it fixed now!

 

[bushpilot]

could just be the cold air....did it stop once the truck is warmed up ?
does it do it going down the road @ steady throttle (flat road) ?

 

[Kleetus]

How many RPM is the tach showing the change to be?

 

[keanoknick]

Was it just idleing to warmup when it did this? IF so it is proabably just the ECM ramping up the throttle a bit to help warm up the engine, mine does that frequently.

 

[walter.dreyer]

Actually it only did it that morning.Yes, it was warming up, and once I started driving it didn't do it any more. I don't know what the RPM jump was since I was in the house while it warmed. Could air still in the fuel system, have been what was causing it. I only live about 5 miles from the stealer. Max speed 45 mph. It didn't do it the next morning, and it was just as cold. In fact it hasn't done it since. I drive 22 miles one way to work, so I had driven at least 44 miles, mostly highway, by the next day.

 

[keanoknick]

Proabably just the ECM ramping up the throttle to help warm the engine up faster, I wouldn't worry to much about it. Was it colder that morning than normal?

 

[Moe-B]

If it revved up and maintained the higher RPM then it's normal. Next time it does it, get in and tap the brake pedal. If the RPM drops down it's the ECM.

 

[walter.dreyer]

I'll make sure I do that if it happens again. However, the RPMs were noticeably rising and falling, to the extent that my wife even noticed, and she asked me what was going on. Once I got in and started driving down the road everything was fine.