Engine Surging...but why?

[ACerf]

I have noticed lately that the engine is surging. I only appears to do when I am in drive. . like waiting at a traffic light. If I put it in netural it appears to stop. It doesn't always do it, which really puzzles me.

Thanks for the help!!

 

[JCleary]

Could be due to cold weather. The heater grid will cycle on and off at low speed or at a stop when it's really cold. It draws enough to cause a variation in the idle. This has been my experience with my HO 6 speed.

 

[Loaded 45]

Possibly your Edge ez - The 2 differant ones I had both caused surging & gets worse over time. Disconnect it and see if the surging stops.

 

[Buzzer]

A failing lift pump also includes those symptoms.

 

[BHaner]

Mine does the same thing. I have taken all the boxes off and it still does it. It is the worst when it is cold out in the mornings and it hits 1k RPM on startup.



I also get the surge when cold under low throttle pressure when driving. That's fun with a stick! Yeee Haw! :-laf



I have been told that the fuel rail pressure control valve can do this when it starts to stick. I was also told that using a fuel adative will mask it. I have not tried it yet.

 

[ACerf]

I don't like the thought of thinking it is a fuel pump! I have noticed that it hasn't been doing the last couple of days. We are wintering in Az. so it doesn't get quite as cold as SD!

 

[LightmanE300]

If the surging were the heater grids, you'd see the voltmeter drop with the surges. That also doesn't happen when the engine is warmed up. I have a similar surge/vibration at times when it's really cold out. I have always kinda thought it was my exhaust system. At one point it got bad, and then I had a broken hanger on my tailpipe. I replaced it, and the sound went away for a while. Now it's back on occasion. I recently drove to FL , and the entire time I was there in warm temps I had no surge or noise. Who knows. I've decided I spend entirely too much time listening and paying attention to how this truck runs and am going to try to spend more time driving it and cranking the tunes.