Surging

[Leaflet]

6.2 diesel 2 w/d Suburban silverado. Hello everyone. Its been a while since rebuilding the steering, the brakes,the steering wheel shaft,and both heads but motoring is such a pleasure. I am getting occasional surging at low revs - effectively she really takes off and you have to be very light on the accelerator and then she calms down. Tick over is ok, cruising is ok at about 90 (not really legal here in the UK) so it is just around town that this surging is noticable.

Any ideas where to look first - or not to worry!

[Subzilla]

Always go for the cheapest and easiest first - try the fuel filter. Then the fuel pump?!?

[gavio]

I just had a very similar problem - over a little time it degenerated to where it was undriveable - throttle would run away by 1500 RPM or so.

I took apart the fuel system in about six different places til I found out it was in my filter. I had originally ruled out a filter because I had just changed it less than a thousand miles earlier. And additionally, it had behaved very differently when the filter had been dirty before. All I can figure is that I got some bad fuel or something (this was on the fuel side of my system and not connected with the veggie oil side at all) and it messed up my new filter.

I'm now solidly down with the above advice - ALWAYS check your filter first in these cases.

Good luck!

[HANK1948]

I am having this same problem as you and replaced the fuel filter the lift pump and still the same problem, and found that there is air in the lines , havent found the air leak yet ,I believe its rusted lines off the tank. I found there was air in the line by installing clear hose inline between the line coming from the tank to the fuel pump and sure enough you can see the air in the line while is running give it a try its simple and cheap way to diaignose.

[Leaflet]

The majority opinion seems to be the fuel filter so I'll start there - thanks

[Leaflet]

You guys know your engine - following a complete breakdown it was the fuel filter. Changed it and off we go again. Thanks for your advice it sved me hours of looking at the wrong thing.