95 GMC Jimmy hesitation, fuel gage jumping

[Sloppygolf]

I have taken my Jimmy to the dealer twice in the last two weeks. They first did the EGR kit, which made the service engine soon light go off, then replaced the idler arm.
This week they replaced the water pump (Leaking).
I reported a hesitation/cycling of RPM's while driving, especially in the 45 to 60 MPH range. They said it was a transmission problem.
So I left it at that for now.
However after getting it back yesterday, and driving it this morning, I noticed that the fuel gage also jumps from 1/4 full to above full especially when starting out from a stop. Could this indicate the real problem?? Maybe fuel filter, computer, etc???
Please help, taking a trip next month, want to get it right!!!!

Thanks

[96JimmySLE]

That's common. The sending unit uses a float and when you accelerate or come to a stop, the fuel will shift and cause the float to rise and fall. It's nothing to be concerned about.

[Sloppygolf]

But what about the hesitation while driving? RPM's cycle during all phases becoming more obvious when it heats up. Dealer says it is the transmission switching in and out of overdrive (it is an automatic). All I see and feel is a surging and dropping off during 45 to 60 mph especially, but even at idle I can feel it not running as smooth as it used to. It seems like the dealer would find a code, or a vacuum line loose or something, he just says its the transmission, and they only replace them, not work on them.

It has 101,000 miles, no big trouble before, mostly egr cleaning/replacing.

Is their story plausable?????
Thanks for reponding by the way.

[chembrad]

Have you popped your plenum and looked at the fuel injector? If there is uniform carbon deposits on both sides, then you don't have a leak at the injector or the fuel line. If you have one side clean, then that side has a problem: passenger side = leaking injector, driver side = leaking fuel lines.

[BlazerLT]

Originally Posted by 96JimmySLE

That's common. The sending unit uses a float and when you accelerate or come to a stop, the fuel will shift and cause the float to rise and fall. It's nothing to be concerned about.

No, it is not common for a gauge to go from 1/4 to over full.

Sounds like you are having some fuel problems and your sending unit and pump are about to go.