99 GMC Jimmy fuel economy

drewcarr1drewcarr1 Member Posts: 2
edited April 2014 in GMC
I have a 99' GMC JIMMY with 150,000 mile. The milage has been crappy lately.I could drive about 5 miles and i can see a difference in the fuel guage. I had the dealership do the fuel injector service,I also had another mechanic change the o2 sensors since he said that would help the mileage.Is there any other part i can change to help my mileage. I know suv's burn more gas but i dont think i should be seeing a significant drop in my guage when i have only driven about 5 miles or so.


  • tidestertidester Member Posts: 10,059
    You may want to take a look at 2000 Jimmy/Envoy Fuel Gauge Problem or Blazer Jimmy Real World MPG.

    tidester, host
    SUVs and Smart Shopper
  • hughes70hughes70 Member Posts: 2
    I have a 01 GMC Jimmy recently changed the fuel pump and now it is misfiring. The check engine light is on, went and had code read and came up misfire on cylinder #5 . I have changed the plugs,wires, and distributor cap. Any other suggestions? code is po305
  • theyard1theyard1 Member Posts: 1
    I have the same code misfire on cylinder #5 took to shop thay told me it was my fuel presure reg leaking fuel into cylinder #5
  • hughes70hughes70 Member Posts: 2
    Mine didn't end up being fuel pressure reg leaking, it ended up being the intake manifold gasket. It is finally up and running no check engine lights or anything!! Thanks for your post though.
  • vince_27vince_27 Member Posts: 1
    My Jimmy has 153,000 miles on it. Lately it wont start. It will rollover but not fire up. After it rolls over, I turn off the key and it sounds like compression coming out of the air filter for a few seconds, and there is some smoke coming from the air filter? I kill the battery trying to start it? I have to jump it to get it to start. When it does start up there’s lots of black some coming from the tail pipe they last for about 5 seconds? Any ideas what could be going on?
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