Slight hesitation in idle 2003 gmc

Ninja_Lawn_Guy · 11-01-2009, 10:15 AM

Just assuming it's a dirty fuel filter, but what other things should I check? I change the filter pretty regularly....

I have cleaned the k&n setup and the mass air flow sensor, replaced the pvc that was stuck and cruddy, Already have new wires and plugs, hand cleaned as far down the throttle body as I could, really shiny now, and used some complete fuel system cleaner with 98 oct gas.
My other thought is it has something to do with the calibration of the ecu after I removed the cats, back pressure not enough..kinda been like this for a little while, still runs like a beast, but just a slight shutter...more noticable as of lately.

bradrhale · 11-01-2009, 07:32 PM

did you remove the TB or just stick a toothbrush down its throat. it is nothing to take one off and this will be much more affective than doing it mounted. do you normally run a fuel injector cleaner?? i try to use a cleaner in a tank once ever couple of months. i dont know if it works but i dont have problems with idle. coincidence?? cant say but i do stick with what works.

Ninja_Lawn_Guy · 11-02-2009, 01:17 PM

Tooth brush...Didn't want to take anything apart ...but I could...imagine it's pretty funky in there
Yes on the injector cleaner, I nornally premium gas with octane booster, and I put in concentrated injector cleaner about every 1500 miles if not one per oil change. Seems like it's more noticeable when it's warmed up...I'm doing a coolant flush before the snow hits.

bradrhale · 11-02-2009, 02:48 PM

injector cleaner is not going to help the throttle body out none. you have MPFI. i promise that it is not hard to remove the TB unless you end up like me where someone has broken off the tab that removes the cables onto the side. if it werent for that, it would have taken me a whole 5 mins to remove it.

Ninja_Lawn_Guy · 11-19-2009, 07:18 PM

It was the throttle body cleaning or the new gas filter or both...thanks..

11-01-2009, 10:15 AM	#1
Ninja_Lawn_Guy Senior Member Join Date: May 2008 Location: Michigan Posts: 413	Slight hesitation in idle 2003 gmc Just assuming it's a dirty fuel filter, but what other things should I check? I change the filter pretty regularly.... I have cleaned the k&n setup and the mass air flow sensor, replaced the pvc that was stuck and cruddy, Already have new wires and plugs, hand cleaned as far down the throttle body as I could, really shiny now, and used some complete fuel system cleaner with 98 oct gas. My other thought is it has something to do with the calibration of the ecu after I removed the cats, back pressure not enough..kinda been like this for a little while, still runs like a beast, but just a slight shutter...more noticable as of lately. Last edited by Ninja_Lawn_Guy; 11-01-2009 at 01:43 PM.

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11-01-2009, 07:32 PM	#2
bradrhale Senior Moderator Join Date: Apr 2006 Location: Texas Posts: 8,025	did you remove the TB or just stick a toothbrush down its throat. it is nothing to take one off and this will be much more affective than doing it mounted. do you normally run a fuel injector cleaner?? i try to use a cleaner in a tank once ever couple of months. i dont know if it works but i dont have problems with idle. coincidence?? cant say but i do stick with what works.

11-02-2009, 01:17 PM	#3
Ninja_Lawn_Guy Senior Member Join Date: May 2008 Location: Michigan Posts: 413	Tooth brush...Didn't want to take anything apart ...but I could...imagine it's pretty funky in there Yes on the injector cleaner, I nornally premium gas with octane booster, and I put in concentrated injector cleaner about every 1500 miles if not one per oil change. Seems like it's more noticeable when it's warmed up...I'm doing a coolant flush before the snow hits.

11-02-2009, 02:48 PM	#4
bradrhale Senior Moderator Join Date: Apr 2006 Location: Texas Posts: 8,025	injector cleaner is not going to help the throttle body out none. you have MPFI. i promise that it is not hard to remove the TB unless you end up like me where someone has broken off the tab that removes the cables onto the side. if it werent for that, it would have taken me a whole 5 mins to remove it.

11-19-2009, 07:18 PM	#5
Ninja_Lawn_Guy Senior Member Join Date: May 2008 Location: Michigan Posts: 413	It was the throttle body cleaning or the new gas filter or both...thanks..