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General => Lounge => Topic started by: shame302 on March 01, 2005, 04:38:45 PM

Title: s10 PU V6....cant fix bucking, please help
Post by: shame302 on March 01, 2005, 04:38:45 PM
vortech v6 s10 pick up. just did new cap, rotor, plugs wires, and fuel filter. nothing helped. figured it was an ignition problem.

the truck bucks when driving or under a load. idles fine though. feathering the throttle sometimes smothes it out. wher too look next? any ideas...thanks, john
Title: Re: s10 PU V6....cant fix bucking, please help
Post by: Cougar8775 on March 01, 2005, 04:42:56 PM
check all the vacume lines on it and check the map sensor. on gm's if those go bad or has a bad vacume leak it could cause that problem.
Title: Re: s10 PU V6....cant fix bucking, please help
Post by: Haystack on March 01, 2005, 04:45:11 PM
I would check erg and such
Title: Re: s10 PU V6....cant fix bucking, please help
Post by: shame302 on March 01, 2005, 04:46:46 PM
alright thanks...ill go take a look...thanks again...
Title: Re: s10 PU V6....cant fix bucking, please help
Post by: Thunder Chicken on March 01, 2005, 07:32:15 PM
I'ma gonna guess this is an older Vortec, the one with CPFI (Central Port Fuel Injection). Those injection systems consist of a central electronic fuel injector located inside the intake manifold, with plastic tubes running to individual "poppet" valves where a real port fuel injection system would have injectors. The injector/lines/poppet valves resemble a spider.

This system is notorious for those poppet valves plugging up or sticking. The only cure, other than to take the upper manifold off and clean the valves individually, is to have a professional injector/EFI system cleaning done. Not a can of STP, either - a real, honest-to-goodness, connect-a-can-of-cleaner-to-the-fuel-line injector cleaning. This usually clears it up, unless the poppet valves are toast.
Title: Re: s10 PU V6....cant fix bucking, please help
Post by: shame302 on March 02, 2005, 12:44:14 AM
well, my buddy decided to take it too a mechanic after all. thatll teach him to buy a chevy...im curious too see what its going to end up being. thanks guys, i appreciate the help
Title: Re: s10 PU V6....cant fix bucking, please help
Post by: DryGoods on March 06, 2005, 10:28:22 PM
That happened to my 2nd previous company van, an Astro with a Vortec V6.  The CPI needed replacing, and the problem was solved.
Title: Re: s10 PU V6....cant fix bucking, please help
Post by: shame302 on March 06, 2005, 10:46:20 PM
Quote
That happened to my 2nd previous company van, an Astro with a Vortec V6. The CPI needed replacing, and the problem was solved.


thi injector itself? just curious. havnt heard fron the guy with the truck yet.
Title: Re: s10 PU V6....cant fix bucking, please help
Post by: DryGoods on March 07, 2005, 07:07:18 PM
It came as the whole injector unit, was pricey too as i recall, it was my 1995 company van with the 4.3.  Gas mileage improved afterwards by quite a bit too.
Title: Re: s10 PU V6....cant fix bucking, please help
Post by: foxford on March 08, 2005, 08:49:24 AM
Simple solution, take it to the junkyard so "like a rock" it can sit there. Seriously though, I would check fuel pressure to make sure there's no clogs, and like thunderchicken said, have the injectors cleaned the right way. I bought a car on the cheap that wouldn't even idle(mark VII), cleaned the injectors, and that 220,000 mile 5.0 HO ran like a brand new motor, even registering lower emmisions than my mom's '95 Regal grand sport(this was in '97)