Good idea gone bad...2002 Chevy Sierra PU

Bought the truck at auction last November, drove it to my mechanic and that’s the last time I drove it. It’s a 1500 series, with 139,000 on a 4.3 Vortex, W-engine.

It has had all the basic computer tests, compression good. It misfires and overfuels on drivers bank, plugs gone black. Changed 02 primary and secondary.

Still no change. Now trying to find schematics to help the mechanic. I have spent almost all my savings and have no truck. I am pretty sad.


Is there a question? Seems that your mechanic is on the ground, and trying. So, what is the point, here?

He should know how to obtain a shop manual. You could always try a Haynes manual. $15.00 at any auto parts store. They have schematics.

Misfiring and is flooding. Possible faulty fuel regulator and or coils.

I’m wondering why both O2 sensors were changed? Any codes? If so, what were they?

I guess he is now stuck with replacing all the related wiring.

Thanks for the reply. I realize I should have written a Silverado not Sierra…at any rate, it’s a PU. I will get the Haynes manual. I appreciate your help.

Ran a car facts today and back in 128,000. the compression check was good. Which kind of makes me wonder what happened since that time. I have another mechanic who is getting the specs for the motor type sometime this week.
What a hell of a job. Thanks for the reply

Is your mechanic your boyfriend or relative? Competent mechanics usually have full access to these items by subscription using an internet or DVD/CD system.

It sound like you need a new mechanic.