General Tech Good at troubleshooting? Have a non-specific issue? Discuss general tech topics here. IF YOUR QUESTION IS SPECIFIC TO A CERTAIN MODEL, IT DOES NOT GO IN THIS SECTION.

4.3 issue

Old May 16th, 2019, 12:17 PM
CF Beginner
Thread Starter
Join Date: May 2019
Posts: 2
Default 4.3 issue

Thanks in advance for the help.

Recently bought a vehicle with a 4.3 tbi in it. Has mild cam.

Starts and idled well but hesitant and poor power under load.

Previous owner stated : ran excellenf until out mudding and blasted through a mud hole. Ever since then ran crappy
Took it home checked a bunch of things
Good compression
Good fuel pressure
Good map
Nonsign of spark arcing
Fuel spray pattern looks good
Pull plug wires one by one while running, same rpm drop for all. Seem equal, no dead cylinder.

Ok now the weird part
Checked timing (yes properly disconnecting timing wire) and found it to be a bit retarded. Advanced to correct spec run a bit better but still poor.
Continued advancing time until it runs nearly normal. Approximately 20 initial now. Starts and runs and accelerates good now.

Though 20 initial seems very excessive.

My thought is that he over revved it playing in the mud and skipped a toogh on the cam timing.
Likely to have crappy nylon timing gear

Only runs decent with way advanced intilal timing.
Ran fine until playing running it hard.

Thanks for the ideas

Last edited by 4.3jet; May 16th, 2019 at 12:22 PM.
4.3jet is offline  
Old May 16th, 2019, 1:53 PM
I'm here for the party
Irish_alley's Avatar
Join Date: Feb 2019
Location: Maryland
Posts: 568

it does sound like something has slipped. but what year 4.3 are you working on?
Irish_alley is offline  
Old May 16th, 2019, 6:54 PM
CF Beginner
Thread Starter
Join Date: May 2019
Posts: 2

TBI 4.3
4.3jet is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: