Sooo, as the title says I'm encountering an engine chug at around 30-35mph...

I've slowly been doing work to try and show some TLC to this baby that has been severely lacking.

The engine chugs if I let off the gas around 30-35 for a brief few seconds. Under load/rev it runs just fine through that speed without a hickup, it's just when I let off the gas around that range.

Any suggestions? I'm not sure where to begin with this one.

 

I was thinking it might be something to do with fuel filters, haven't done any fuel system clean up yet. Input?

 

*bump* any suggestions? this one is boggling me where to even begin trouble-shooting..

 

Ramblin ****** Commandments of Poor Running Truck
1. DO NOT GUESS. DIAGNOSE. SAVES BIG DOLLARS.
2. Pull Codes.
2. Get a shop manual. I use Haynes. The haynes has good trouble shooting/diagnostics and fix procedures.
3. Inspect the basics and replace if necessary like plugs, wires, cap, fuel filter etc..
4. Sea Foam procedure. This procedure does wonders. It can make a difference between a truck that shakes like Kathryn Hepburn did and one that runs smooth as silk.
There's no easy fix. Your truck could be running poorly because of something simple like a bad plug, sloppy timing chain or any number of things.

Good Luck!
*****.

 

Thanks for the reply. Yeah I've got a Chilton's, will pickup a Haynes too if necessary. I've already done the plugs/wires/cap. Replaced the plugs, wire and cap were actually good. Haven't checked fuel filter yet, so that'll be the next.

Also sea foam procedure makes that big of a difference? I'll definitely have to look into it then...