zepplinc20
Newbie
- Joined
- Jul 31, 2015
- Messages
- 3
- Reaction score
- 1
Hey guys I'm looking for a little direction on this one. I recently purchased a 90 k3500 with 99k miles. This thing runs like dog crap. It's extremely rich and has a slightly rough idle. I've gone through the typical tbi stuff like cts, map, egr...etc. TBI was rebuilt and pressure regulator looked good. I'm waiting on the adapter for a fuel pressure test. All that being said, I've got a hunch there is something going on with the valvetrain. Either timing chain, camshaft, or burnt valve. Timing was verified to be 4 degrees btdc. Also has a slight miss when cold I believe from being so rich.
Every once in a while immediately after shifting and letting the clutch out the thing will buck like crazy until I push the clutch back in and let it out with a gentile application of the gas pedal. Also a few times I've noticed a backfire through the intake. One time that comes to mind was while towing a camper, accelerating up a 6 degree grade from a dead stop.
My question is where to go from here? I have a leakdown tester, and a compression tester. Which one first? I though I might start by rotating by hand and checking the distributor for play to eliminate the timing chain. This type of diagnosis is new to me so I'm all ears. Sorry for the long post.
Every once in a while immediately after shifting and letting the clutch out the thing will buck like crazy until I push the clutch back in and let it out with a gentile application of the gas pedal. Also a few times I've noticed a backfire through the intake. One time that comes to mind was while towing a camper, accelerating up a 6 degree grade from a dead stop.
My question is where to go from here? I have a leakdown tester, and a compression tester. Which one first? I though I might start by rotating by hand and checking the distributor for play to eliminate the timing chain. This type of diagnosis is new to me so I'm all ears. Sorry for the long post.
Last edited: