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2003 Chevy truck

Printed From: Unofficial Allis
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Forum Name: Shops, Barns, Varmints, and Trucks
Forum Description: anything you want to talk about except politics
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=167944
Printed Date: 14 Nov 2024 at 12:37am
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Topic: 2003 Chevy truck

Posted By: Ryan Renko
Subject: 2003 Chevy truck
Date Posted: 01 Feb 2020 at 8:06pm

I have a 2003 Chevy work truck with the 4.3 engine. It runs like a champ but about once a week it will develop a issue where the motor will stutter and stammer and the check engine light will flash but not be steadily on. After about ten seconds all will be well again. I want to correct this issue but when I plug in my code scanner it doesn't read any active codes. How can I find out what this once a week flashing but never constant engine code is? Thanks in advance, Ryan

Replies:

Posted By: shameless dude
Date Posted: 01 Feb 2020 at 10:58pm

sounds like a loose connection on the puter somewhere, may hafta start wiggling some wires?

Posted By: desertjoe
Date Posted: 02 Feb 2020 at 1:55am

Them friggin GM's are notorious for havin issues with loose ground wires and the hardest to find,,,,!! After I retired from the refinery,, the owner of the local GM dealer asked me to go help them at the Service dept and I think that was one of the biggest complaints we were always workin on on the older GM cars and trks.. We had this one long timer tech that was the best at finding them loose ground wires,,,so like ole Shameless says,,start engine turn on lights and start pushin pullin wires, a lot of them had a ground wire loom right behind the left side of engine and almost impossible to reach,,,Good Luck,,!!

Posted By: sho-man1
Date Posted: 02 Feb 2020 at 8:09am

Does it show this upon startup or driving around town or on the highway?

Son's 2002 GMC with the 4.3 had #5 misfire all the time. We checked fuel pump, fuel pressure, pressurized fuel system leak down test, cylinder pressure check and leak down test. new spark plugs and wires, new distributor. Just about everything verified good or replaced. only thing we did not check was valve springs...sold truck...Buddy with a suburban v8 would get a random misfire and stutter when driving into a 20-25 mph headwind...even had a service manager drive a few days and damn'd if it did it to him while driving into a string headwind...he thought it was distributor( nope).

We called it the "Casper Caper" ghost showed up throw a code then disappear...

Posted By: darrel in ND
Date Posted: 02 Feb 2020 at 8:24am

Try running some sea foam in the gas for quite a few tanks full. Don't worry about putting too much in. Whenever my suburban starts acting up like that, that's what I do. If i remember, I just put a couple cans full in about every third tank full. If I forget, it reminds me, by acting just like you described. My burb has the 8.1 in it though. Maybe that makes a difference. Darrel

Posted By: HD6GTOM
Date Posted: 02 Feb 2020 at 9:59am

Have you replaced the cap and rotor lately? Mine would get to running rough, power would drop off. Replace cap and rotor with quality cap and rotor from NAPA would fix the problem.