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tim_mc · 08-04-2022, 07:47 AM

Sounds similar to my issue last year: Truck had an occasional backfire or load up when driving. It progressively got worse to where it would start OK, but would die when put into gear. It would idle and rev OK, but ran badly under a load, or when stopping at a stoplight. I had to put it in neutral a few times to keep it from dying at intersections. Later it would lean out and backfire after it warmed up and eventually would not restart when warm.
Fix: New coil and module. GM HEI was only a few years old, but as we know that doesn't matter. Upgraded to DUI coil and module and have been running great since.

08-04-2022, 07:47 AM	#28
tim_mc Registered User Join Date: Jan 2019 Location: St Peters, MO Posts: 434	Re: 1968 GMC 250 Inline 6 4.1L Chugging Sounds similar to my issue last year: Truck had an occasional backfire or load up when driving. It progressively got worse to where it would start OK, but would die when put into gear. It would idle and rev OK, but ran badly under a load, or when stopping at a stoplight. I had to put it in neutral a few times to keep it from dying at intersections. Later it would lean out and backfire after it warmed up and eventually would not restart when warm. Fix: New coil and module. GM HEI was only a few years old, but as we know that doesn't matter. Upgraded to DUI coil and module and have been running great since. __________________ 1967 C20, 350 SBC w/Comp roller cam, 700R4 w/3.42 posi, PS, 4-wheel PDB, Old Air AC & GM Tilt column.