Spark Plug Wire Question

Dec 21, 2003 9 Replies

I have a 1972 350 4 barrel with HEI, in a 1967 chevy C10 pickup which isn't driven much. Recently changed Spark Plugs and it runs fine except under load and then it cuts out but if you let off gas it runs smooth again. Checked under hood at night and there are no obvious arching between wires or to ground. Are the wires still the most like culprit. They haven't been changed in 20 years, Yea I know, but they never caused any problems. TIA


Could also be the carb out of adjustment, spilling too much fuel into the intake.

After 20 years, change the wires anyway. Your truck will thank you :) Vuarra

Quid quid latine dictum sit altum videtur. (That which is said in Latin sounds profound.)

They can look fine on the outside and still be no good. The core becomes brittle and twisitng and wiggling them to remove and replace them might have separated the core in one or more of them. You can pull them off and check with an ohm meter but after 20 years I wouldn't even bother I'd just replace them with a good quality set. Even if it isn't all your problems the new wires won't hurt.

"BillW" wrote in news:mFhFb.17816$P% snipped-for-privacy@newssvr28.news.prodigy.com:

I replace it regularly as it seems to clog frequently, I'm going to clean the gas tank next summer. I just wanted to make sure I hadn't overlooked the obvious. Thanks for responding.

One thing to remember when putting an HEI in an older vehicle is to be sure the HEI is being fed full battery voltage. Do not use the same wire that powered the coil on the 67. Run a new 10ga. wire from a switched source, usually the fuse block.

"pm" wrote in news:bs5unb$2sde$ snipped-for-privacy@news3.infoave.net:

The truck has been running fine for the 20 years i have had it so I don't think any gremlins have messed with the HEI.

tango wrote in news:Xns9459EE90CE5B1999586@216.168.3.44:

I phrased the above response badly so don't be offended PM. I should have said the HEI has been on the truck for the 20 years I have owned it. All responses are appreciated.

OK, I didn't know. Assuming the coil, cap, rotor have been eliminated, it could be the wires on the pickup coil have almost broken off or the coil is week.

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