Ignition Coil Overheating? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

crm318 · 11-20-2010, 12:25 AM

I use my truck to do deliveries at my place of work and I drive it a good bit in a day (lots of starts also). Every once in a while, the truck will not start and just turn over. When this happened tonight, I had my timing light with me. I hooked it up and no flash. I poured a cup of water over the coil (HEI) and then sprayed a little carb cleaner to dry it off. It started right up. It happened again later on and this time, it wouldnt start. I had to let it sit for an hour. What could be causing this? How can I keep this thing cool? The coil is only a month old and the last coil did the same thing.

tim21391 · 11-20-2010, 12:46 AM

my guess maybe too much power going to it?

raycow · 11-20-2010, 05:59 AM

Is this a factory HEI with the coil in the cap?

Ray

cdowns · 11-20-2010, 06:28 AM

if your not getting a full 12volts or you have a bad ground both can lead to overheating

crm318 · 11-20-2010, 04:51 PM

What ground should I look for/clean? It is a factory style HEI.

hayhauler71 · 11-20-2010, 06:21 PM

some times there is a ground that is attached to one of the coil screws others have a ground strap under the coil that the coil sits on and is retained when the coil screws are tightened.

OhOneWS6 · 11-20-2010, 09:21 PM

Quote:

Originally Posted by hayhauler71

some times there is a ground that is attached to one of the coil screws others have a ground strap under the coil that the coil sits on and is retained when the coil screws are tightened.

They all have a ground strap. Other wise it won't run. Even thought the distributor is grounded through the body of the distributor, the cap is plastic and insulates the coil from ground. If the ground strap is not there the circuit is not complete. it's something to check.

CRM, Did you run a new wire for the HEI or did you use the existing wire from the old points setup? If you used the old wire there is resistance built into it. You need to run a new wire for the HEI. Where are you getting the coils from?

crm318 · 11-21-2010, 04:00 AM

OhoneWS6 Thank you for the visual. Yes, that is all in good order. When I got the truck, it had the original points distributor and ceramic insulator. i replaced it with a 12 gauge wire. Ill check the connections on it.

crm318 · 11-21-2010, 01:54 PM

I got my coil from Oreillys.

OhOneWS6 · 11-21-2010, 04:20 PM

Quote:

Originally Posted by crm318

I got my coil from Oreillys.

Oreillys usually has decent quality parts. I've had issues with a lot of Auto Zone stuff. Usually things like starters and alternators. I'd also check to make sure the alternator is not putting out too much voltage. Where did the distributor come from?

crm318 · 11-22-2010, 02:44 PM

The distributor is an aftermarket one that I bought brand new 7 years ago. The altenator is about 1/12 years old.

11-20-2010, 12:25 AM	#1
crm318 Alright Alright Alright Join Date: Mar 2004 Location: Midland, Texas Posts: 1,672	Ignition Coil Overheating? I use my truck to do deliveries at my place of work and I drive it a good bit in a day (lots of starts also). Every once in a while, the truck will not start and just turn over. When this happened tonight, I had my timing light with me. I hooked it up and no flash. I poured a cup of water over the coil (HEI) and then sprayed a little carb cleaner to dry it off. It started right up. It happened again later on and this time, it wouldnt start. I had to let it sit for an hour. What could be causing this? How can I keep this thing cool? The coil is only a month old and the last coil did the same thing. __________________ 1972 Cheyenne Chevrolet red and white 357ci, Vortec heads, GM Performance high rise intake, Comp 268H .454/.454 218/218 110 LSA Quadrajet carb, Flowtech headers, 2.25 40 series HEI, Curve kit, TH 350, 3.07 gears 275/60/15s on 15x8 rallies

11-20-2010, 12:46 AM	#2
tim21391 Registered User Join Date: Jul 2007 Location: Salina, Kansas Posts: 1,998	Re: Ignition Coil Overheating? my guess maybe too much power going to it? __________________ 1972 C-10...402/400..flowmaster 40 series 1967 Mustang 347 stroker/C-4 1966 Mustang 289/3-speed 2013 Mustang V6/6speed w/300 ponies I may be 23, but i sure do knows 67-72s are sexy! Its not MPG its smiles per gallon! build started 11/25/08 build thread: http://67-72chevytrucks.com/vboard/s....php?p=2993796

11-20-2010, 05:59 AM	#3
raycow Registered User Join Date: Mar 2003 Location: San Francisco, CA USA Posts: 2,454	Re: Ignition Coil Overheating? Is this a factory HEI with the coil in the cap? Ray __________________ Live more responsibly. Eat lower on the food chain. Eat vegetarians.

11-20-2010, 06:28 AM	#4
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Ignition Coil Overheating? if your not getting a full 12volts or you have a bad ground both can lead to overheating __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

11-20-2010, 04:51 PM	#5
crm318 Alright Alright Alright Join Date: Mar 2004 Location: Midland, Texas Posts: 1,672	Re: Ignition Coil Overheating? What ground should I look for/clean? It is a factory style HEI. __________________ 1972 Cheyenne Chevrolet red and white 357ci, Vortec heads, GM Performance high rise intake, Comp 268H .454/.454 218/218 110 LSA Quadrajet carb, Flowtech headers, 2.25 40 series HEI, Curve kit, TH 350, 3.07 gears 275/60/15s on 15x8 rallies

11-20-2010, 06:21 PM	#6
hayhauler71 Registered User Join Date: Aug 2009 Location: St. Paul MN. Posts: 1,996	Re: Ignition Coil Overheating? some times there is a ground that is attached to one of the coil screws others have a ground strap under the coil that the coil sits on and is retained when the coil screws are tightened. __________________ Fuzzy

11-21-2010, 04:00 AM	#8
crm318 Alright Alright Alright Join Date: Mar 2004 Location: Midland, Texas Posts: 1,672	Re: Ignition Coil Overheating? OhoneWS6 Thank you for the visual. Yes, that is all in good order. When I got the truck, it had the original points distributor and ceramic insulator. i replaced it with a 12 gauge wire. Ill check the connections on it. __________________ 1972 Cheyenne Chevrolet red and white 357ci, Vortec heads, GM Performance high rise intake, Comp 268H .454/.454 218/218 110 LSA Quadrajet carb, Flowtech headers, 2.25 40 series HEI, Curve kit, TH 350, 3.07 gears 275/60/15s on 15x8 rallies

11-21-2010, 01:54 PM	#9
crm318 Alright Alright Alright Join Date: Mar 2004 Location: Midland, Texas Posts: 1,672	Re: Ignition Coil Overheating? I got my coil from Oreillys. __________________ 1972 Cheyenne Chevrolet red and white 357ci, Vortec heads, GM Performance high rise intake, Comp 268H .454/.454 218/218 110 LSA Quadrajet carb, Flowtech headers, 2.25 40 series HEI, Curve kit, TH 350, 3.07 gears 275/60/15s on 15x8 rallies

11-22-2010, 02:44 PM	#11
crm318 Alright Alright Alright Join Date: Mar 2004 Location: Midland, Texas Posts: 1,672	Re: Ignition Coil Overheating? The distributor is an aftermarket one that I bought brand new 7 years ago. The altenator is about 1/12 years old. __________________ 1972 Cheyenne Chevrolet red and white 357ci, Vortec heads, GM Performance high rise intake, Comp 268H .454/.454 218/218 110 LSA Quadrajet carb, Flowtech headers, 2.25 40 series HEI, Curve kit, TH 350, 3.07 gears 275/60/15s on 15x8 rallies



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