ok, now i'm sick and tired. In about 8 months I've gone thru 3 coils, the latest victim an MSD /forums/images/graemlins/angryfire.gif. What could be burning them up? I know points type ignitions should only be getting 6 volts (running), but what should an HEI get while running? Thanks, Tom.
CK5
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volts to hei?
- Thread starter dubl_t
- Start date
MOABDADC22
1/2 ton status
You have to have a full 12v. Best thing to do is run a new lead from the fuse box all the way to the "bat" terminal on your hei. Do not attempt to splice into the old 6v resistor wire.
HEI's are power hogs. They not only want full battery voltage, they will pull a fair amount of amps too.
I would suggest that you get a 'universal' Bosch type relay and mount it somewhere convenient. Run at least a 10 gauge wire from the battery to one of the high current terminals, and another 10 gauge from the other high current terminal to the HEI. Use your existing IGN power feed (minus any resistor or resistance wire) to control the relay.
What sort of sparkplug gap are you using ?
I would suggest that you get a 'universal' Bosch type relay and mount it somewhere convenient. Run at least a 10 gauge wire from the battery to one of the high current terminals, and another 10 gauge from the other high current terminal to the HEI. Use your existing IGN power feed (minus any resistor or resistance wire) to control the relay.
What sort of sparkplug gap are you using ?
gap= .060 (platinums), like I said, the dist. has been decked out w/MSD stuff. Sometimes when I try to start it, she cranks over w/no spark. I know there's power to the "batt" terminial though. While idling cold, sometimes she shuts down suddenly and then fires agin. sounds like maybe a short to the "batt" terminal?
Moabdad, did u used to belong to Rough Country 4wheelers?
Moabdad, did u used to belong to Rough Country 4wheelers?
TopOff
1/2 ton status
You keep losing Coils?
Could be a bad or missing groud strap on the coil. Do you have that funny looking ground going from the coil to one of the screws in the cap?
What HEI module are you running? How is it wired? - Stock connectors? Or is it reveresed?
MSD Troubleshooting link
http://www.msdignition.com/1troub1.htm#anchor336780
Magnetic Pickup
in the Distributor
The magnetic pickup in MSD Distributors can also be checked with an Ohm meter to make sure it is within operating specifications. Once again, connect the Ohm meter's leads to the two terminals of the pickup. The resistance should be within 400 - 1,300 ohms. If the resistance is out of this specification, inspect the condition of the wires leading to the pickup for abrasion, shorting or opens. If the wiring is okay, the pickup is at fault.
NOTE: The Ignition will check good if the pickup is at fault. Follow the Checking for Spark procedure.
Good luck.
Could be a bad or missing groud strap on the coil. Do you have that funny looking ground going from the coil to one of the screws in the cap?
What HEI module are you running? How is it wired? - Stock connectors? Or is it reveresed?
MSD Troubleshooting link
http://www.msdignition.com/1troub1.htm#anchor336780
Magnetic Pickup
in the Distributor
The magnetic pickup in MSD Distributors can also be checked with an Ohm meter to make sure it is within operating specifications. Once again, connect the Ohm meter's leads to the two terminals of the pickup. The resistance should be within 400 - 1,300 ohms. If the resistance is out of this specification, inspect the condition of the wires leading to the pickup for abrasion, shorting or opens. If the wiring is okay, the pickup is at fault.
NOTE: The Ignition will check good if the pickup is at fault. Follow the Checking for Spark procedure.
Good luck.
Thanks Topoff, The module is the MSD, and I'm using 2 ground straps on the coil! I didn't check the pickup module because it's a rebuilt dist, but I will tommorrww.
U know, another thing I thought of is maybe the detonation sensor is causing shorts?
The reason I "believe" the coils have gone bad is because there is infinite ohms between the "batt" terminal and where the carbon button would touch. Does this help?
U know, another thing I thought of is maybe the detonation sensor is causing shorts?
The reason I "believe" the coils have gone bad is because there is infinite ohms between the "batt" terminal and where the carbon button would touch. Does this help?
TopOff
1/2 ton status
I would say it's a bad module... but dang, I if the module is bad, then I would think the module would blow well before the coil(s).
What module are you running? I think MSD, will say it's the module or you need a line filter... (line filters supposed to protect the module from spikes in the electrical system.).
what kind of voltage are you getting at idle and 2000 RPMS?
(when it does run).
Maybe your voltage regulator is not working on your alternator and it is spiking over 17 volts to teh coil???
Seems like a long-shot though.
Good luck.
What module are you running? I think MSD, will say it's the module or you need a line filter... (line filters supposed to protect the module from spikes in the electrical system.).
what kind of voltage are you getting at idle and 2000 RPMS?
(when it does run).
Maybe your voltage regulator is not working on your alternator and it is spiking over 17 volts to teh coil???
Seems like a long-shot though.
Good luck.
