HEI Ignition modules only last 1000 miles
Thread Starter
Racer
Joined: Dec 2000
Posts: 385
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From: Blue Ridge GA
HEI Ignition modules only last 1000 miles
I've had a problem in my 1986 with ignition modules constantly burning out. I've tried cheapos, NAPAs, GMs and Accels and all have burned out. I do have a MSD 6A but that is the only modification. HELP!!!!
Ben :mad :mad :mad
Ben :mad :mad :mad
Instructor
Joined: Sep 2002
Posts: 116
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From: Boise ID
Re: HEI Ignition modules only last 1000 miles (Stealthvette)
Just a couple of thoughts. Are you putting enough heatsink grease on the bottom of the module and being careful not to over torque the hold down screws. Heat and stress are two of the major factors that can shorten a chip's life. Hope this helps.
Team Owner
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From: Athens AL
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Re: HEI Ignition modules only last 1000 miles (Stealthvette)
Have you disconnected the MSD and waited to see if one failed?
Team Owner
Joined: Mar 2001
Posts: 54,124
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From: Cincinnati, Oh USA
Re: HEI Ignition modules only last 1000 miles (Stealthvette)
It isn't the ignition modules you are burning out, its the spark coil. The factory coil is designed for 12v pulses from the ignition module and your MSD ignition puts 540 volt pulses on the coil and burns it out in 1000 miles. Buy the coil from MSD intended to be used with their ignition package.
While you are at it, buy the MSD pin for the center of the distributor cap as the factory carbon button burns out from the higher energy output from your MSD package.
[Modified by jfb, 11:09 PM 2/25/2003]
While you are at it, buy the MSD pin for the center of the distributor cap as the factory carbon button burns out from the higher energy output from your MSD package.
[Modified by jfb, 11:09 PM 2/25/2003]
Thread Starter
Racer
Joined: Dec 2000
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From: Blue Ridge GA
Re: HEI Ignition modules only last 1000 miles (ethan1321)
Yeah, I've always been diligent about making sure there was plenty of the grease on the bottom of the module. Don't know about tightening it down too much. How much is too much?
Thread Starter
Racer
Joined: Dec 2000
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From: Blue Ridge GA
Re: HEI Ignition modules only last 1000 miles (vader86)
Actually, I haven't disconnected the MSD to see if that works better. However, I DID have this problem with ignition modules BEFORE the MSD install.
Team Owner
Joined: Mar 2000
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From: Boston, MA
The MSD ignitions don't even use the control module once they are installed. The only thing the module is used for at that point is a crank signal so that the ignition knows when to fire.
As said get the MSD coil and low resistance HEI brush.
As said get the MSD coil and low resistance HEI brush.
Thread Starter
Racer
Joined: Dec 2000
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From: Blue Ridge GA
Re: HEI Ignition modules only last 1000 miles (jfb)
My spark coil? No, I've got the MSD "Blaster" coil setup, not the stock coil. Is that what you mean? Is that coil messing up my modules? Because when I replace the modules everything works again, for awhile. I thought the "button" on the distributor cap came with the cap. Do I need to get the MSD cap?
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Thread Starter
Racer
Joined: Dec 2000
Posts: 385
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From: Blue Ridge GA
Re: (scorp508)
I wish I could eliminate the control module from my system, it is such a PIA having these things going out on me all the time. It seems like MSD would have told me all the other things I need to change when I installed their system. I autocross this car and these durn things fail at an incredible rate. Of course I always carry a spare but that is a pain, too.
:banghead: :banghead: :banghead: :banghead:
:banghead: :banghead: :banghead: :banghead:
Team Owner
Joined: Mar 2000
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From: Boston, MA
I thought the "button" on the distributor cap came with the cap. Do I need to get the MSD cap?
Fire this part number into http://www.summitracing.com
MSD-8412
Thread Starter
Racer
Joined: Dec 2000
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From: Blue Ridge GA
Re: (scorp508)
Let's see if I understand the situation. It seems you are saying that the MSD puts so much more voltage/amperage through the distributor cap that the button can't handle the extra load creating extra heat inside the distributor which, in turn, cooks the internals of the ignition module. Is that correct?
Ben :confused:
Ben :confused:
Team Owner
Joined: Mar 2001
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From: Cincinnati, Oh USA
Re: (Stealthvette)
The MSD button will not harm your ign module, but an incorrect spark coil might. The GM module was designed to work with the GM spark coil. An MSD button is required with the MSD capacitor discharge ignition system because the current pulses in the spark are so much higher that they heat up the GM button and it melts the distributor cap.
Thread Starter
Racer
Joined: Dec 2000
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From: Blue Ridge GA
Re: (jfb)
Yeah, I talked to MSD, today. They said that a stock button wouldn't have any affect on the ignition module because all the heat is above the rotor and separated from the ignition module. I think I must have put an MSD button in when I installed the system as they say trying to run a stock button will usually end up with a melted rotor and/or cap. I've ordered another one, just in case I've been lucky.
A friend of mine suggested that I might have a ground problem. I suggested this idea to MSD and they said that a bad ground could, indeed, cause ignition modules to fail. They suggested wiring a ground from the distributor to a good ground source.
I have moved my battery to the compartment behind the passenger seat and the ground lead goes to the big bolt that attaches the C-beam to the rear-end. I would think that would give a solid ground. I know that my starter has no problems at all.
A friend of mine suggested that I might have a ground problem. I suggested this idea to MSD and they said that a bad ground could, indeed, cause ignition modules to fail. They suggested wiring a ground from the distributor to a good ground source.
I have moved my battery to the compartment behind the passenger seat and the ground lead goes to the big bolt that attaches the C-beam to the rear-end. I would think that would give a solid ground. I know that my starter has no problems at all.
Thread Starter
Racer
Joined: Dec 2000
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From: Blue Ridge GA
Re: (Stealthvette)
I've got a new "Low Resistance Bushing" for the cap and I ordered MSD-8861 which is a small wiring harness that converts the ignition module to a trigger, only, for the computer. This should lower the temperature build up in the IM since no firing voltage will be going through it. I'll keep everyone posted.
Ben :chevy
Ben :chevy
Burning Brakes
Joined: Oct 2002
Posts: 1,193
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From: Meadville PA
Re: (Stealthvette)
it's the pickup coil....trust me....if you keep blowing out perfectly good modules for no reason...9 times out of 10 you have a pickup coil that is really the cause ..this is very common to hei spark systems...the fact you have an msd is really irrelevant.. when you pull your dist check the dist shaft bushings they are known to wear on high millage dist and cauce the pick up to actually short out... there should be very little play in the dist shaft...also buy a good pickup coil like from gm. check bushings if good replace pickup coil and module...my bet is problem will be gone and you'll be happy :cheers:
:steering:
:steering:
Thread Starter
Racer
Joined: Dec 2000
Posts: 385
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From: Blue Ridge GA
Re: (1989redvette)
What do you mean by "pickup coil?" I have installed the MSD Blaster coil when I put in the MSD ignition. Now, refer to my previous post about putting in MSD's (#8861) cable that wires the MSD directly into the distributor trigger and bypasses the spark current around the module. Shouldn't this solve the problem?
It sounds like you are saying that I may have a problem with distributor bushings being worn out, too. Is this something I can rebuild or do I need to have a professional handle that job?
:confused: :confused: :confused:
It sounds like you are saying that I may have a problem with distributor bushings being worn out, too. Is this something I can rebuild or do I need to have a professional handle that job?
:confused: :confused: :confused:
Burning Brakes
Joined: Feb 2000
Posts: 927
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From: Saginaw TX
Re: (scorp508)
That would be the round piece surrounding the shaft next to the module. Also has two wires running to the module. The coil actually sits in a housing that has the ring with the points facing inward that he star wheel on the shaft lines up with. Gesh that's a tough one to describe. Scorp's right, gotta pull the gear off and the shaft out to change.