Ignition Module recommendation

[Coach]

Can anyone recommend a quality ignition module for my GM HEI Distributor - I've gone through (2) Standard Motor Products LX301's in the last couple months.

[LockDoc]

Originally Posted by Coach

Can anyone recommend a quality ignition module for my GM HEI Distributor - I've gone through (2) Standard Motor Products LX301's in the last couple months.

Might try your local GM dealer. Probably pay a little premium.

I started using computer thermal heat sink paste (Arctic Silver) on the modules instead of the stuff that comes with the new ones.

https://www.amazon.com/Arctic-Silver.../dp/B07NV27PDX

I think it works better. All you need is a real thin skim coat. You may be able to find it cheaper if you look around.

LockDoc

[BigBird05]

When it comes to electronics always try to buy OEM parts. If you are going thru modules check your voltage at the distributor when the truck is running. These modules don't like low voltage.

[truckster]

I agree with the silver thermal paste - it's way better.

Also check your voltage at the distributor.

[tdangle]

Something is taking them out. I ran a cheap HEI clone for years with no problem. Make sure you have full battery voltage at the distributor. running should be between 13.5 and 14.5 volts. Also when replacing the module, use the paste as this helps transfer heat from the module to the body of the distributor.

[Coach]

Thanks fellas. I have 13.8 volts when running. I am going to try the silver paste and an AC Delco D1906 module and see how that goes.

[toolboxchev]

Originally Posted by Coach

Can anyone recommend a quality ignition module for my GM HEI Distributor - I've gone through (2) Standard Motor Products LX301's in the last couple months.

Lets first start at the root of a common problem.

Do you have an upgraded internally regulated alternator or do you still have the stock external voltage regulator?

Excessive voltage demands with the external system lead to high voltage spikes which in turn fry the HEI modules. I go through one about every 1 to 2 years. The internally regulated alternators do not let the amp/voltage spike when demand is high. I believe from knowledge passed about on the board the internally regulated unit do not let charging increase past somewhere around 14.0 volts.

It follows classic electrical theory in battery charging lower voltages and longer charge times do not cook the standard lead acid battery.

[68 P.O.S.]

Check on your coil. HEI coils can overheat and layer short, which can take out modules pretty quickly.

[Bigdav160]

Originally Posted by 68 P.O.S.

Check on your coil. HEI coils can overheat and layer short, which can take out modules pretty quickly.

That's what I was going to say. The coil is the likely root cause here.

[toolboxchev]

Originally Posted by 68 P.O.S.

Check on your coil. HEI coils can overheat and layer short, which can take out modules pretty quickly.

Would venture to speculate that an over voltage situation would do this also. I have seen my own vehicle pump out over 19 volts at idle when the external voltage regulator goes bad.

[Coach]

The frustrating part is the module (LX301) and coil (DR31) were both replaced at the same time a couple months ago, just to be safe. I will probably replace both this time as well, as i am going to be putting the truck up for sale to help pay for my son's college and I don't want to sell the truck to someone with any issues.

[68 P.O.S.]

Originally Posted by toolboxchev

Would venture to speculate that an over voltage situation would do this also. I have seen my own vehicle pump out over 19 volts at idle when the external voltage regulator goes bad.

Yes, most definitely

[68 P.O.S.]

Another idea, check to see if you still have the stock resister power wire in place. It was meant for the points distributor and will not give the proper voltage. If so, it needs to be changed.

[TALLone71]

thanks locdoc, for the tip on the thermal paste, I have always used the grease they supply with the new module, but have wondered about a better thermal barrier, and this looks like the ticket!

[LockDoc]

Originally Posted by TALLone71

thanks locdoc, for the tip on the thermal paste, I have always used the grease they supply with the new module, but have wondered about a better thermal barrier, and this looks like the ticket!

No problem. Just remember a thin skim coat. Too much can be as bad as not enough....

LockDoc

[leftybass209]

To keep replacing modules is probably not coincidence at this point. Bad grounding can kill a module. Do you know if the bent metal ground strap is inside the cap under the coil?

Ground straps to motor okay?

It's possible you have higher resistance for the ground when driven at temp. Did you verify voltage on a hot motor, hot day?

I just think... if you're a capable mechanic, and you used thermal paste, then 1 new burn out is a fluke, 2 is suspect that it's not the module. The difference in thermal paste isn't so great that the stuff provided shouldn't give you years of use. Best of luck getting it sorted.