Lost another HEI module
 

This one lasted about 7 years. Pretty much a record for me. About three modules ago I bought the more expensive one from O'Reilly that had a lifetime warranty. This is the third one I've gotten on that warranty. Guy at the store was a little salty with me for the replacement, commenting that I bought the original 8+ years ago (first one only lasted a year). I just pointed out that that is exactly why I bought the one with the lifetime warranty.....

I had a Pertronix module in reserve I hadn't actually installed yet so I put it in today. Works great. I now have a Standard from O'Reilly and an NOS GM module from the 70's in reserve in the glovebox.

In the 26 years I've had the truck, and it has had an HEI in it for about 25 years, I've probably put in about 6 modules. The original, the used GM module that came with the junkyard HEI, lasted the longest.

Usually they give out as I'm driving along. The one today gave out when I went to start the truck after sitting parked for about 10 minutes. Truck wasn't even warmed up yet, all I had done is move it from one storage spot to another to pick up some stuff.

And yes, I use thermal paste under the modules every time, I no longer use the crappy silicone paste that usually comes with the modules, that stuff seems to make them fail even quicker.

Re: Lost another HEI module
 

Auto parts are hit-and-miss these days, but I rarely shop at O'Reillys anymore because of poor customer service. Are you using the silver thermal paste? I buy it from computer supply houses.

Re: Lost another HEI module
 

Yes, using computer processor thermal paste.

Re: Lost another HEI module
 

Some people can use words without grasping that they mean things ;-)

When my dad worked for a defense contractor somebody complained "I gave the guy an unlimited budget and he spent it in a week" :banghead:

Re: Lost another HEI module
 

Accel makes one
Wonder if they are any better.

Re: Lost another HEI module
 

I have a Mallory distributor but don't know who made the module. It's 26 years old with about 90k miles on it. Probably ought to buy a spare at this point.

Re: Lost another HEI module
 

"broad"?

Re: Lost another HEI module
 

Do you have anything on the "R" or "I" terminal on the starter solenoid?

The ignition coil Primary winding generates a high voltage spark WHEN the 12 volts is REMOVED from the coil. 300-400 volts of Back EMF on the primary winding.

The AC clutch coil will create Back EMF when the AC cycles OFF. That's why they usually have a diode on the clutch.

The starter solenoid has TWO large coils and can create back EMF.
On the inside of the solenoid "R" or "I" terminal, depending on how it's labeled or who is telling the story, there is a little hooked shaped arm. The arm touches the washer/disc when the solenoid is energised.
The washer isn't really held rigid and can flop around a little bit.

If that arm is bent in such a way that it makes contact with the washer, AFTER the solenoid RELEASES, it is possible the Back EMF can make its way from the "R" terminal up to the distributor and destroy a HEI module.

With a standard points ignition, a stray EMF spike from the solenoid would go completely unnoticed in the distributor.

Re: Lost another HEI module
 

Those capacitors were in the ignition system for a reason. Now that I think about that, OP, have you ever checked the capacitor in the bottom of the distributor body on your HEI distributor? Don't feel like I'm picking on you; I haven't ever checked mine, either. Just a thought that came to mind from reading through this thread.

Re: Lost another HEI module
 

I've never had a set of "points" fail

Re: Lost another HEI module
 

Good (point) :lol:

Re: Lost another HEI module
 

Back feeds are a good thought. I'm sure you know, and for others that may not, the factory +12v lead to the coil, yellow wire, is a stainless steel resister wire. It needs replacement with a copper wire or it will burn out the HEI module do to low voltage over time. Once replaced, the jumper to the solinode is moot and can be removed and may reduce back feed from the starter as described above.

Re: Lost another HEI module
 

I have. :D

Everything in this HEI has been updated. Most when I first got it out of the junkyard (cap, coil, vacuum advance) and the module and pickup were okay so I kept them. I also installed a vacuum advance limiter. Rebuilt and regreased and worked great for a long time. Then the first module popped. Luckily I figured out it was the problem and I've always carried a spare with me at all times since. After about the 3rd module the HEI harness fell apart and the wiring to the pickup coil was shot. So, a new pickup coil and harness were installed. Still popped modules from time to time.

When I first installed it I ran a dedicated 12v to the HEI. Later I installed a new engine harness designed for HEI use having a dedicated 12v instead of a resistor wire.

Everything works great, except for the occasional module failures. I now carry two spares with me at all times. The engine fires at the first touch of the key, so any time I have to crank more than 2 seconds (other than when it is cold and has been sitting for weeks or months) I know what the problem is. But usually the modules fail while driving, which is much less convenient. It once died in a busy left turn lane. Luckily a friendly road construction crew nearby was able to help push me into a nearby parking lot where I could fix it. Most often I have to fix it on the shoulder of a busy highway. Sometimes when it dies, I can let it rest for a bit and it will restart again, only to die again a short while later. Usually they fail when it is hot out, the other day though that was not the case. No real rhyme or reason, they just pop when they pop.

Re: Lost another HEI module
 

>>yellow wire, is a stainless steel resister wire. It needs replacement with a copper wire or it will burn out the HEI module do to low voltage over time. Once replaced, the jumper to the solenoid is moot and can be removed and may reduce back feed from the starter<<

>>yellow wire, is a stainless steel resister wire.<<

WRONG. The yellow wire is the by-pass around the resistance wire that the solenoid provides from the "R" terminal. The Resistor Wire is the Cloth covered W/Or/Ppl wire shown in the schematic. Check your schematic before posting incorrect information.

>>burn out the HEI module do to low voltage<<

WRONG. Low voltage WILL NOT burn out a HEI semiconductor module.
When is the last time you had a HEI burn out when you had a low battery or a failed charging system. You can start a engine with NO charging system and the HEI will continue to operate flawlessly until the battery voltage drops below about 8.5 volts. The HEI will fail to operate below that voltage, but it will never be damaged.
The HEI in my 292 has operated flawlessly for more than 30 years with the resistor wire still in place. Actually TWO HEI's. A coil-in-cap HEI and now a external-coil HEI.
I've driven cars 50 miles with a failed charging system and a charged battery of course and the HEI never failed.

>> the jumper to the solenoid is moot<<

The jumper to the solenoid SHOULD be REMOVED for the reason I described in my other post.

Semiconductors do not like overvoltage, they do not like supply voltage spikes and they do not like excessive heat.

Re: Lost another HEI module
 

There is a tee splice where the resistor wire from the ignition switch meets the yellow wire from the R terminal on the starter solenoid

The third wire from that tee that runs to the coil+ post(Primary) is also yellow

I checked my schematic before posting this information

Re: Lost another HEI module
 

Sorry I was not clear. From memory. And its not so good, the +12 wire to the coil is yellow. It runs from the coil to the starter solinode. In the harness is a splice on that yellow wire. The wire that runs from the firewall harness connector to the splice within the harness and is the resistor wire. I do not recall if it was yellow or a different color. That is the wire I am referring to. As for low voltage not damaging semiconductors. That may be a true statement in and of itself but it can exacerbate problems in the module if the path is not perfect to the coil and out the otherside. I understand a semiconductor is not a motor but spikes and over heating could happen and replacing that wire between the coil, solinode, and firewall connector can't hurt assuming you are using a coil that can handle the full time higher voltage.

Re: Lost another HEI module
 

...as long as we keep our misogyny up to date

Re: Lost another HEI module
 

I'd try a real AC Delco Gold #D1906. Cost is $41.79 at Rock Auto.

I have one as a spare for the MSD module in my truck that's still working fine after 20+ years! But it was probably made in MSD's El Paso, TX factory.:flag: That was before the conglomerate that bought Holley, MSD, and dozens of other companies and switched manufacturing to China.

Edit: Should have mentioned the coil is also MSD. Again, it's one that's 20+ years old.

Re: Lost another HEI module
 

Modern AC Delco versions are not any better than random aftermarket brands. The best I've heard are NOS ones from the 1970's are the best around but are really hard to find any more. I have one, but I'll only use it if the Pertronix one fails.

Re: Lost another HEI module
 

If HEI modules get that problematic, as stated above by others, I'll go back to points.

Re: Lost another HEI module
 

HEI module issues are usually caused by something else in the ignition system and usually the coil . My dad's Olds blew modules until I replaced the coil but the issue is usually in the coil or secondary system.

I've got the pre computer (4 pin module) HEI test procedures from Napa here in my photobucket but was told the other day unless you have an account you can't open it. https://photobucket.com/bucket/c5e80...8-34b5e1631d08

Here are the pages. to copy and save. The pages may not be in order because Photobucket seems to like to mix the order of things lately.

https://hosting.photobucket.com/c5e8...720&fit=bounds

https://hosting.photobucket.com/c5e8...720&fit=bounds

https://hosting.photobucket.com/c5e8...720&fit=bounds

https://hosting.photobucket.com/c5e8...720&fit=bounds

https://hosting.photobucket.com/c5e8...720&fit=bounds


https://hosting.photobucket.com/c5e8...720&fit=bounds

Re: Lost another HEI module
 

I recently had an alternator go bad (17vdc) and it caused the ignition module to induce spikes (data log graphing showed them). So...check your alternator output. I replaced the blown alt tri-ode AND the ign module but all is well now. I keep a sharper eye on my alt output these days.

Re: Lost another HEI module
 

Maybe it's a case of coil resistance. I do know that Pertronix, for example, requires specific coil resistance for their various modules.

You hear a lot of bad things about Pertronix modules failing, but maybe it's because people don't buy the coil with the module.

I have a friend with two of their module/coil combos in 302 Ford engines. But it's been less than a year, so I guess we'll see how well they hold up. Also, I used to work part-time for a guy at a hot rod/muscle car shop who swore by Pertronix, and he couldn't afford to use parts that failed.

Re: Lost another HEI module
 

This is the spare I bought last year. Maybe this one is NOS, but I'd still be inclined to disagree with your blanket statement.

Re: Lost another HEI module
 

I replaced the alternator last Fall along with the voltage regulator as I needed a little more power for some stereo equipment I had installed. Both are top quality Tuff Stuff parts. Popped modules with the old system and now again with the new.