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question about hei & tuning
https://slantsix.org/forum/viewtopic.php?t=59981		 Page 1 of 1
Author:  bashmaki [ Wed Aug 03, 2016 8:06 pm ]
Post subject:  question about hei & tuning
I burned out another module. This makes 4 so far in about 5000 miles. Each time I found something amiss. Either I didn't follow the conversion procedure to a T or I was having over charging issues & burned out two of them.

Now the only thing I can find wrong is the distributor cap doesn't look to good. It was just a Napa shelf replacement. Could this ACTUALLY burn out one of these modules or should I keep looking.
I've ordered the super duper tune up parts suggested in hopes that I can actually begin to trust this old pickup again.
I just can't remember any vehicle I've ever owned that has left me stranded this many times.

It is no grounding issue as this thing is grounded real good. I have continuity everywhere.
Author:  Pierre [ Wed Aug 03, 2016 9:54 pm ]
Post subject: 
Keep looking, a cap won't burn a module.

Assuming your charging / wiring issues are worked out, your down to either a mismatched coil or mounting issues. What's the module mounted to and how? Heat can become an issue if it's not sinked well
Author:  bashmaki [ Thu Aug 04, 2016 4:55 am ]
Post subject: 
My coil set up is from a 1997 Jimmy. I have the complete mounting bracket & heat sink for the coil & module right down to the factory connector to the coil. This is mounted on the inner fender well, right side. It is solid with a double ground. It was grounded plenty good through the fender well but I put a strap on anyway for good measure right away.

I put a new OEM regulator I bought from oldcarparts.com. Says Mopar right on it. After installation 6 weeks ago or so it was testing @ around 13.4 or so. I'll have to check it again once I get a module back on that works.
Author:  DadTruck [ Fri Aug 05, 2016 6:51 pm ]
Post subject: 
Are you sure the module is fully seated to the aluminum heat sink? And what compound is being used between the module and the aluminum heat sink.

Also have you verified that the module that you took out actually failed, put a 'bad' module back in and verify the no start, it is possible that you have an intermittent wiring issue and in the process of swapping modules you temporary resolve the issue,
Author:  Charrlie_S [ Sat Aug 06, 2016 4:46 am ]
Post subject: 
Are you using the 4 pin module on the jimmy heat sink? If yes, then you need to either remove the locating pin on the back of the module, or drill holes in the heat sink, for the pin to go into. If you don't do this, the module will not sit flat on the heat sink, and over heat.
Author:  bashmaki [ Sat Aug 06, 2016 6:21 am ]
Post subject: 
Dadtruck,
The grease I use is 100% silicone grease. It is labeled VeraChem brand. It has Polydimethylsiloxane (according to the label) I hope that's the right stuff !

I have tested the module with a meter and it is no good. As in burned out. My education in electronics and 40 yrs. In the field as a tech. has verified this fact. I'm NOT going to try to tell you that I haven't made a few mistakes along the way. My experience tells me that if I've been working on something and it fails again soon after the last repair; it is probably my fault. That very well could be the case this time.
I am going to go through all my connections and replace anything remotely suspect.

Charlie, I always cut the nub so it is lower than the back plate on the module. Thanks for the suggestion.

Pierre suggested maybe the coil & these modules are incompatible. He could be onto something there.
I have two NOS DelcoRemi modules coming in the mail. I'll let you know how it goes.

Thanks for the input guys.
Author:  Charrlie_S [ Sat Aug 06, 2016 7:41 am ]
Post subject: 
Quote:
Dadtruck,
The grease I use is 100% silicone grease. It is labeled VeraChem brand. It has Polydimethylsiloxane (according to the label) I hope that's the right stuff !
I'm thinking this is not correct. Silicon grease, is insulating. You need a thermal conducting grease.
Check this link. http://www.fullsizebronco.com/forum/23- ... rease.html
Author:  bashmaki [ Sat Aug 06, 2016 8:38 am ]
Post subject: 
OK Charlie, An interesting explanation of the different greases and their respective properties.
I have to run to town today; I'll copy down those part numbers and see if I can get some THERMAL grease this time.
Once again I've proven to be my own worst enemy :oops:

Thanks for the link, tip & all!
Author:  DadTruck [ Sat Aug 06, 2016 9:55 am ]
Post subject: 
yes, you want thermal conducting grease,,
Author:  bashmaki [ Sat Aug 06, 2016 8:17 pm ]
Post subject: 
OK Charlie, An interesting explanation of the different greases and their respective properties.
I have to run to town today; I'll copy down those part numbers and see if I can get some THERMAL grease this time.
Once again I've proven to be my own worst enemy :oops:

Thanks for the link, tip & all!
Author:  bashmaki [ Mon Aug 08, 2016 8:15 pm ]
Post subject: 
OK, now I don't feel so stupid!

Today in the mail I recieved, in the original packaging, an NOS, Prestolite, DelcoRemi module. In the box is an old yellowed instruction sheet that, in part, says this. I quote!

"2. Apply a liberal coat of the silicone compound, contained in the packet, to the metal mounting surface of the new module."

This is no argument for using the wrong thing, BUT, it does make it dang tough to do the right thing if your bombarded by misinformation 90% of the places you look! So beware of what you are buying, the instructions therein AND the bozo' s at the auto parts stores.

BTW, there was a nice little packet of silicone grease with the word "Dimethylpolysiloxane" right on the package; in with the module.

Thought this was extremely interesting & worth sharing.

Oh, and I just picked up 2 Blue Streak CH-403x distributor caps for $20.00 woohoo!!!! These baby's are hefty! :lol:
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