MSD 6A Box Driving a K-66 TI Distributor??

[Tom C.]

Anyone who has been following this forum lately knows that I have submitted a considerable number of posts concerning my freshly rebuilt (and now malfunctioning) K-66 TI system. The car runs great until it warms up and then quits. No spark. It will start and run after it has cooled off a bit. It also runs great (forever, no problems) with my conventional single point tach drive distributorand is not affected by heat with this system.

In order to isolate the problem to the TI distributor or the amp I need to try the distributor with some other form of amplification. I have been told by an old racer that they often used the K-66 distributor with a MSD 6 box and it works well, but he can't exacly remember how it attaches to the 2 wire connector coming off of the TI distributor. Has anyone tried this trick? Or any other alternate means of using the TI distributor? If so, how did you wire it up?

[Dick W.]

Re: MSD 6A Box Driving a K-66 TI Distributor??

MSD works fine with TI distributor. GM NASCAR cars ran this set up for several years. Go to the MSD web site and you should be able to get a schemetic.

[A L.]

Re: MSD 6A Box Driving a K-66 TI Distributor??

Tom, I don't know anything about the MSD application, but do know about solid state electronic trouble shooting. I have seen electronic devices fail at some point during warm-up due to thermal break down of transistors, IC chips, resistors, capacitors, coils, fractured etchings, poor solders etc. The most common way to deal with thermal issues is a can of freeze-it(my generic name). This stuff can be purchased at most electronic supply houses and probably Radio Shack. It comes in an spray can with a tube so that it can be aimed at a specific area. It works best when you can get to individual components and freeze them one at a time. In this case, I would start with the amplifier. When ignition is lost, immediately cool it down, at least enough so that it is cold to the touch, then see if the car will start. If you can localize the problem to the dist. or amp.,then you can start on individual components.
AG

[Duke W.]

Re: MSD 6A Box Driving a K-66 TI Distributor??

You can also use a four-pin HEI module, which only costs about 25 bucks, and maybe you can find someone locally who has a spare. Contact Clem for a schematic on how to wire it in. Two of the HEI pins are for the two pickup coil leads. One is for the coil neg. terminal and the fourth is 12V power.

It's pretty simple, but you will have to cobble up some test leads. The HEI module also needs to be grounded and be mounted on a heat sink. You can probably temporarily mount it to the radiator support using one small machine screw and nut on an available hole.

As a final fix, if it works, I believe it can be mounted inside the TI amp housing. This is an excellent solution. Since the HEI module was designed to take the heat and vibration of internal distributor mounting, it will last virtually forever in the cool low vibration mounting of the TI amp. The biggest problem will be potential moisture corrosion inside the amp housing and connector. That's probably not going to be an issue if you don't usually drive the car in the rain, but the amp interior and connector should be checked every few years. Use a thin film of silicone grease on the amp cover gasket and connector boot.

Duke

[Tom C.]

Re: 4 Pin HEI Module

Sounds like a great isolation/troubleshooting tool. Where might one purchase one of these modules?

[Clem Z.]

Re: 4 Pin HEI Module

it requires a completly different wiring setup than TI system. use the MSD box and you will know if the distributor pickup coil is the problem

[Phil P.]

Re: 4 Pin HEI Module

auto parts store or chevy---the module from gm is marked with a W G at one end which i'm pretty sure is the WHITE and GREEN for the pickup coil in the dist---the other end ins marked with a B and C, B = 12V and the C will go to the coil---if i'm wrong someone out there will correct me---good luck,phil

[Rex T.]

Re: 4 Pin HEI Module

Does anyone know if an adequate replacement gasket is available for sealing between the module housing and the back plate? Thanks Rex

[Alan Drake]

Re: MSD

Tom,
Ran a MSD model 6200 since it hit the market until 3 years ago. Mounted on thick (3/8) section of aluminum and routed to rear compartment behind driver's seat. Now it works just fine, so if you can borrow one try it.

[Tom C.]

Re: Braided Stainless Plug Wires-Solid Core??

There have been a couple of comments that the reproduction braided stainless grounded plug wires are suspect. MSD says DO NOT use solid core wires. Does anyone know if the repo braided stainless (grounded) wires are solid core?

[Howard Nardick]

MSD/TI wiring

I ran that setup for years on my vintage racer...your TI has a white wire and a white wire w/green stripe....white goes to the violet/purple wire while the green striped TI wire goes to the green MSD wire. Small red to the ignition key, orange to the + on the coil and the small black to the - on the coil, white is NOT used...the large red and black are power/ground leads.....I also always used an MSD coil. ..HN

[Clem Z.]

Re: Braided Stainless Plug Wires-Solid Core??

no they are resistance string. i think the problem is voltage leak thru to the braid. i ran MSD ignition with solid core stainless plug wire with no problems but i may have been lucky. the say EMF will mess up the electronics in the MSD box. some solid core plug wires are shielded internally to prevent and problems with the MSD

[Duke W.]

Re: 4 Pin HEI Module

You can buy a four-pin HEI module at any parts store in a variety of brands - Delco, Echlin, BWD, Standard, and probably a number of "off-brands". You can get a NAPA number on their Web site. Most of the brand name modules are probably manufactured by Standard. They were used on tens of millions of GM cars/trucks from 1975 to into the eighties, and the same module is used regardless of number of cylinders. The four-cylinder Vega module is the same as a Corvette L-82. They're also ubiquitous in salvage yards on all GM vehicles of that era.

Since the kid behind the counter will probably have no idea what an "four-pin HEI module" is and will likely want the year/make/model, just say 1975 Chevrolet - any model - any engine.

All the four-pin HEI modules are functionally the same. The later seven pin module HEI systems have spark advance control integrated into the system. The first generation "four-pin" HEIs have conventional centrifugal and vacuum advance systems like the old single point and TI systems.

Duke

[Barry Chappell]

Re: 4 Pin HEI Module

The HEI module is a really easy setup. Several years ago I put a box together using the HEI module. (From an old HEI dist.) I carry it as a spare "TI" module, as I'm still using the original TI unit, and I'm sure it will fail someday.

I've never used it for more than testing to see that it will work.
I used an old external aluminum voltage regulator case. (Looks like a TI unit)
You could use any heatsink from an electronics parts store.

Connect a few wires using spade connectors and you have a "plug-in" replacement for your TI module.
If just for testing, mount it in a plastic container attached somewhere convenient.
Barry

[Tom C.]

Re: Gm Troubleshooting Bulletin K-66 Ti Ignition

Myron, Thank you very much for all the work you put into sending this stuff to me. I really appreciate it. I'm beginning to wonder whether or not a system so full of problems of worth trying to run on my car anyway.

It will make a nice museum piece or Barrett Jackson auction conversation item someday if I finally get it operational. Puzzles like the K-66 should become quite valuable if not only for their inherent "hair pulling" capabilities. No wonder the system was abandoned by GM early in the game.

I am amazed that Dave Fiedler can make a living fixing this stuff and tell people (with a straight face) that it is good and reliable engineering.

Thanks again for all the scans.

Tom Cheairs
NCRS 29773