TI Problem

[Barry N.]

I have a 1966 427/425 (vin #105630). The car came with a 207 coil and old style amplifier ( the one with the individual components soldered to the circuit board. The three wires are (1) Gray, (2) Brown and (3) Black. When I have the old amp board and 207 coil installed the car runs fine. I upgraded the amp module with one purchased from Paragon part # 1380 64-71. The original box it came in was from Lectric Limited labeled (VTR6571AM) Transistor Ignition Module. With this module installed in the original TI housing the car is very hard starting. It runs OK(?) but when you step on it, it totally breaks up as if the timing was off. I went back to the old module and the car runs fine. I purchased a 210 coil which I believe is the correct coil for an early 1966. When I have the new 210 coil and the old amp module the car is hard starting, it runs rough and when you step on it, it breaks up. I then tried the new 210 coil with the new amp module from Paragon and again its hard starting and the car runs worst of all the coil amp combinations
If anyone can enlighten me as to what is going on and how to fix it I would greatly appreciate your comments.

[Timothy B.]

Re: TI Problem

Barry,

Just the idea that it runs under any circumstances tells me to look for a ground problem. Double check that the amp box is properly grounded at the core support by running a seperate ground wire.

Others may have different suggestions, there is a troubleshooting guide and it may be in the archives and give you a good ideas to think about. Also, double check the wires exiting the distributor by the rubber grommet because they can bend here and cause problems.

[Mike Z.]

Re: TI Problem

Barry-
Your 66 BB should run a #231 or #261 depending on HP & date (correct Delco licensed reproduction are available on E-Bay). The #210 was used in 65 only. The #207 is the TI universal Service Replacement P/N, but also used OEM on mid-65 through 67 SB models. However, any of the P/N's you have tried should, if truly a correct reproduction (or healthy OEM) of the TI coil should work fine-the TI coils are different from the standard coil to handle the higher primary voltage delivered by the amp.
On the amp: the OEM unit/board has a two stage amplification capability, which allows starting with a full 12v., then a run capability of about 7v. based on the resistance wire within the TI harness. Some of the aftermarket modules-M&H for example (the one that looks like an aluminum plate with epoxy in the center in a rectangular shape) requires not using one of the leads in the factory harness-the one that goes to the starter, which provides the direct 12v. It relies solely on the lead from the ignition switch coming through the firewall that goes to the lead with the resistance wire in the harness-remember, no ballast resistor was used in the TI system. The net result with the M&H unit; from my experience, is the hard starting you described. I also did not find the performance to be up to the OEM board.
The Delco licensed amp boards now available are made much more similar to the original design, in that you can see all the individual components-however, I still do not find them to perform as well as the original design up-graded with better components. After we tried the M&H years ago and did not like the performance; what we did was replace the original germanium transistors (prone to failure due to heat and vibration), with more dependable and better performing equivalent value silicon transistors. A restoration service to install the up-graded amp board is available on E-Bay. If your original board is working, go with it and think about the up-grade if and when it fails-it is a better deal than the aftermarket modules, in my opinion.
Mike

[Larry T.]

Re: TI Problem

I have been told that a better alternative to the M&H product is available through K&B Special Products in Suwanee Georgia.

Supposedly the K&B board requires closer to the original .4v AC whereas the M&H board requires approximately .9v AC to operate correctly. I can not vouch for these specs, I am just passing along what I was told. The upside to the M&H is that it is practically bulletproof. I do not know anything about the durability of the K&B product.

I had a M&H in my amplifier and replaced the entire unit with OEM. It definitely has started better. I had the issue of the fire seeming to break up, it went away as well. For the record I also had to replace the TI harness because it had a bad wire in it.

Has anyone else found the K&B product to work better?

[Mike Z.]

Re: TI Problem

Larry, since I am a vendor I hesitated to indicate the K&B is the better aftermarket module I talked about previously-which I carry, as well as the up-graded original modules I talked of. That's why I simply directed the reader to E-Bay, and one would see these and a couple of other options under "T I Amplifier" and similar titles. I would be happy to answer any TI problem questions. An addition to the M&H story, please check out Corvette Restorer, Summer 2008 pages 30-31. You will see a very nice article regarding TI Troubleshooting and the M&H module.
Mike Z

[Barry N.]

Re: TI Problem

The problem turned out to be a weak magnet in the (TI) distributer. The pulse from the magnet was not enough to allow the amplifier to provide the coil with the correct signal. The wires coming from the pickup coil were also in very bad condition. The TI troubleshooting guide from the Summer 2008 Corvette Restorer was responsible for finding this problem. THANKS!