My car is an original 1969 K66 car. Years ago I went with a msd 6a box. I've since decided to go back to the t.i. system. Bought new t.i. harness, the harness to the amplifier box, and new solid state circuit board. I now have no spark. I have 12v on both pink wires with the key on and when cranking, grounds good at both the rad support and amp case. Have continuity from coil negative to rad support ground. I even did a dedicated amp case ground, just in case. Pick up coil ohms at 580.What I found going through diagnosis is leading me toward the module. I have another new module that I have not tried yet. Car did run before removing msd and installing t.i. parts. Any thoughts?

 

You can verify the pickup coil output with a meter- set on millivolts, One lead from the meter to each of the distributor leads. Crank it and you should see a small output on the meter. Past that, I'm thinking your new module may be toast.

 

Have you followed the flow chart in the GM service manual?

That is how I figured out my problem with my 68 ti system.

bigredbrad

 

Correct TI coil?

 

It is not the correct t.i coil, although I do have the original 69 coil. Short story long, engine has a 67 435 intake manifold and stock coil does not fit inside 69 distributor box and a 67 box just doesn't look right. That being said, Paragon's website states "We recommend installation of our 1380 T.I. amp module for 2 reasons. First, you can use any stock Delco coil rather than purchasing an expensive T.I. coil, and second, because the solid state design virtually eliminates failure commonly associated with the original circuitry due to moisture intrusion." The instructions that came with it say "Also provides satisfactory performance when used with point type coils or aftermarket performance coils." I'm using a msd 8207 coil.

 

So far, I've done the basic power and ground checks using the wiring diagram from tispecialty.com website. I'll dig into it deeper on Saturday.

 

I ohmed the pickup coil and it is 585 ohms which is in spec. The car ran for years with the msd box. It doesn't have any spark since removing the msd and installing the new t.i harnesses and module. Same pickup coil and coil as before.

 

O.k. Good luck

 

Thanks Calo. Somehow I find working on C5's and 6's easier.

 

My experience with upgrading to a solid state board.....

It did start after installing the SS module, however with much difficulty. The difficult starting persisted for several months, getting worse as time went on. Then I was determined to find out why.

Temporarily replaced the T.I Amp with a HEI module. This worked great with one odd side effects. Starting was instant, better than with the old transistor board.

The odd side effect was that if I used the power windows and held the switch on momentarily when the window was fully up or down, the engine would quit, or stumble if you released the PW button immediately.

Reason, the "Pink" wire did not provide enough power to drive the HEI module. A relay tied to the horn relay12v fixed that. Pink wire used to triggered the relay.

Now back to the SS module. Reconnected the SS module, now very difficult to start. Diagnosis, "no spark while cranking". However when/if you got it started it worked great.

The FIX !!
Since the HEI module does not use the 12v wire from the starter, and the T.I. does, I disconnected the 12v wire from the starter to the T.I. harness.
Instant success. It now starts better than it ever did before. Starter barely engages and the engine starts.

I have no idea why it won't work with the starter 12v wire connected. At this point I don't care. It works so good this way.

I also still have the relay installed to provide 12v to the TI harness.

 

Because if you dont have a starter with the switched terminal output it will pull the TI supply voltage to ground.

Anyway, if you have problems with the TI system, you have to understand in detail how it works. Electrical skills are requiered.
If not, all you can do is to exchange parts and hope it works.

I assume you are using the right TI-Distributor? And it puts out the requiered voltage ripple when it´s beeing turned?
Please pull the plug from the module an measure there.
You also may measure if the pink wire there receives 12V when ignition is on.

Then it does matter how this coil is connected (polarity).

The TI can drive any coil, this doesn´t matter. But it´s important to
know, that the coil has to be connected directly to ground and is supplied by a resistor wire from the module.

If the module is supplied with ground, 12V and the ripple and does not feed the coil, we can assume it´s defective.

 

Car is an orignal TI car and has original starter and 1111928 distributor. Car ran with original t.i setup before converting to msd 6a years ago. Car ran with msd box and msd coil until changing to new parts last weekend.

I do have 12v on pink wire at the connector from the ignition switch and from the starter. I have ground from coil negative through the harness to the radiator support. Good clean ground on amplifier housing- even went as far as giving the case its' own dedicated ground wire to the cylinder head. I removed the original t.i harnesses and amplifier circuit board and replaced with new Lectric Limted harnesses and solid state module because original owner changed the 3 wire plug to allow the t.i. module to be removed as an anti theft device, plus them being almost 50 years old.

When you say pull plug from module and measure voltage there, I have the ss module out of the amplifier housing. with the key in the run and crank position I should see 12v on the pink wire? Black should be ground to the rad support and to the coil negative. Coil plus should see how much voltage because of the resistor wire? T.I. coil measures 585 ohms with no no continuity to ground.

 

Usually you measure ~6V at the coil with ignition "on" and motor nut running.
But I don´t know if that´s still the case with the newer solid state modules.

I maintained the original TI system in my ´69 for years, then switched to (hidden) MSD because of better performance.
But did also replace a faulty TI System in a ´68, complete with module and harness from lectric limited, this worked without any problems.

Last thing you have to check is if the ripple is received at the module, shoud be on the gray wire. You should have an oscilloscope.

Btw: you have wired the module right inside the housing?

 

I connected the leads per the instructions.

 

With the key on, what voltage are you seeing at the coil C+ terminal? Going by memory, there's two ballast resistors in the circuit (with about a total of 1.3 ohms IIRC), and you say that the coil you're using is point 585 ohms, you should see about 4 volts on the C+ terminal. Are you getting a reading approximating that?

 

69427, I don't remember the voltage at coil +. I'll check tomorrow. There are no ballast resistors in a t.i. car. It is done with resistance wires as part of the t.i. harness, which is new. The pickup coil inside the distributor resistance is 585 ohms, within the spec of 500-750 ohms.

 

This manual will walk you through the diagnostics of the system.

1969 Corvette Transistor Ignition Service Manual

 

Friend, I'm trying to help you out here. Please don't be difficult. Those lengths of wire are purposely resistive. Hence they are resistors. Their function is to limit the maximum current through the ignition coil, the very definition of an automotive ballast resistor. They are ballast resistors.

What's the resistance of the ignition coil? When you mentioned "T.I. coil" right after talking about the coil C+ voltage above, I assumed you meant the ignition coil. The (ignition) coil resistance is needed to calculate what the C+ voltage should be with the key on and the engine not turning.

 

Sorry if you took what I wrote the wrong way. To me a ballast resistor is a resistor encased in a ceramic housing like what mopar uses. I do appreciate everyone's thoughts, ideas, and suggestions. After a cup of coffee, I'm out to the garage.

 

After going through the wiring schematic, everything checked out. I tried it with the t.i ignition coil and still nothing. Nothing to lose, I replaced the new module with another new module. Car started faster than I can ever remember. Defective module? reinstalled msd coil, tried to start, ran for a split second, and now back to no start. Installed t.i coil again, no start. Moral of story- contrary to what "tech" people say, these ss modules appear not to work with a non t.i coil. An expensive $450 mistake.
In order to fit the t.i. coil inside the distributor box, I need to raise the box about 3/4". I can either put a spacer between the box supports and the intake manifold or lengthen the supports 3/4". Or remove all the t.i stuff and update to the latest msd box.