1966 Transistor Ignition

[Bill S.]

I have a no spark condition with my 327 / 350H.P. Corvette. I get absolutely no spark to the plugs with a fully warm engine. Upon letting the engine cool down completely it will restart. (it's as consistent as the day is long - always restart after cooling down!) I have installed a new coil, distributor cap, rotor, and plugs (and checked all grounds) Using the test procedure of connecting an ohmmeter between the leads at the distributor plug on cold and hot conditions I get the same readings that is 600 ohms resistance (and I do activate the vacuum advance plate) . Because the coil is new and the Magnetic pickup assembly checks out okay with the ohmmeter test --- it's the amplifier unit correct??? (The amp unit is the old transistor type that appears to be replaced once before)
Thank You
Bill Schroeder

[Richard M.]

Re: 1966 Transistor Ignition

I have a no spark condition with my 327 / 350H.P. Corvette. I get absolutely no spark to the plugs with a fully warm engine. Upon letting the engine cool down completely it will restart. (it's as consistent as the day is long - always restart after cooling down!) I have installed a new coil, distributor cap, rotor, and plugs (and checked all grounds) Using the test procedure of connecting an ohmmeter between the leads at the distributor plug on cold and hot conditions I get the same readings that is 600 ohms resistance (and I do activate the vacuum advance plate) . Because the coil is new and the Magnetic pickup assembly checks out okay with the ohmmeter test --- it's the amplifier unit correct??? (The amp unit is the old transistor type that appears to be replaced once before)
Thank You
Bill Schroeder

Bill, Since you changed everything else, it sure seems like your TI Amp is affected with heat. However, it sure seems like the typical IGN coil problem also.

I would do this.... When it fails hot, measure voltage at Coil+ with IGN on. See chart below for values. You should see +5 to +7 volts at coil+(with respect to Ground). When it's hot and failed, keep meter on it, then when cools down after a while test again with IGN back on.

The output Transistor of the Delco Amp is likely failing hot, if this turns out to be the problem.

Regardless, I'd get a upgraded TI module. I prefer the K&B version. If you decide this route, ensure your screws to mount it in the case do not bottom out and cause a "no-ground" condition. Use toothed lock-washers. See this post for more info.

Rich

[Michael H.]

Re: 1966 Transistor Ignition

Bill,

You might check and make sure you have a good ground on your TI housing. You should have a separate ground wire where the housing mounts to the inner fender, sometimes there is corrosion between the bolt and TI housing.

Mike

[Walter R.]

Re: 1966 Transistor Ignition

Bill,
Did you ever solve this problem. I have been dealing with same issue and going down the same road.

[Bill S.]

Re: 1966 Transistor Ignition

Bill,
Did you ever solve this problem. I have been dealing with same issue and going down the same road.

My resolution was buying the solid state module - see attached

[Richard M.]

Re: 1966 Transistor Ignition

Note that in my previous post, the pdf I attached was for 64,65. Here is the 66/67 version. Note coil voltage with IGN on.

[Walter R.]

Re: 1966 Transistor Ignition

Richard,
I have had problem since installed TI system that TIS put together with correct distributor I sent him and he supplied module and other parts. I would be sure that the supplied module was a solid state as it is a new over the counter module from one of the suppliers. I am at the point of replacing either the distributor magnetic coil or the module. Since this fixed your issue, which is the exact issue I am having, I will probably try the module replacement first and hope for the best.

[Richard M.]

Re: 1966 Transistor Ignition

Walter, Did you ever solve this problem? If so what was the fault? Was it the AMP?

I'd like to add your findings to my TI fault database.

Rich

[Bill S.]

Re: 1966 Transistor Ignition

It was the AMP.

[Richard M.]

Re: 1966 Transistor Ignition

Bill, yes I saw your post that you changed the AMP. Walter was also diagnosing but never came back with results.

Rich

[Walter R.]

Re: 1966 Transistor Ignition

I dealt with this issue for 3 years. In review I had my TI distributor rebuilt by TIS. I have owned the car since 1976 and had the original distributor that was given to me when I purchased the car. Distributor rebuilt by TIS and he supplied me with all parts (Harness, coil, VR, Amplifier. After installation my problems started. He did not want to help at all as his position was everything he supplied was correct. After years of trying everything it had to be Amplifier or distributor. Everything else and many other items changed several times. I purchased a $450.00 Amplifier. No change. At this point it had to be Distributor. Zip Products in Richmond, Virginia has a service department. I contacted them and scheduled an an appointment. Trailered car 1.5 hours to Richmond and dropped off. They spent many hours checking out complete system and kept me updated. Replaced distributor with TI unit on shelf and ran fine. They replaced every part on my distributor and now has run great for a year. What a relief.

[Richard M.]

Re: 1966 Transistor Ignition

Walter, Thanks for the update. I suspect the Pickup Coil was bad in yours.

Rich