Tyrel B

So I've got my car put it all back together and have ran it a few times for 10 to 15 minutes a piece. It is a factory 427 435 horsepower. All the wiring looks correct as far as I can tell. I replaced the transistor ignition unit with a newer electronic modern unit. I change the starter to a powermaster 9202 with three terminals, one for the resistor wire. The coil is a new unit for transistor ignition from Zip I belive without looking at recipts, ordered alot of parts lately. When running the coil will get quite hot, you can touch it but not hold your finger on it for really any amount of time. I haven't took a temp reading with a electronic thermometer yet, but it's hot. It seems to run fine but just wanting to check. Its defintly not from engine compartment heat because other parts around it are not near that hot, and there's no hood on the car yet. I checked with a volt meter the voltage at the coil, between the coil pos and neg, but can't recall the exact numbers without checking again, I believe they were 9.something while cranking and 4.somthing with just key on, maybe around 4.3ish. Just looking for input. Thanks

MelWff

I doubt the coil should be getting as hot as your describe.
What is the voltage at the positive terminal with the engine running?
Did you wire the system per the diagram on this link?
https://www.tispecialty.com/articles/66-71diagram.htm
Try the resistance test in this article and note the coil operating range.
http://www.tispecialty.com/articles/article4.htm

Tyrel B

I will check the running voltage tomorrow and check the coil resistance. Thanks for the links. I didn't rewire the car so it is still the way it was, it's looks correct, but I will use that diagram to check it all over. The coil that was on it was some other brand, external resistor I believe is what it said on it, but it looks like all the TI wiring and such is right. I know the distributed is 100% correct. I have gone through it already.

Tyrel B

The car was wanting to run rough at idle and higher RPMs, I was thinking it was the coil, but after checking over all the wiring, looking at the voltage and resistance of the coil everything seems correct. So I ended up swapping out the new circuit board style transistor amplifier for the 100% original transistor ignition module that came out of the car when i started the project. It fixed all my running problems. Has anyone else had issues with the newer style modules? I thought they were supposed to be better than the original Style. Maybe I just got the one bad one. Seems to be my luck.

69427

Glad you narrowed the problem down to a bad board. Hopefully the vendor will stand behind the product and replace it.

Regarding the coil, it will get warm in TI applications. With a primary current of (IIRC) about 7-7.5 amps, and about a half ohm of primary resistance, there's about 25 watts going on while the key is on. The on-time duty cycle will drop once the engine is running, but the voltage across the coil will bump up a bit due to the alternator voltage, offsetting the lower duty cycle.

It's not a terribly efficient system, but given the vintage of it, it was a reasonably clever design for its day.