I'm attempting to replace an old points-style ignition (which worked fine) with the correct TI ignition in my 1971 LT-1 and am unable to get the car to start. I AM getting a spark, albeit an intermittent one. The car sounds like it almost wants to start but never completely engages.

Here are the installation/troubleshooting steps that I took:

1. Set engine to TDC where rotor is pointing to cylinder wire #1 and make note of the rotor position.
2. Install TI distributor in exact same position (rotor on new distributor pointing in the same direction as original).
3. Install correct TI coil.
4. Connect all TI harness wires correctly (double-checked).
5. Ensure good ground from TI harness to radiator. Confirmed by checking continuity from (-) side of coil to ground.
6. Plug TI harness into amp pigtail.
7. Confirm 3.5v across coil with ignition set to ON position.
8. Confirm 7.8v from TI harness PINK wire while ignition set to ON position.
9. Confirm 11-12v from TI harness PINK wire cranking (power coming from starter solenoid).
10. Confirm 583 ohms across TI distributor leads (through full advance travel).
11. Confirm spark on cranking.

When cranking, the car sounds like it almost wants to start but never quite gets there. I'm positive that I installed the distributor in the exact same position since I used the original rotor-position as a reference point. I've tried advancing/retarding the distributor to see if that makes any difference (it doesn't). I should note that unplugging the TI harness PINK extension from the starter solenoid seems to help somewhat, but it still doesn't start.

Here's a video that I took showing the intermittent spark:

https://drive.google.com/open?id=1HW...Zwx14yeTkHgU7P

I've read a number of other posts to troubleshoot this, but am at a loss at this point. Could it be the TI amp? It is an original board from another car believed to be working properly when removed. I AM getting a spark, but it doesn't seem consistent. I can always revert to the original ignition system, but I'd really like to get the original TI system working properly.

Any advice or troubleshooting tips are appreciated!

 

When I upgraded my amp to a new solid state board, I had starting issues. Disconnecting the wire from the starter made a great improvement.

I also used the main power (pink) wire to energize a relay that put 12v from the horn relay to the TI harness. After that I had great starting and an improved spark.

 

Yeah, I saw your post. I've tried disconnecting the wire to starter solenoid but it still doesn't start. I know I'm getting **some** spark, but obviously not enough continuously for it to run.

I had a though today and ran the ground wire UNDER the amp by the grounding tab to be sure it was making solid contact with the back side of the housing. Unfortunately, this didn't appear to make much of a difference.

Question - is it possible to install the distributor shaft in 180 degrees incorrectly? The rotor appears to be able to mount in 2 directions. I didn't play close attention to the original distributor to ensure that the rotor was facing the same side as the shaft dimple. The only thing I did was mount the rotor on the new distributor and ensure it was facing the same direction as the original one.

 

The dimple on the gear MUST align with the rotor tip when assembling the gear to the shaft. Otherwise, the rotor will be "out of phase."

 

I figured it out - posting here to help anyone else running into similar problems where all the tests check out. I unplugged the TI harness from the amp to inspect the terminals, and while doing so added some dielectric grease for good measure. Once the terminals were generously covered, I plugged everything back together snugly and voila - engine started right up. I suppose that the intermittent spark condition was due to a poor connection -- just enough to pass the continuity/voltage tests, but not enough to properly run the amp. It seems the TI systems are especially finicky with janky connections, so you really need to ensure that all connections are 100% clean/solid (including ground).

Edit: also want to mention that I did NOT need to remove the PINK pigtail from the starter solenoid. All connections are factory spec.

 

I had the wire connected from the starter for over 40 years with no problem. When I upgraded to the new solid state amp, that's when I had the starting issue. Disconnecting the starter wire fixed it.

Still doesn't make sense, however as long as it works, I won't connect it. Maybe I have a strange amplifer.

Good that you got yours figured out, that could have been tough to find.