1966 L72 TI ignition question

[Donald H.]

Can someone recommend a aftermarket replacement coil that is correct for the TI Ignition?

I'm helping a friend who is having trouble with his 66 425HP car. The problem is the car runs great for about 10 minutes. After that, it will stall and die. But it will start right up. So we are kind of thinking it isn't a heat related issue (e.g. percolation, hot coil or similar).


What has been done:

- Replaced the TI Module board with a new K&B board installed. Did not solve the problem.
- Replaced the carburetor. He had recently installed a freshly restored date correct carb and suspected it, but put back on the prior carb. Did not solve the problem.
- Replaced premium pump gas with Sunoco Racing Fuel. Did not solve the problem.
- Tested the coil secondary. Per the Service Manual the reading should be between 8,000 and 12,500 ohms. My friend said he gets 14,000 ohms. Neither of us really know what this means?

What we plan to do:

Replace the current NOS coil

Take apart the bulkhead harness connector and clean and spread the pins. The car has about 350 miles since restored and the harness was a new Lectric Limited harness at the time.

I also read that there can be issues with the fuel cap not venting properly, have not checked that.

Thanks,

Don

[Joe R.]

Re: 1966 L72 TI ignition question

Hi Don,

Try this page from the TI Specialties web site:

http://www.tispecialty.com/articles.htm

Good luck!
Joe

[Anthony S.]

Re: 1966 L72 TI ignition question

If the sock on the sender in the fuel tank is all clogged up, it will cause this behavior.
It may be even be clogged and not even look like it is clogged, so need to check carefully.

[Donald H.]

Re: 1966 L72 TI ignition question

Hi Don,

Try this page from the TI Specialties web site:

http://www.tispecialty.com/articles.htm

Good luck!
Joe

Thanks Joe. I was aware of Dave Fiedler's stuff. Just hoping someone like NAPA or Rock Auto would have something that would work OK.

[Donald H.]

Re: 1966 L72 TI ignition question

If the sock on the sender in the fuel tank is all clogged up, it will cause this behavior.
It may be even be clogged and not even look like it is clogged, so need to check carefully.

OK, thanks.

[Richard M.]

Re: 1966 L72 TI ignition question

Don, 14k ohms on the output is reasonable, but not a complete indication of a good primary. TI coils (eg the 263/207) should read apx .5 to .7 ohms on the primary (+ to -). Non TI coils typically 1.5 ohms or so.

You can use a non-TI "ballast resistor required" type coil with TI as a experiment. Napa IC12 or equivalent is fine. You just won't get full 30Kv at the output. I've been running a IC12 in a '67 L71 for quite some time. Runs fine.

If it dies 10 minutes and restarts immediately, this almost seems like fuel to me. My first thought would be a bad fuel pump.

If you've proven it's not a fuel issue....Check for spark using a timing light with induction pickup. Put it right on the coil HV wire and you should get sequential flash at crank.

With engine stopped and ignition on, with a meter check that you have 2.5 to 4.5 volts at the coil+ with respect to coil-(ground). If not move the meter ground lead to the engine ground to verify. If you get variants, check ground at the TI Module and rad support. If in doubt, add a ground to the module and directly to coil-. Coil- is hard grounded from the module case/rad support in the TI harness.

Follow the CSM "Circuit Resistance Test" procedure here for other coil voltage tests.

http://www.tispecialty.com/articles/66-71.pdf

Distributor pickup coil should read 500-700 ohms, disconnected from the harness. The pickup coil wires are prone to connection problems and wiring faults. Wiggle things around when testing with the meters.

Rich

[Donald H.]

Re: 1966 L72 TI ignition question

Thanks Rich, good info and we will certainly try all.