Anyone successfully got a tach to work on the 77-78 hybrid ignition system? (1 Viewer)

[DougAustinTx]

I spent the day trying to get both an analog and digital tach to work on my "spare" 2F engine that has the hybrid points-igniter system. I tried getting the signal off the coil at the negative terminal, and also at the distributor lug for the points. Could not get a signal at either point. I am now thinking I will have to use an inductance type tach that wraps around the #1 spark plug wire. My '79 2F which uses a pickup coil in the dizzy that is actually in my 40 has no problem working the tach at the usual pulse point at the coil negative. Has anyone gotten a tach to work using their original Toyota '76 '77 '78 hybrid points/igniter system ? (not sure when the hybrid system began and ended). If so, please describe the solution.
Thanks,

Doug

 

[SteveH]

'78 was fully electronics and some '77s were. My 1/76 FJ55 had the hybrid points system. I wonder why (electrically) you're having problems? One would think that the coil negative terminal wouldn't care what fired it, so to speak. You have my sympathies in trying to figure this one out!

 

[DougAustinTx]

Thanks Steve. Unlike most of the other models, the wire to the distributor (points) doesn't come from the negative coil post, it comes from the igniter circuit. Thanks for the post. I kind of like the hybrid points/igniter system, but this has really stumped me.

 

[thorslc1977]

I am the original owner of my 77 fj40. Original ignitor/coil still in place. Never had a problem with an analog dwell/tach meter. I use the the positive lead to the negative lug on the coil and the negative lead to the negative post of the battery. I did try a digital meter it measured rpm's from 500 to 10,000 but 0 was 500 so you had to add 500 to whatever reading you would get.

 

[thorslc1977]

I am at work now but I will take a pic of my wiring. I can't remember where wire comes from that goes to distributor. I do have the City Racer new distributor in but tach works with old and new distributors.

 

[DougAustinTx]

Thanks Thorslc1977. So you are talking about using a real dwell/tach meter (handheld type). I still have one of those and will give it a try, but I am trying to get an in-dash round faced 2 1/16" style of tach to work. I sent back the digital tach I had tried and just received the new replacement and will try it out today.

 

[thorslc1977]

Yes, old fashioned hand held dwell/tach meter. Bought right about when I got the 40. I know it cost less than ten bucks back then. I want replace it. It is so worn you have to hold it level as the play in the needle will show slightly different readings if you tilt it. It is the best tool for a tune up on this ignitor/coil setup. By the way the City Racer distributor is a plug and play with this set up.

 

[thorslc1977]

You are right wire for distributor comes from ignitor. It goes into the harness then exits harness close to distributor.