Amur_

This was posted to rec.autos.rotary. I've spent the last little while searching here to try to offer him clues/answers, but everything I find merely says, 'The tach runs off the trailing coil..' I need a little more than that and I don't have all night to search for it, so pardon me if this is an easy one -> I'm an FC guy.


I've replied that he's checking for spark correctly, and that I've posted his question here.

Who's gonna be the first to step up?

MosesX605

If it's an 80, the tach ran off the leading coil, so if the leading coil or ignitor is bad, that would be the source of the bad running and no tach.

Amur_

He says that the ignition sys is out of an '83... So the tach's off the trailing coil, right? Regardless, he says that *none* of the plugs are firing.

hornbm

id replace the coils and ignotors, and check the wiring while your at it, make sure nothing is shorted out. There arent really that many wires to the ignition system

MosesX605

It's easy to leave the tach signal on the leading coil when you swap the dizzy over. I did. As for the rest, I'm with hornbm, check all the wiring and make sure that both ignitors and coils are working.

Swamp Buggy

Hi Folks, I 'm the guy with the car that is doing this.

Here is where it's at; I've replaced the coils with ones that i know are good. When i replaced the ignitors, it worked for a second. I could hear that it was all going well, then it was back to what sounded like one rotor not getting any spark.

Is there some bad component that might be frying the ignitors?

All the wires were working fine up til the moment that it cacked. So everything is in the right place, the same place it has been in for the last 8 years.

Next step will be to test the ignitors on the ground, with the switch lightbulb and all. At least if i know they are good, then i can move on.

I've checked for spark, and now i'm not getting any spark.

I also tried running from the coils right to the leading plugs (I've heard that this can be done) and it seemed to fire./.. but the plug wires aren't long enough; ie: bad connection.

Xavier8

Have you replaced the plugs yet? After I flooded the heck out of my motor the plugs looked perfect but were horribly fouled. Just replace the 2 leadings and try again.
Other suggestions::
Switch the ignitor leads and the coil wires from each coil into the distributor. Then you can see if its coil problems. You have to switch both ofcourse or your timing will be off.
Have you replaced the cap? Could have a crack.
Are you sure all plug wires are intact?
I have had ignition problems, and as a check I usually switched the wires to the ignitors and swapped coil wires and bam, engine started in leading plugs alone. Don't fret about your trailing plugs, your engine doesn't really need them to spark to run right. Concentrate on your leading and you should get back on the road. As another check, if none of that works, swap the ignitors themselves.
But first, buy new plugs from advance auto parts or whatever you have in the area. I don't think autozone carries them, but I know advance usually has some in stock. Good luck.

eXpLiCiT

Check your control modules in the distributor.

Swamp Buggy

OK so far i've replaced the Ignitors- Plugs - Coils - Cap - Rotor..

The best results i've got are from replacing the Ignitors, and then it works for about 10 seconds... and the same problem.

I have a psare distributor, but i can't sdeem to pull the one that is in there out.. it is seriously stuck.. Any ideas on that?

Swamp Buggy

Okay , now i've replaced the ignitors, entire distributor, both coils, all the plugs, and checked all the wiring.

I've got the Tac to run, but it still seems the plugs are not sparking.

I:ve also checked all my ignotors on the ground with that 10W light-bulb set-up it descibes in the Haynes Book. And they all seem to work fine.

Next step is sand the housing of the dizzy so that there is a good ground contact with the ignitor boxes.

Jeff20B

iTrader: (13)

The ground contact comes from the two screws that hold the ignitors to the dizzy housing. If it has any contact from the aluminum backing plates of the ignitors directly to the dizzy housing, it's purely coincidental. Before I tell you the reason why, have you been using any heat sinc compound? Also, how is the voltage to the B terminal of the ignitors and + terminal of the coils?

Use a plastic hammer to tap the dizzy upward.

Swamp Buggy

I managed to get the 'dizzy' out , and put in one that i know was good. There is power getting to the coils, I've checked. I've replaced the entire ignition system.

I get this: Hard Hard start, flooding, no detectable spark.

I did manage to get the Tac working.

Jeff20B

iTrader: (13)

It could be bad spark plugs. I swapped some and was able to start one of my engines within two seconds of cranking. This is compared to several previous cranking attemps. Some with gas fouled plugs, some without the plugs in it (to blow the fuel out of the plug holes). Even after cleaning the fouled plugs, they still didn't perform as nicely as the totally dry (old used) ones I had laying around.

Swamp Buggy

Hey i was just scanning the net and noticed that i never told you guys what was teh problem and how i fixed it.


I found out that the fusable links on the Firewall had been grafted on out of another wiring harness, and they hadn't done that great a job.

So Cut Cut Cut , Crimp Crimp Crimp.... and Drive Drive Drive...

car is put away for the winter though... if Winter ever gets here.

Thanks for all the help.. It's always something stupid one doesn't think of.. at least in the process i replaced the entire ignition system with all fresh parts.


Happy New Year

Jeff20B

iTrader: (13)

Closure is always nice. Glad it worked out in the end.

Amur_

Congrats you! Way to go! I'll see you on the road when you bring her back out.


Btw, you coming out for this?

https://www.rx7club.com/showthread.php?t=379250

https://www.rx7club.com/showthread.php?t=382403