MicroSquirt.com read only forum (Jan.15,2018)

I have been running EDIS for 3 months now, with no problems. After fixing my air conditioner this weekend, I seem to now have an ignition problem. It does not seem to be load related. Basically, after the air is on for a few minutes, I get random misfires from 1500 to 2600 rpm. When it misses, the tach drops out completely. After turning the AC off, the problem slowly disappears. To me this almost has to be underhood heat/vibration related. I double checked all wiring connections, thinking maybe I pulled on one while working. I have a spare EDIS module and coil I will likely try. I am still not 100% sure the AC has anything to do with it, but there definately appears to be a correlation.

My question is, is there any way a MS problem could cause the coils to not fire with EDIS? I was under the impression if there was any problem with the SAW signal, it would just revert to base timing? As long as I know the problem has to be under the hood I can fix it very quickly. Just need to know if the MS had an intermittant problem if it could cause this. I know when I was running tfi having the predictor algorithm wrong caused a jumpy tach and missfires.

I can’t speak for your situation, but the air conditioning vents/flaps runs off the engine vacuum. You may have created a leak when you fixed the air that wasn’t there before.

Bill Struble
Posted by email.

wes kiser wrote:My question is, is there any way a MS problem could cause the coils to not fire with EDIS?

We've not yet found a way to stop the EDIS firing.
If you don't send or send an incorrect SAW it fires at the previous advance for 5(?) sparks and then reverts to 10BTDC base timing.

So you problem must be related to VR sensor, EDIS, coil somehow.

James

That was what I thought. I put in a different EDIS module last night after I checked all the wiring connections, and it did not miss on the way to work this morning. I will likely know if it fixed it this afternoon, as it did it fairly predictibly yesterday.

No missfires in 2 days. Apparently the module was bad. How vibration sensitive are the modules? I have mine and the coils mounted directly to the engine (on the factory cars the coils are mounted to the engine). Could the mounting scheme be what killed it, or could it just have been it's "time"?

wes kiser wrote:...How vibration sensitive are the modules? I have mine and the coils mounted directly to the engine...

EDIS modules are factory mounted in ways to keep them cool. On the engine with the coils may not be good for them. For that matter the coils are not directly on the engine but usually on a bracket that allows airflow around them.

FWIW,
David

I used the factory coil bracket. It seems as if moving the module would be a good idea.