I'm working on a 90 Mazda 929 that has some ignition problems. The car's heater core ruptured and soaked the passenger side floor. Shortly thereafter, the ignition system failed completely. I have pulled the engine computer and it does not appear to have gotten wet. I also checked for continuity on the wire that goes from the computer to the coil - at least it seems to go from the computer to the coil. I don't know, maybe there's an ignitor on this circuit too? Anyway, after messing with the harness and pulling / reinstalling the computer, the car now fires and runs (poorly) as long as I continue to blip the throttle. As long as I constantly make the throttle twitch from idle to slightly-off-idle, the car will continue to run. Any other throttle inputs cause it to quit running immediately.

So there's what's been going on. If anyone has dealt with a problem similar to this one, please let me know.

Also, as I mentioned earlier, the engine computer appears to have remained dry. However, I still suspect that it was damaged. Do any of you guys know how to get another computer for this car. I can't seem to find a used one at all.

Thanks,
Brian

 

Just a quick update in case anyone is following this...

I can now keep the car running while blipping the throttle like before. The ignition circuit is in tact. I put a timing light on the car and can see that the timing is pretty consistently staying at 10 deg advanced. The timing doesn't cut out at all.

So it looks like I'm probably not getting a pulse to the injectors. I can't think of a way to test that other than to connect my 30-year-old oscilloscope up to some of the injector wires haha. I'm not sure I want to subject my o-scope to that.

I did find a computer for sale for $29.00 and I'm going to scoop that up. Hopefully it is actually the computer that's been causing these problems.

 

Can any of you guys tell me where the ignitor / ignition modele is on this car... or where it is on an earlier model car?