I think I'm loosing my coil?

[TurboDuane]

I'm certain it's not the injector harness, as when this happens, fuel seems to still be flowing. When it happens at idle, there is a strong smell of fuel. On occasion when it happens it will load the exhaust with raw fuel, that will give one hell of a backfire when the spark returns.

I am a little worried about the ECU (Link) but am really hoping that isn't where the problem is. I'm certain the ECU is grounded, but need to check the engine grounds. But if I had Engine ground problems, wouldn't I have some other signs? Like RPM guage being sparatic and such?

[TurboDuane]

For archival purposes only, I thought I'd add the below information:

Well, Sunday I ran down all the wires and un-connected and re-connected every connection including the Link, I also changed out the wrecking yard CAS for my old one; just to see if my original problem was the coil. I got to thinking I might have replaced a good CAS with a bad one. I also got to wondering if my Keypad may have been having intermitten connection issues with the serial cable, so I unplugged the keypad.
5 days now and the car hasn't acted up. So today I plugged back in the Keypad and still no issues. I'll give it a few more days, if it doesn't act up further then I'll call it good. If this is the case then I'm going to say my original problem was probably the Coil, but I replace the CAS with a wrecking yard CAS, that was bad, making my problems actually worse. I then replaced the Coils & igniter, but still had some intermitten issues. When I went back with my original CAS and a new igniter, then the car was well.
Problem is, It could have been a bad connection that I stumbled accross but didn't see it.
After another week I'll report back.

[TurboDuane]

Final report, my car has run over two weeks now without an issue. That is until I plugged in the head unit for the Link. within a day the car shut down on me, then came back to life. I'm certain my intermitten power loss is related to a short in the serial cable between the head unit and the Link. For reference below is a list of my steps:

• Car would run on 2 cylinders from time to time, reporting 200 rpm, or at least half what it should have been

• Car would occasionally loose all spark, killing the car, most of the time spark would come back before car came to a stop

• Replace CAS with Salvage yard CAS

• Problem got worse, so went back to original CAS

• Replaced Coil/Igniter, thinking it was the source of the shutdowns. Gas mileage increased, but problem persisted

• In despiration, I unplugged the Link's head unit

• drove a week with no shutdowns, but had some occurance of running on 2 cyl.

• Exchanged Salvage CAS for another Salvage CAS at Mazda Heaven, and installed it.

• Reset base timing.

• 2 weeks and not one mis-fire, no shutdowns, no running on 2-cylinders.

FIXED
For grins,

• I plugged the Link head unit back in

• within a day, the car shut down twice

• Next, replace the serial (ribbon) cable to the head unit

Hope this helps the next guy.
TD

[TurboDuane]

OK, the problem wasn't fixed as previously reported. The problem has been coming and going so much I thought it must be related to my teenager.

However, the problem has been getting worse, so I took the computer apart, again this weekend and solder'd some more on the computer, even though I couldn't identify any problems. I also re-did some wire connections to ensure a good connection. Saturday and Sunday car ran fine, then Monday came. The car wouldn't start on most attempts, then when it did it barely ran.

Finally, its acting up consistantly enough to troubleshoot it. Since the problem was with one of the coils, and the CAS send the message to the computer, I figured it had to be a problem within the computer concerning these. So I broke out the schmatics, and figured out which pins on the link concerning both CAS signals, and both igniters. I re-soldered those pins to the Link, then followed the circut boards lines and re-soldered each connection on each associated line.

I'm apparently better at soldering than I thought, because I was worried that I would ruin the Link, but WHOLA, the problem is completely gone! At least for the last two days, more time will tell, but it's looking good.