jonfkaminsky

I observed the engine compartment while the engine was running and did not see any sparks or arcing. This was a pain because of the inability of the car to stay running. I did notice that overall, the car reeked of running rich.

I bought two coils for $60 per and will replace them anyway. I checked all the wire connections on the dist and the coils. All are tight and I seated them correctly the first time.

Garrett-
Yes It was running fine and now its broken - except the initial problem was all the warning lights coming on and lodging 1134 and 1234 fault codes, although the car ran fine if you could deal with the racket coming from the warning buzzer. But now the issue is hesitation and stalling.

After replacing the battery ...no change. Replaced dist caps and rotors...no change. Replaced spark plugs and wires...problem solved and ran great for two weeks until the hesitation and stalling began. Then replaced DME relay..no change. I have coils left. After that, if no change, I will take apart the induction system to make sure that is operating correctly. If nothing discovered there, it will have to go in as I can do no more.

garrett376

Did you ever replace your O2 sensor during all of your parts replacements? At least check the plug to be sure the pins didn't get smashed?

jonfkaminsky

Garrett-
I did not replace the O2 sensor. I was careful when I unfastened it from the catalytic converter. he O2 sensor was checked out by me a while back and was in spec. Dealer claimed there was nothing wrong with it as well (which doesn't mean anything).

I did purchase the cylinder head temp sensor a while back but did not install it. I did replace the oil temp sensor (the one that controls the fan), so it would make sense to get the O2 sensor done too for completeness if nothing else.

My plan this afternoon is to take some continuity readings on the Hall signal sensor, and replace the coils. If I get real ambitious I may do the cyl head temp sensor. Then I will be out of new parts!

Jon

garrett376

If it is running rich all the time, another consideration is your fuel pressure regulator. I assume it's similar to other cars, since on my truck that is fuel injected, the fuel pressure regulator died causing it to run rich all the time - the engine computer kept saying the O2 sensor was off, but the sensor was fine. Replacing the pressure regulator fixed the problem.

So if there's a way to test this, or swap with another - it might be your key - as long as you seem to be running rich all the time. If your O2 is fine, but you have too much fuel pressure, you'll run too rich, and your engine will have trouble running - your problem sounds just like what my truck did. Sounds like a very good possibility, and it hopefully is not too expensive - wasn't on the Mazda Navajo....

Hang in there - hopefully we can figure this out!!

Colin 90 C2

Garrett may be correct about the fuel pressure regulator. I had to replace one on mine. The telltale sign was that the cat was red hot while the car was idling. The diaphagm was leaking and actually leaking fuel onto the top of the engine. I don't think the part was too expensive and the changeout was easy, once you got the fan out of the way.

Good Luck,
Colin

jonfkaminsky

Well sumbitch...coils went in and car is running great again. I also checked all the wire connections on the dist caps- all were good. So....it would appear that the coils were it. I'll keep my fingers crossed!!

Thanks to all who helped out with the advice and encouragement.

Jon

Bill Gregory

FWIW, I replaced both my coils and coil wires last year as preventative maintenance, as there have been other reported problems with coils/coil wires.

Jon, did you talk to the folks at Magnacore? What did they say about their spark plug ends sticking out?

jonfkaminsky

Hi Bill-
Yes I did talk to them. same info they gave you. Their connectors are longer than normal, so you would have to be okay with not running with the heat shields in place. I went with the Beru set for $385 US. Maybe in the future- but I was happy with the quality of the Beru - although I wish they were blue.

By the way, Bill, where did you get your RS heater blower bypass? Does that source still exist, or should I look up Thom for his carbon fibre version?

Bill Gregory

Jon,

I actually bought mine used. The part has been in production as a 993 part, however, I heard in the last week or two that they may have gone out of production. Gert in Belgium has been one source, and could be checked (even though currency conversion rates aren't in our favor). Schatz Motorsport may be another source. I know someone had posted the part number previously in the forum.