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-   -   Mis-Firing, Need Help (https://www.miataturbo.net/general-miata-chat-9/mis-firing-need-help-8193/)

96rdstr 03-14-2007 08:29 PM

Mis-Firing, Need Help
1996 1.8L 90000 miles

The problem with the mis-firing has again reared its head. Between 3500-4000 rpms. Doesnt do it all the time. But, when it does it is in the morning when its cooler and during the day. Let me explain what has been replaced thus far....
New NGK plugs
New NGK wires
Vacuum checks out ok, no leaks
New Walbro 190lph HP pump
New Fuel Filter
Clean Air Filter

So where does that leave me? Coil Paks?????
I am not getting any codes from the ECU.

I am not bitter

DammitBeavis 03-15-2007 02:18 PM

I don't think a bad coil pack will only cause a problem in a narrow RPM range. Does it only missfire when you're on boost?

96rdstr 03-15-2007 04:27 PM

Nope, I can be running that RPM range, not be in boost and it will do it. I checked the values for resistance and voltage to the MAF and it check out ok. Wits end, I wish I would throw a code so I would know.

olderguy 03-15-2007 04:34 PM


Braineack 03-15-2007 04:36 PM

no afm though....

olderguy 03-15-2007 04:38 PM


Originally Posted by Braineack (Post 92894)
no afm though....

oops, didn't see the year(or should have looked at the screen name)

DammitBeavis 03-15-2007 05:35 PM

What's the O2 sensor say right before and right after the missfire? Might help us determine if it's a lean miss, a rich miss, or an ignition miss.

96rdstr 03-15-2007 09:20 PM

OK, through luck, I found, hopfully the problem. A wire from the CAS harness was loose. I wiggled it and the car sputtered, wiggled it some more and the car shut off. Fixed the wire, fired it up, went for a drive and no issues...Hopefully, no more issues. Thanks for the help ya'll!!!

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