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Misfires Low RPM, NO CEL

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Old 03-10-2011, 08:56 PM
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Misfires Low RPM, NO CEL

I've read most of the threads about misfires, and I'm aware of the usual suspects, but a few things are throwing a big ? my way...

2006 GT with 52,000 miles
Plugs Replaced - 35,000 (OEM)
Coils Replaced - 37,000 (OEM)
Plug Wires Replaced - 43,000 (Mazdatrix)

Had severe throttle hesitation etc., and took to Mazda (never threw a CEL) and diagnosed with tons of misfires in low RPM range (1-3k). They pulled the plugs and said the plugs look bad, so I said give her back to me bc I'm not paying $350 for you to do it.

Although skeptical that my plugs were toast after just 17,000, I replaced them with brand new ones, and the car seemed fine till the end of the test drive when I started to misfire and threw a CEL. I hooked up the OBDII reader and read Misfire in cylinder one. When I started the car again, just like that...the CEL was gone, car drove fine for a little, now its misfiring constantly in that low RPM range, but not throwing a CEL.

I would look to the next culprits, but as stated above, the coils and wires were replaced within the last 15,000 miles. Any thoughts before I waste more time/money?
Old 03-10-2011, 08:58 PM
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Right now my next move is to check the coils, but the only thing I can really think to do is switch the leading and trailing coils from cylinder one to cylinder two (i know they're technically not cylinders haha) and see if i can get the misfire to jump, but like I said, I havent been throwing a code except for that one quick time, so I really wouldnt be able to tell if it jumped
Old 03-10-2011, 09:02 PM
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Have you done a de-carbon cleaning? Also clean the MAF sensor.
Old 03-10-2011, 09:18 PM
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also, while your under there, clean your eccentric shaft positioning sensor. may not exactly solve it...but it can't hurt to spend 5 min wiping it off.

It probably is your coil's...i had mine **** out in less than 5,000 mi.

BHR is going to be shipping out a massive shipment of their coils...
Old 03-10-2011, 10:32 PM
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awesome, thanks guys... I sea-foamed her less than a year ago and I clean the MAF sensor a few times a year too...

Francesco, If i remember correctly, right? If you had coils kick the ******* that quick, I'm hoping thats my problem. I drive the car hard, hard enough to blow through the plugs in less than 20,000, so I guess that makes sense, sort of... I was just on the BHR site today pricing the ignition system, but wanted to post this before unloading the dough.

I just figured I would be throwing codes with the frequency of the misfires.
Old 03-10-2011, 10:39 PM
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What Mods do you have?
Old 03-10-2011, 10:49 PM
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Not much at this point... custom vibrant midpipe with SE exhaust, factory intake mods w/ K&N drop in, spec stage 1, and the beefier mazdatrix plug wires... everything else is either cosmetic or just top of the line pads/fluids and such... everytime I get some cash for upgrades, something goes wrong...
Old 03-11-2011, 07:34 AM
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the oe coils really are garbage. I never had misfires, but i have had 3 of 4 coils die...twice.

You could get new OE coils...or spend some more and get a coil pack with an actual warranty.
Old 03-11-2011, 05:23 PM
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is there a way i can test to see if its the coil before buying new ones?
Old 03-11-2011, 07:10 PM
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Originally Posted by flaps720
is there a way i can test to see if its the coil before buying new ones?
This is by no means 100%, but it's a start of you.

http://www.finishlineperformance.com...16-07-1793.pdf

To be honset, if you think or confirm it's the coils, I would belly up and get all four. Much cheaper from a vendor here than dealer.
Old 03-12-2011, 01:55 AM
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OMG, thank you, thats exactly what i need! And I wouldn't replace just one coil... with plugs, wires, or coils i'll always do them in sets... here's to hoping i can at least narrow down the problem... thanks again everyone, I just want my baby girl back at 100%!!!
Old 03-13-2011, 06:41 AM
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Originally Posted by flaps720
OMG, thank you, thats exactly what i need! And I wouldn't replace just one coil... with plugs, wires, or coils i'll always do them in sets... here's to hoping i can at least narrow down the problem... thanks again everyone, I just want my baby girl back at 100%!!!

Just remember these few things.

1.) That test is not a guarantee, you can still have a bad one even if it passes the resistance test.
2.) It's been seen that you can get a bad coil right out of the box(new).
3.) Misfires are USUALLY associated with high RPM's.......at least at first.
Old 01-12-2012, 08:17 PM
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Did you fix your issue?
Old 01-24-2012, 11:41 AM
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Originally Posted by Hesselrode
Did you fix your issue?

wondering the same thing. update??
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