Random misfires

[SmokedSS]

I continue to have random misfires with my stage ll Whipple. I am on 2nd set of spark plugs Shell 93 fuel. I have done a crank relearn several times. Plugs are gapped per Whipple. Any thoughts on what my problem is? Anyone else have these problems?

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[5.O]

Same is happening on mine. Just changed the spark plugs and still get random misfire sometimes. I got no idea what's wrong with it.

 

[SmokedSS]

Finally able to check codes,, This time 4 codes in this order 0300, 0302, 0300, 0302. I will look at the #2 plug and see if I see anything. Any thoughts???

 

[Tommy V]

Check the coil for the cyl misfiring,and also with all those misfire codes i would check and clean the maf sensor.U can also move the number 2 plug and coil to another cyl and if the misfire moves u have your problem,if not check maf and vaccum leaks first.

 

[SmokedSS]

I need HELP bad

OK I removed #2 and 4 plugs and they looked good and were @ .028 so I swapped the plugs only. Drove car and it is missing bad and low on power with PCM cleared and a crank relearn. When I ran it up the check engine light came on so I checked to see if codes moved and they were still showing P300, P302 and now P616 which reads multiple misfires on start-up.

So I now swapped the coils from #2&4 and duplicated test drive. Car missed badly like before and check engine light came on when I got down on it. This time codes read P316 and P300 again but the P302 n ow changed to P301. I checked and cleaned the MAF, checked for leaks and everything looks OK.

What is going on here.

Any help would be greatly appreciated!!!! Do I have a bad tune? Fuel? Fuel injectors????

This may sound crazy but seems like the CHT are also a little higher now. Only recent work on car was to install a Mishimito radiator???? System is bleed and no leaks.

 

[SmokedSS]

Looks like I received bad info on cylinder numbers :( If passenger side is #1-#4 starting with #1 at radiator then looks like I have been swapping 1and 2, not 2and4 so maybe a bad coil? Fingers crossed with now try another coil. Is the cylinder location 1-2-3-4 passenger and then 5-6-7-8 drivers side?

 

[SmokedSS]

Swapped out coils and car sounds much better. Weather just got bad so I can't test drive.

 

[Dntalman]

If you have longtube headers with 02 extensions it could be that. I have a extra set brand new if you need them. Pm me if you think that is it.

 

[Plimmer]

In for results, I'm also getting random misfires, turbo car. Starting to think its occurring at cruise, and not at WOT.

Might fiddle with the misfire monitor settings, just make it run at higher rpm

 

[SmokedSS]

No long tubes,

Definitely a bad coil for me, car is now running much better and smooth with no missing, still need to run it through a couple gears to see..

 

[MikeyPee]

Looks like you figured it out . Yes, 1-4 are on the passenger's side, and 5-8 are on the driver's side, cylinders 1/5 being closest to the radiator

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