spent a bunch of money on it already still yet my misfire continues to be there. It's probably something stupid, but I pulled plugs all looked good, but they have maybe 1,000 miles on them so no distinct color on them. My friend seems to think got a bad fuel injector from the way cylinder 5 looked and 5 is giving me 320 misfires vs the others which have 1-3. No clue if not having a crank variation relearn would cause a huge misfire on one cylinder? and when I attempted it couldn't find brake pedal was being pressed.

I guess I'm just mad as I've been chasing a slight misfire for 7 years now that seems like is hit or miss on severity of it. To top it off really wanted to do the Michigan mile and with the car running like this that's out of the question as it's next month then friend was trying to setup a race with 06 mustang with 420 at the wheels (butt dyno don't count, nor guesses)

took me 1/2 day to figure out cobalts misfire as it was a coil pack, borrowed one from wifes HHR and found out Friend and I are going to look things over tomorrow. I'm to the point of pulling my hair out.

I tried one of my friends plug wires and car ran worse then before, but I didn't use an grease on the plug ends and one didn't fit as snug as I'd like, but the rain has set in so working on it right now can't do.

ZZP is booked as I was going to give up my 40k mile m90 with their DUB system and pulley to have them diagnose it.

feels like finding a needle in a haystack *end rant*

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3800 SC/IC Formula whines more than your girl... 12.7@113 330 HP/430TQ
08 Cobalt SS TC - ZZP tuned, K&N SRI, 6k HID's 13.31@107

[This message has been edited by LoW_KeY (edited 06-04-2014).]

You are lucky in that the scanner is picking up and showing cylinder #5.

That means you can swap the positions between the injectors, coils, plugs and plug wires (swap each with a different cylinder) and see if the misfire moves to another cylinder. If it moves, then you will know what part the misfire followed. It it didn't move, then its time to start checking the wiring for cylinder #5 and the compression.

What are the criteria for a misfire? No spark? No fuel? Weak spark? How does the ECM know it happened?

IMPORTANT WARNING TO ALL GUYS NAMED CLIFF: BE WARY OF ALL BLUE FIEROS!

if its showing number five you can swap plugs, wires, and coil packs and see if it moves. Could be a bleeding injector also. does it do it all the time or just under load?

it did it mostly under a load a hard load and randomly, I'd say 98% of the time... I decided to try for kick seafoam in the gas tank... drove it to work with it in, came out 8 hours later. I was curious if it was going to do it again. I didn't experience it. Not sure if in that 8 hour time frame it possibly broke stuff up to clean injector whilte it sat?

I ran it hard from 2nd and 3rd no misfire, and this was driving around my city then going out in country with multiple stops.

I know my friend pulled plug wire from coil pack and we started it said it had strong spark, can't go upon looks to determine if it's strong. I did change plug out and did another plug wire, ran like crap with wire, but I didn't have any grease for plug wire, doh!

Like I stated it's gone now? so I'll go for another test drive today and see. I plan on to swap coils around see if it follows.

[This message has been edited by LoW_KeY (edited 06-05-2014).]

The dielectric grease is non-conductive!. It should not be put on the tips of the plugs between the contact points! It's main purpose is to seal out moisture from entering between the plug boot and the insulator of the spark plug. Be sure to clean that crap off of your metal-to-metal contact points or you will have weak spark.

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ARCHIES JUNK IS FASTER THAN SHAUNNA'S JUNK
12.3 is faster than a 13.2

thought it was made for the boots and to be put on the plugs?

I did too many moons ago then i did some research and found its didnt conduct electricity at all lol. Soi cleaned it off my plugs and out of the metal clips inside the boots and my misfires went away. It sounds like your seafoam worked but it doesnt hurt to remove all culprits.

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ARCHIES JUNK IS FASTER THAN SHAUNNA'S JUNK
12.3 is faster than a 13.2

I chased a random misfire (but mostly #5) for quite a while. Mine turned out to be a leaky SC gasket. Check the torque on the SC bolts- on mine the 3 near the intake would loosen.

quote Originally posted by LoW_KeY: "... just wanna roll it over a cliff." "... spent a bunch of money on it already..."

Been there too - with the Indy...

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Calgary time/temp

3.4L Supercharged 87 GT Click me
Super Duty 4 Indy #163 Click me

hrm *puts a sign up infront of his place labeled "over a cliff" *

I hate to say this, but...... I had the exact same problem that you're experiencing with my L67 Fiero and I chased it for over a year before figuring out that the #3 cylinder had a chipped exhaust valve and seat. The valves float and spin so when the two chips lined up it created the misfire (low compression misfire) and it was intermittent. I really hope that's not your problem too.

Over the weekend I removed cleaned and regapped my plugs down to .040. I havent noticed any misfires and it runs stronger. But like you I also put some dielectric on the spark plug end where the wire connects. I am running the 10.5 ZZP wires.

I was grilling this evening invited friend over to drive car after I did... he went out and gave it hell as I told him to to a certain extent. He came back with a grin on his face said "no misfires and said he upset a few people" the car did sit for awhile before new trans and getting alternator bracket fixed.

So far it's clear, but I do need to do the crank variation relearn to make sure it's 100% up to par day 2 no misfire