Misfire on #2

cobbtunedsti

New member
This has been on going for about a month.. It's only happens at idle or cold starts!!! I just had Calvin look at the tune yesterday and it's 100%.. He even turned the threshold up so it wouldn't misfire because of my engine mounts.. Where would you begin?? Coil Packs!
 

HolyCrapItsFast

Drinks beer!
Refresh my memory... do you have larger than stock injectors and/or a light weight flywheel or pulley?
 

cobbtunedsti

New member
All the above:) Act street lite flywheel, cobb crank pully, DW 1000cc injectors
 

HolyCrapItsFast

Drinks beer!
I fear you have to live with it. Each one of these components will, in on them selves, cause misfire codes but all three together you are almost guarantied misfire codes

If your engine is running smooth and you can't feel any actual misfires you may need to ask Calvin to loosen of those thresholds some more.

If you are running gasoline the injector pulse widths are very short and this can cause misfires at idle. If you switch to E85 this will improve that situation because the pulse width is greater. The other thing you can do is simply increase your idle. You can do this your self with the AP.
 

cobbtunedsti

New member
Calvin did rise it even more.. I rised my idle to about 900rpm's when this first happened.. The car has always ran on E85 since the build!! I wouldn't mine to live with it but engine light comes on every 3rd day.. On the dot!!! I then have to reset it and the throttle response isn't great after you reset it (Pain)!!
 

cobbtunedsti

New member
Which part of the engine do you need and I'll see if I have it in my photo shop.. What seems off?
 

cobbtunedsti

New member
It's dark outside but this is what I got!!

1301676750.jpg

1301676626.jpg
[/IMG]http://i1102.photobucket.com/albums/g449/cobbtunedsti/1301676626.jpg
 

cobbtunedsti

New member
Ohh i don't have one.. Stock!! Me and Calvin went over the tune for 2 hrs yesterday!! It's 100%!!
 

IGOTASTi

System Operator
Staff member
Look at my journal Carl. I have the sun automobile company grounding kit. I love it, and it did help for sure.
 

IGOTASTi

System Operator
Staff member
Mine looks good and its red in color, lol.
 

cobbtunedsti

New member
Calvin said

I would swap the plug from #2 to #4 and see if the miss fire moves with the plug. If not then move the coil if it still missfires on Cyl #2 after moving both then you can rule them out.
 

toomes

New member
I would like to jump into the middle of this thread because there has been a lot of discussion around all the same issues and symptoms I have had.

Grounding kit?
Was a great try on my behalf, didn't really make a difference in the end.

Cams?
272 Kelfords on my engine, 272 on yours, which means we are going to burble and misfire based on the stock ecu. Mostly cyl 2 and 4, ESPECIALLY cyl 2 (I changed plugs and coils, no difference.)

Stock ECU?
Yes, looks like we are both running it and that's part of our problem. I had heard a ton of times now that AEM or HYDRA will get rid of this, why - I don't have an answer specifically.

Specific cylinder fueling?
We are starting to experiment on changing the fueling for each cylinder individually.

When?
Again, yours only happens at idle, as does mine. Sometimes up to 15% of the time :lol: at cruise its buttery smooth and boost. No roughness detected.




In all honesty, I wouldn't worry about it :lol:
 

cobbtunedsti

New member
Ok so do leave the engine light on and hammer down???? I haven't had time to do what Calvin said yet!!!! The if it's not a coil,plug, or injector then what?? Calvin said diffently NOT a piston!!!
 

cobbtunedsti

New member
New pic!!! Must see!!!!!

1304641784.jpg

Pretty sure this is my problem... LMAO!!!!!
The guy that done my compression test must have broke it!! I pulled it out and it just fell apart!!!!
 
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