Misfire @ 4K RPM w/ video

[Spaniard]

If I have the car in gear and I just floor it, the car misfires exactly at 4K. If I do 60,70 or 80% throttle for instance it will not misfire when passing 4k. It tends to do it when it's getting colder, cause during the mid-day heat of florida it just hauls. Im confused. It is always 4k rpms, nothing else. So the problem is rpm direct. I have made videos cause its hard to explain with words.

You see below.

1st video.

http://www.youtube.com/watch?v=16hfC6R7Aqc

This video it doesnt do it in 2nd gear cause i dont floor it, but it does it afterwards in 3rd gear.

http://www.youtube.com/watch?v=bJlpQxVOdj0

Let me know what you guys think. I have a few ideas of my own, but I want to hear what you guys think first.

 

[cnewingham]

hmmmm

 

[Spaniard]

http://www.youtube.com/watch?v=mfMLFwmQDO4

Here is another one for you to see.

 

[doom26464]

im going to say spark plugs

 

[Spaniard]

im going to say spark plugs

Cant be. Spark plugs dont pick when to fail exactly. The misfire is happening at a specific rpm at WOT only.

 

[werewolves182]

1JZ right? At what rpm do you hit full boost at 100% throttle? Ive experienced that same type of misfire and gapping my plugs to .027 fixed it.

 

[The Reaper]

either that or maybe check your Coil packs for stem cracks???

mine broke up under boost from 4K to rev limiter and it was the cracks in the stems

 

[Spaniard]

1JZ right? At what rpm do you hit full boost at 100% throttle? Ive experienced that same type of misfire and gapping my plugs to .027 fixed it.

plugs are gapped at .25 and are new

either that or maybe check your Coil packs for stem cracks???

mine broke up under boost from 4K to rev limiter and it was the cracks in the stems

i doubt this, but have confirmed and will re-confirm today.

 

[rakkasan]

I just developed the same symtoms. New plugs, gapped at .27. My coils are sleeved, so I don't think cracks are the issue, but I'll check them. I think that my coil harness is the problem, I noticed that one of the wires going into the coil has exposed wire due to changing the plugs so much. I'll tape it up and see what happens....

 

[The Reaper]

i doubt its the exposed wire but anything is possible.

i remember someone posted that busted coil pack connectors can cause a car to really mess up, but i have NO plastic connectors at all. they ALL broke when installing the harness.

like its literally just the two wires plugging seperately into the coil pack. no plastic at all

no problems with missing or running rough whatsoever. still going to buy new connectors but just felt like throwing this out there.

 

[drewgo]

Do you have 1 or 2 fuel pumps...

 

[rakkasan]

i doubt its the exposed wire but anything is possible.

i remember someone posted that busted coil pack connectors can cause a car to really mess up, but i have NO plastic connectors at all. they ALL broke when installing the harness.

like its literally just the two wires plugging seperately into the coil pack. no plastic at all

no problems with missing or running rough whatsoever. still going to buy new connectors but just felt like throwing this out there.

I have three 'busted' connectors. The connector itself is intact, but they're missing the little tab that locks them into the coil. I don't see how that could pose a problem....

 

[rakkasan]

Do you have 1 or 2 fuel pumps...

For me, one

 

[Spaniard]

One here. Going to try a different ecu today hopefully.

 

[Spaniard]

either that or maybe check your Coil packs for stem cracks???

mine broke up under boost from 4K to rev limiter and it was the cracks in the stems

Cant be. Spark plugs dont pick when to fail exactly. The misfire is happening at a specific rpm at WOT only.

Like i said before, besides the coil packs no working properly would cause more havoc in other parts of the rpm range. Going to change out the coil packs just in case tomorrow.

 

[The Reaper]

not true.

mine didn't run funny at all until boost from 4K on. stronger signal to the coil packs at the point can cause them to arc where as they won't at low rpm/ low throttle.

 

[Spaniard]

not true.

mine didn't run funny at all until boost from 4K on. stronger signal to the coil packs at the point can cause them to arc where as they won't at low rpm/ low throttle.

okay i see where your coming from, i stand corrected. will keep you guys posted.

 

[Spaniard]

either that or maybe check your Coil packs for stem cracks???

mine broke up under boost from 4K to rev limiter and it was the cracks in the stems

i doubt its the exposed wire but anything is possible.

i remember someone posted that busted coil pack connectors can cause a car to really mess up, but i have NO plastic connectors at all. they ALL broke when installing the harness.

like its literally just the two wires plugging seperately into the coil pack. no plastic at all

no problems with missing or running rough whatsoever. still going to buy new connectors but just felt like throwing this out there.

not true.

mine didn't run funny at all until boost from 4K on. stronger signal to the coil packs at the point can cause them to arc where as they won't at low rpm/ low throttle.

After much debate. I stand corrected. I pulled the coilpacks and they had cracks in the stem and at the top it self. I couldnt believe it. So I was very impatient to get my car running and besides, there was a kid with a mustang gt that was pissing me off about how my car isnt running and his is and much faster v8 bullshit...blah...blah...blah. So I said to him, give me two hours. lol. I went to advance auto. I got some high temp plastic epoxy and put it on the cracks very nicely. Let it dry for about an hour. Put them in, let me car come up to a normal warm-up. Took'em for a ride, and OMG! it pullz! lol. Feels good hearing my turbo spool and push all the way through the rpm range. Oh btw, that kid with the mustang gt beat him by i think it was like a BUS! lol. he was like wtf dude, pretty nice car for a kid that is always working on it. I was like, your dumb.

In any case, thank you all for your kind and generous help.

 

[bluemkiii]

Now post a vid of it running good lol

 

[str8_6]

awesome. should've said thee old "put your money where your mouth is"...