Hey forum members. I have an 06 Evo with 54k miles. The car has full bolt ons / 272 cams / fp red, dual map tune, etc. The car runs flawless. Not one single issue with it EXCEPT, for when I launch the car (mainly only been noticed at the dragstrip) and after shift(s), it bogs terribly. Car completely just cuts out for maybe a half second, then kicks back in all the way through, until the next gear, will do the same exact thing (sometimes).

I noticed if i shift super super early then it will not happen.

I finally found time to make it to my tuner and let him experience it. He says he hasn't ever seen anything like it. He logged my launch and the log doesn't show anything abnormal. (I am in the process of getting him to send me the log so ya'll can see it)

He said it sounds like 1 or 2 of the cylinders just completely shut out for a split second right after each shift. I have a spoolin up cop kit on the car. We tried swapping the sparktech cop kit off his personal 9 second evo on to see if it still happened and it did.

Him and I are both really clueless as to what could be going on. He thinks it could be a wiring issue somewhere in the coil pack harness or something.

During that split second it hesitates, he said the afr goes just a little rich which tells him its not a fuel issue?

Some more key notes:
-I've tried downsizing spark gap from .024 to .020 and still happens
-Happens on both pump and e85
-It's almost like spark blowout type of feeling

Please help before I lose hope... it's making my low 11 sec car, a high 12 sec car

I'm sure i am missing a good amount of info needed.. just lmk what information you need to help me figure this issue out.

 

Stock ECU?
Is NLTS activated?
Do you only experience it on the 1-2 upshift/WOT/High rpm?
Does it do it on any other gear shift?

I haven't looked at stock ECU map in years but if NLTS is activated, there may be a timer in which the ECU will cut spark and enrich to maintain the RPM.... ask your tuner what this timer is set to? and try reducing it to note the impact.

 

stock ecu, yes.
nlts is turned OFF.
and it always happens on 1-2 shift it seems. however it has one time done it in every single gear going down the track. 1-2, 2-3, 3-4.. happens when winding out the gear (shifting a little before 8k). and i can never get it to happen if i get on it from a roll in 1st or 2nd. seems like it only wants to happen when i launch the car off the factory launch control (set at 5400rpm)

we actually tried to turn nlts on and it still happened

 

Did you guys try deactivating the launch controller and try it?

 

No we did not.

 

If it's an ignition misfire, the log will show up as lean.
If it's showing rich, then maybe it's rich?

What about the cam sensor?
How close is it to the ex maniflod and is there a heat shield?

Have you taken a look at the spark plugs?
Photos?

 

Original Cam sensor broke last year, replaced it with an autozone sensor and has been. Problem occurred with the old oem sensor and with the new autozone sensor. My fp race manifold has a heat shield but there is no heat shield on the sensor itself.

I will get you some plug picures shortly. They have less than 1500 miles on them and we're swapped in January.

 

You seem to have started about 10 different threads on basicly the same thing...............it's not running right.
One of them ended saying that it was now OK?

Do you think you've got 10 different problems or do you think it's just one or two?

 

the threads would end up getting pushed into one thought or would die off. Or I would get new information so I decided to create a new one. The coolant leak was a simple fix. Was just the hose going to the turbo had a little split in it.

the car literally runs perfect aside from the issue stated in my op

 

Any chance there is something rattling which the knock sensor is picking up pulling timing bc of that? Im thinking during a launch the car might be hopping around as well as banging the 1-2 it might be making some sort of noise. Granted, if its knocking then your tuner should see that in the logs so I'd image he would have said something.

 

Try replacing your MAP sensor with a known good one.

 

Any chance of boost cut? Boost leak?
Pretty sure boost cut shows in the logs.

 

Knock on the logs showed 0 throughout the entire pull except for 3 places (in the spreadsheet) had 1 knock count each (which I was told is nothing to worry about)

I just replaced the oem map sensor with a Omni power 4 bar. Problem has happened on both.

Tuner says def not boost cut. And he just recently fixed a few leaks I had and says it's not a boost leak.

 

When it bogs down is it usually when you shift under WOT, then back to WOT? Curious as I've had that same problem appear a couple times.

Do you run a test pipe or do you have a cat installed? What PSI you running? I may have missed it.

 

in for results, I was going to say it sounds like NLTS but you said its disabled