[RESOLVED] Stutter problem around 4-4500k rpm

[Pirrofab]

Did you try a boost leak test? I was having vry similar probelms and it turned out my b.o.v was leaking at the flange of the b.o.v itself. I built a boost leak tester for about 6 dollars from a local hardware store. it wouldn't hurt to test it. If incoming air is being measured from your air flow sensor and being lost through a boost leak the motor won't have the corect a/f ratio which could cause misfires therefore giving you a stuttering problem

 

[95eclipseSlow]

well actually i havent done a boost leak test yet. Once again,i highly doubt this is the problem, but i will do a boost leak test tomorrow to rule it out.

 

[thatblondechik]

Just F.Y.I. (since I've been having the same problem), I've done countless leakdown tests on my car to no avail. Holds pressure very nicely.

I'm pretty sure that "stutter" lies somewhere in air/fuel management since I had no problems until I added an AFC. I'm not saying don't do your leak test, it could very well be your problem...I'm just saying that it didn't resolve anything for me.

 

[95eclipseSlow]

i was thinking the same thing. it has to be something with the air/fuel i know it!

 

[thatblondechik]

Well do your leak down and see what that tells you...boost leaks can cause similar symptoms so don't rule it out until you're sure!

 

[Turbo Talon DL]

I am having the same exact problem today and as soon as it did it yesterday I knew what it was related to. You could have an exhaust leak or something that you missed. I have one but its not throwing off my readings much but since I started having this happen my fuel trim Medium and High went from high 90%s to low 103-105%. My O2s went extra rich too when it studdered.

 

[63tuner]

1) Change/check the MAF sensor
2) Change/check the ECU
3) Change/check the fuel pump and fuel regulator

 

[95eclipseSlow]

I have an external wastegate and Im not using the dump tube. Im not so sure if an exhaust leak would cause this specific problem either, i'll test for leaks both boost and exhaust today and let you know. Its weird because its completely fine until WOT.

 

[Maranello993]

http://www.dsmtuners.com/forums/pro...ear-i-floor-redline-flickers-3500-4000-a.html

People were saying this guy had a boost leak but he just ended up changing the plugs JUST LIKE ME and it fixed the problem. Like I said I had this problem with the same WOT stutter. Don't rule out boost leak but try the simple fix first.

 

[Turbo Talon DL]

I am having the same exact problem today and as soon as it did it yesterday I knew what it was related to. You could have an exhaust leak or something that you missed. I have one but its not throwing off my readings much but since I started having this happen my fuel trim Medium and High went from high 90%s to low 103-105%. My O2s went extra rich too when it studdered.

Fixed the problem. Just the UICP popped off the TB elbow coupler.