partial throttle lag/hesitation popping sputtering???

[10lbsmocc]

I am just curious about something that is a reoccuring problem on my MSP. No matter what I have done I still have this funky hesitation. It usually happens in 5th gear at partial to no boost where it feels like the car wants to accelerate but it goes slower and then it starts sputtering and I have to let off the gas completly somrtimes this clears the problem or I have to go wide open throttle or downshift to get it to stop. I just changed the plugs but no help there.

Here is my list of mods...
Injen SRI
Pannauto FMIC
turboxs MBC (10lbs)
turboxs bypass valve recirc in stock location
GHL turbo back exhaust
split second AFC

any help would be appreciated because I am getting tired of this problem..

Matt

 

[daedalus]

boost leak?

 

[10lbsmocc]

no it holds steady because i thought the same but i checked my clamps

 

[MSP #167]

i know exactly what your talking about, its hard to explain, almost feels like there is air trapped somewhere.

I'm not sure exactly what it is though, i just don't really give it gas in 5th anymore.

 

[10lbsmocc]

well sometimes it does it in 4th too I was following my friends WRX back to my house so i could hear his new invidia turboback and I was in 4th and it started to do it. oh and my car is faster than his by the way haha

 

[CustomMSP]

You might want to check all your vac lines.

 

[10lbsmocc]

custom,
that is something i will check 2morrow but it isn't consistent enough to be a vac leak (I think but i could be wrong)

 

[spacemonkey]

leak...I would cheakc your vacumn lines and make sure your sensors are in/in the right location.

 

[CustomMSP]

Did you have the problem before all your mods?

 

[10lbsmocc]

custom,
I honestly can't remember when it started but it has been pretty much the whole time I have owned my car

 

[CustomMSP]

Check your PCV valve make sure it's in all the way. Also, have you had the injen since you had the car? If you got the time, throw on your stock airbox and see how it goes. I'm not sure if that's possible with the Pannauto FMIC. I would also check the compression.

 

[BlkZoomZoom]

Sounds like the vehicle is expecting more air than its seeing, thus dumping fuel for the air thats not there, causing a rich condition.

 

[spacemonkey]

Sounds like the vehicle is expecting more air than its seeing, thus dumping fuel for the air thats not there, causing a rich condition.

like an Atmo BOV...but im venting and it dips down to 10:1 A/F but it never bogs down that bad.

 

[10lbsmocc]

I will check the pcv and no I haven't had the injen on all the time and it is converted to a short ram and i am still recirculating. I think my best guess is the vac lines so i will try that and replace all of them with nice new silicone lines and go from there. But if anybody has anymore suggestions please let me know

Thanks again

 

[Rawyzf]

Do you still have the stock BPV?

 

[FSDET]

i think its a common MSP problem. i get that in my car too thats why i either go WOT or not boost at all.

 

[CustomMSP]

I don't know if that's too common though. I have a very smooth/strong 5th gear.

Have you changed your plugs 10lbs?

 

[10lbsmocc]

yep did a new battery and fresh plugs already and today my mechanic went over all the vac lines no cracks.

 

[jonbig]

mine does that in every gear pretty much all the time

 

[Tommy1005]

mine does it in every gear, well atleast 2nd through 5th.......I didn't have the problem until I put the Greddy Type-S vented to atmosphere on, so I'm thinking the screw may be too tight, I need to spend some more time tweaking it, but then I have to re-tweak my boost controller too to get them all working together.