fmic boost @ 15psi = problems is it fuel cut?

[asd_gst]

this is my set up, walbro 190, stock ecu, stock injectors, 14b with ported evo3 turbine housing, 2 1/2" o2 housing with wastegate dump, and punishment fmic with 2 1/2" piping.
here is my problem, when i turn my car on and drive when i boost say 12psi everything is fine then when i hit 15 psi the car will jerk and my logger says air volume 7 then drops to 5 when the car jerks, knock is 0, fuel is trims are good. but the car will only do this like for the first 5 minutes im driving, it feels like i blow off a intercooler pipe but after driving for around 5-10 minutes i can boost up to 18psi fine no knock no jerks no air volume drops. but it seriously feels like i blow off the pipe but then car runs fine and pulls hard after a few minutes of driving and i have no clue what it is. could this be fuel cut? if so why does it only do it when i first start driving?

 

[grantman10]

I am having this SAME EXACT PROBLEM! I just installed my SSAC FMIC and have the boost set to about 14-15psi, and if the car hasent been running for a long time this will happen.

Everytime i have been WOT, and everytime it sounds EXACTLY like i blew off one of my intercooler pipes. I just want to know for sure if this is fuel cut, because if not i have some serious problems. Another thing that leads me to believe that this is fuel cut is my logs. All the logs i have done on my car have had o2 voltage readings of 1.00 at WOT in the higher RPMS (above 4k).

I think i have some major boost leaks going on. To the opposition, i thought fuel cut was like a brick wall?

 

[bluetlr2001]

Have you done a boost leak test yet?

 

[airmail96]

Is the car warmed up all the way or is it still cold? I know my car doesn't like to be pushed hard unless I let it properly warm up. Apparently it runs really lean till full warmed up.

 

[grantman10]

I have to do a boost leak test still. Believe me, its the next thing on my list. But does fuel cut sound like an intercooler pipe poping off to anyone else?

 

[bluetlr2001]

Fuel cut normally feels like you just hit a brick wall. The car will shut off the fuel for a quick second. Are you saying that your car feels like it just looses boost or is it cutting out?

 

[grantman10]

There is no brick wall. The car just feels exactly like i blew an intercooler pipe off. As instinct, i usually push the clutch pedal in withing milliseconds. I always expect the car to stall, like it would if a charge pipe were to blow off, however, it is always fine. There is obviously a change in momentum; I go from accelerating rapidly, to not, but i dont feel any "brick wall".

 

[GSX93DSM]

I would also say a boost leak. I would also hold out turning it up to 18psi until you get bigger injectors. Just so your duty cycle is low and the injectors are not closed to being maxed out.

 

[asd_gst]

my cars boost stays at 15-18 whatever its set at and yes it feels like i hit a brick wall. but it will do this after driving for awhile and car is warmed up

 

[DSMopar]

It's normal and pretty simple....

A. It is fuel cut likely

B. It happens when cold because the entire intake tract is cooler, compressor housing, intercooler, piping, TB, intake... furthermore the underhood temps are cooler meaning cooler air being drawn in. So basically you're flowing more air at a lower PSI because of the temp difference. Same thing happens to my shit when cold with a supra side mount.

 

[toofast82]

I wouldnt be beating on your car when its not fully warmed up. I would do a boost leak test as mentioned but it could be fuel cut as well or cold car stumble