Building boost but not going faster

[00RS03MSP]

Hey all I'm currently in a situation right now where my 2003 msp builds boost up at 30-40% throttle and then it just cuts out hard like a fuel cut. I have just replaced my radiator and I believe there is still a small amount of air in the system. I don't have any cats and I have a non-fouler for the downstream O2 sensor. However, a lot of times if I go 100% throttle it hesitates a little then it gets its power back. Sometimes it will build up boost and then cut out hard. All the intercooler piping and air intake piping is clamped tight. I'm also not throwing any CEL codes. Any help is much appreciated!

Thanks!
00RS03MSP

 

[xExoticC]

I had a similar issue when I purchased my msp, I just gapped the spark plugs to the right specifications and that fixed my problem.

 

[TURBOJ1]

Sounds like it could be an ignition issue....I had this on mine but it only happened like +25lbs of boost

 

[Blake D]

Check the wastegate actuator also.

 

[00RS03MSP]

I'm getting the wastegate change at this moment. I went with the turbosmart IWG 75. The instructions tell me to preset it at 2mm but there is too much resistance to actually pull it out that much. Should I just put it on bolt it on and go from there?

 

[00RS03MSP]

All right the wastegate fixed the problem and now its staying a nice and steady 7 psi! It is still slightly lagging a little so I'm going to change the spark plugs next.

 

[00RS03MSP]

What did you do ignition wise to fix the issue?

 

[00RS03MSP]

Ok I'll have to do that then, the spark plugs I got were .44 for the gap. I read on the forum that the gap is supposed to be any from .28-.32.

 

[Blake D]

if you just walk into a parts store they will give you the wrong plugs. stock replacement plugs are NGK PZFR6F. make sure there gaped between .28 and .32

 

[00RS03MSP]

Ok thanks. I just gapped the wrong plugs to the right specification. I believe I gapped them to like .029-.030.

 

[TURBOJ1]

What did you do ignition wise to fix the issue?

I never got a chance to figure it out/fix it......why? Because broke transmission (notcool)

 

[00RS03MSP]

Oh dang, that sucks! Did you get a new transmission?

 

[00RS03MSP]

All I gapped my spark plugs correctly but its still doing it. Any suggestions on what else it could be?

 

[Schwamm]

All I gapped my spark plugs correctly but its still doing it. Any suggestions on what else it could be?

Have you checked the wires and coil packs as well? I've had ignition issues under load caused by both before.

 

[IllaNoizeTV]

I had the same issue. One of the wires connecting to the coilpack had a bad connection. Had to super glue it making good contact to the coilpack