need help... car is sputtering above 7psi

[jsigone]

Ok, my bud just got his car on Monday. He got it shipped from maryland here to cali. Has a built motor wit about 1500 miles on it. Motor has Eagle rods, Weisco 9.0 compression pistons, mitsu metal HG, ARP main bolt and head studs. The car has a 14b on there with blue top JDM 450cc injectors, 3" turbo back exhuast, FMIC and 2" LIC and 2.25" UIC and Blaha MAS.

problems: He came to me telling me there is a boost leak. I took it for a test spin boosted 6psi then sputters and more gas = more sputtering and shaking, the BOV was faint, pulled over and found a broke vac line off the BOV. Checked his AFC setting and it was at 2 cyl instead of 4cyl. I don't know what kind of damaged that may have caused. I asked him if he played with the AFC hen he got it and he said he pressed a few button etc, but not know what to do or how to oppperate the AFC. Ok, so I set everything to correct on the AFC. Take it for another test drive and it boost bout 10psi then bam, sputters again. I'm not hitting FC I know that. It doesn't feel nor sound like a boost leak. I'm running out of ideas on what it can be. Anyone, please help. Also there is a weird vibration that goes from the engine bay to the of the car running on the passenger side. it happens when I let off the gas.

 

[teg21]

Could be a ton of things I would suggest a compression test and depending on that possibly a leak down test. I would also check the turbo for shaft play. You said you could hear the blow off valve I would check to see if that works. How is he monitoring boost I would suggest turning down the boost to about 9 and taking it out and see if it has any problems then at least you have narrowed it down to a problem with the turbo. Also do all the 4 cyclinders work now? Hope this helps at least some

 

[jsigone]

I haven't done a comp test yet. I told the guy that it should get done to see how hte motor is, even though it was just built. The turbo is fine, good fins, no shaft play. He has a boost and AF gauge. No EGTs no logger. I don't hear any rod knock nor a bent valve. Idles fine, but a little high. about 1200rpm, but when you start it u, it revs to 3k then comes down after a minute or so. I'm gonna replace some of the hose tomorrow and plugs.