Boost control problem

[Jeff822]

Ok, so ever since i sold my friend my old fmic and put back on the stock smic and piping my boost has been spiking crazy high, i since then got a new fmic and upper piping and when i got it there was a hole in the weld on the lower IC pipe, put some JB weld on that and still have to do another boost leak test. But here's my problem, boost is still shooting past 20 psi and i have no clue why, i backed my MBC off from 18 to 9 psi it held at 9 without a probelm at 1/2-3/4 throttle, so i bumped it up another turn to 11 psi, still holds at 11 psi at 1/2-3/4 throttle. Why is it holding at 11 psi but wouldnt hold at 18 psi? When it was set at 18 it would go to 5 psi like normal and then just shoot up like nothing. Now with it set at 11 psi it does the same goes to 5 like normal and shoots up but holds at 11/12 psi, i have yet to check for any pin holes or anything in the boost controller lines but none of them are kinked. Im hoping its not the WGA and just something simple and stupid, btw there is NO power what-so ever from the boost, i can hear the turbo spool and the see the boost gauge rise but i feel no power. Could there be a leak somewhere else? If anyone has any questions or anything or any info please share. Thanks, Jeff

 

[FORMONTOYA]

My vote is for a boost leak.

When I put mine together it would spike 2-3PSI over my set point also. It turned out to be a boost leak. I have my gauge coming off the FPS line and the MBC running off the turbine housing. Fixed a boost leak in the throttle body and problem solved.

It "feels" a lot better now at 16PSI than it did when it was spiking at 18-19PSI.

I plan on 20PSI in the winter and during next summer after a WI kit, so I test to 25PSI.

 

[danyz250f]

Do a leak test, but also my friend had a similar problem and it turned out to be his spark plugs, he had cheap autolite ones and after the ngk bpr6es gapped to .028 his problem fixed.

I think a leak test is in order. You are probably running super rich with the leak. So maybe when you get it fixed check the plugs too, and see if they are fouled.