boost cuts out

[quiksilvia]

ok, so i put on my joe p. mbc and for about a week, everything was fine and dandy. then it started gayifying, if i floored it, as soon as it reached my set boost, it would cut in and out real quik until i let off the gas. if i held the pedal at 90% throttle, nothing of the sort would happen, it would boost as normal. so i thought the mbc was the problem, but the boost cut still happens, not as often but it does happen, so its not the mbc. any ideas? thx

[msaskin]

Fuel cut? (do SR's hit fuel cut? I know DSM's do, as do most other turbocharged cars I've driven)

Lower your boost a bit and try it again.

~matt

[Hijacker]

lower the boost, like matt said. and if it continues check for blowby. My turbo was doing something similar, so I pulled the hotpipe, and it was coated in oil. Blown turbo.

[quiksilvia]

i took the mbc off after lowering the boost, and the lower the boost, the less frequently i have the problem. ill check that hot pipe thing though, unfortunate as it may be. i think its gonna be coated in oil and i dont think its a fuel cut

[quiksilvia]

the main concentration of oil was in the tube right before the tb, and it seems to be seeping out of the connection of that tube to the plastic piece that runs across the radiator, bad or good?

[Hijacker]

oil concentration in the pipes is never good. the next thing to do is pull the compressor inlet elbow off and check for shaftplay.

[quiksilvia]

it was fine when i replaced the head in october as far as shaft play, but ill look at that too, shaft play = oil is getting past shaft and into turbo correct?

[Hijacker]

yep. when you start to get shaft play, that's usually the thrust washer and bearing starting to give out. there's an outer retaining plate that the thrust bearing sticks out of. When he starts wobbling, oil can leak out throught the retainer plate.