need help car is acting weird

[kouki_monstor]

i tried searching but cant seem to find anything related to my problem.

when i first put the engine together it ran perfectly fine, idling at 700 and everything. i drove it for about a week with no problems, until one day my boost gauge needle all of a sudden got stuck at max boost, then the car started acting funny. at idle it would drop back and forth from 700 to 400 and almost stall, and would be spitting out back smoke out the exhaust.

the weird thing is that a couple days later, i started it up and the boost gauge needle was then stuck at the lowest setting, and would start climbing up slowly as i drove (like a water temp gauge). the car would drive perfectly fine on the way to work, but on the way home the idling thing started again.

i got home, shut the car off, then turned it back on, and it ran fine again. i thought it was a boost or vacuum leak but cant seem to pinpoint the problem, especially when the boost gauge is acting so weird...

sorry for writing a book, but my car's acting weird and i have no other way of describing it. any help would be great. thanks!!

[kouki_monstor]

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