turbo problem or not

[mitsufrkr]

had an replacment turbo put on car sounds good. but now between 4500 to 5000 rpm runs rough and after driving the car for an little while till motor is warm. rough idle reves from 1000rpm gose down to 500rpm.and dose that constaly.

 

[Isotta91]

what do u mean by rough? fuel cut, or just a shaky feeling from the motor? for the idle, u may just have an idle surge. check www.vfaq.com for that, they have 2 ways u can fix it, but the easiest way is just try and adjust ur biss, see what that does. it's prolly a more complex situation with that tho.

 

[mitsufrkr]

an shaky feeling in the motor like something is lose,but it only dose that between 4500 and 5000rpm and will not go any higherin the rpms . on that outher thing AKA idle surge. what is biss and how do i adjust it. im sorry if im complcated but im new at this,my first turbo car and surly not my last, and what is the outher way of fixing the idle surge. i dont know if this matters but the check engine light stays on utill i hit the gas. thanks anyway.

 

[twenty5psi]

Originally posted by mitsufrkr
an shaky feeling in the motor like something is lose,but it only dose that between 4500 and 5000rpm and will not go any higherin the rpms . on that outher thing AKA idle surge. what is biss and how do i adjust it. im sorry if im complcated but im new at this,my first turbo car and surly not my last, and what is the outher way of fixing the idle surge. i dont know if this matters but the check engine light stays on utill i hit the gas. thanks anyway.

have someone pull the code..its probaly something with your fuel if it goes off after you hit the gas..maybe your timing is really off but i dont think thatd throw a cel..def have that code pulled though and go from there..oh and it does sound like fuel cut..you can adjust the biss screw ontop of the throttle body..

 

[Isotta91]

heres where the biss screw is. turn it counterclockwise to lower the idle level, clockwise to raise it.

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[mitsufrkr]

do you think i should raise it or lower it and how would i see an differance. by the way thanks a lot need more people like you on this site.