engine problems

[mad_matty]

hey guys hope this is the rite place to post my problem hopefully someone will be able to help me out.

i have worken on engines br4 so im slowly gaining abit of knowledge but this is the first time workin on a nissan and also a turbo so i thought i would come to teh pro's

basicly im not sure what the problem is. im told it may be a boostin problem but im not sure so maybe someone will be able to help..

here goes!!...


rite im sittin in the car. idle is fine. i put it in first start to drive get to about 1.5k revs and it feels like its missfirein. as the revs go higher.
as the revs go higher my turbo gauge starts decreasin to - side, -1,-2,-3,-4 and so on till it gets to -7. then i get to about 3, 3.5k then all the sudden the turbo gauge switches to + and the heavens open up and the thing feels like its guuna take off so basicly it feels fine after about 3 3.5k.
it does the same weather the car is movin or stand still.

anyone no what it maybe?

i brought it from a bloke a no and he is a really gunuine bloke and he wouldn't lie and be4 he sold me he had this done to it.

Has done 70,000miles, gearbox has been reconned (also filed with £100 worth of race-spec box oil), crank replaced, all turbo gaskets, and belts, and serviced.

oo it also has fitted to it

Forge Motorsport Dump Valve
JR EVO VI Air Filter w/adaptor plate
17" konig speed six alloys ( but i will probally be puttin on some 15's or 16's as i think the 17's are to big)
MONGOOSE FULL DE CAT Exhaust system with 5" slash cut box

just incase it may affect anything

thanks for the help in advance guys

 

[Fast Guy]

It might be worth checking to see if any vacuum hoses are split.
Any idea when it was last serviced? plugs/leads etc?

Have you tried doing a fault code check, there should be a sticky at the top of this section.

 

[mad_matty]

thanks mate i will try that at the weekend. it was meant to be serviced a month or two befor i brought the car. the leads look pretty new but i have not had the chance to look at the plugs yet.

havent tried a fault code check yet. so i will look at the sticky cheers mate.

anything else worth checking while im workin on the car?