R33 Engine Problem

[unarmed_skyline]

Ok, my mates series 1.5 r33 gts-t is playing up need some ideas on what to test,

this is the go, car defonatly has a manifold leak fixing that tommorow makes the car sound horrible,

now he has just bought this car privetly and got it cheap and i can see why, (should have cheacked it more before he bought it)

now the bov is a vent to air type says hks on it but its clearly made out of plastic, also has a dual stage turbosmart bleeder valve,

the stock boost gauge was saying it was boosting up to 5 psi and the aktermarket one said anywhere from 2-12 psi (very dodgy gauge it sticks sometimes and you can tap it and it will read boost) now the car didnt feel like it was boosting at all, the bov didnt sound as if it was letting of much pressure either, so i assume the car wasnt boosting correctly, the car was also backfiring above 4000 rpm and half to wide open throttle, it felt as if the car was pulling the power out a bit to but not quite like rich and retart,

so had a fiddle and we took off the bleeder valve and put on the stock boost controller, and guess what the car pulled way harder and felt like it was boosting

but then bang bov popped off yay now we defonly had boost lol the crappy bov flew off dew to poor design, so took the car back and we couldnt get the bov back on cause its stuffed, didnt have a stock one handy either soo i hooked up a straight pipe and bypassed the bov so that there is no bov running at all just to test the car,

Note exhaust manifold gasket is leaking, now we took the car for a drive and now with half to wide open throttle after 4000 rmp the car starts back firing like anything and looses all power as if there is either a massive air leak or theres not enough fuel, now i tryed driving the car with 1/4 throttle and slight boost and the car revs right threw the rev range with no problems at all and quite smooth and freely

Its only at half to wide open throttle it seems to be cutting out, anyone got any ideas, ive cheacked all the connections to all hoses and connectors and everything seems fine the car has stock ecu is running stock boost, taking the manifold off tommorow to replace the gasket,, so im going to check the turbo tommorow and rig up a spare bov i had lying around but i doubt this will fix the underlying problem

can you guys throw some ideas at me, thinking mabye fuel reg is stuffed, or ecu running into rich and retard for some reason mabye afm but it runs fine without wot, changed the fuel filter that didnt help, mabye the cat is blocked but it didnt seem to be getting red hot after driving so doubt that, changed over

the coil packs and sparkies, running out of idea thou

[paulr33]

fix the leak, replace the bov with a factory one and the car will drive like new

[Devils_Advocate21]

As paul said fix the manifold leak and replace bov and "should" be ok after that, then let us know what and how it goes