funny occasional boosting problems

[johndoe1003]

ok, i got my 96 rs twin turbo, with frontmount and aftermarket blowoff valve.

SOMETIMES (usually hot) under very light throttle, just about to come on boost, the car splutters and loses power, runs rich (can see black smoke from exhaust) then takes off and is sweet. this only happens as its about to come on boost on the primary turbo. happend the other day, got really bad on the motorway so i pulled over to inspect all my hoses.

seemed ok. so i went to take off, and it ran like absolute ****e, then died at 4 grand, so i grabbed 2nd and floored it, same thing, 4 grand power cut. then got third and it died, so i got off the gas and tried again, then it took off and didnt have another problem the whole trip. yes i will check for codes tomorrow, it didnt have any last time i checked bout a month ago, anyone got any ideas what this problem is?

to me it sounds like an air leak after the turbos or the afm or even some of the symptoms of code 66? just looking for a second or third opinion from people that have a bit more experience with these cars then me haha

[Guest boostcut]

is your blow off valve leaking maybe??? when i got my car the valve seat was loose in the housing and caused it to slip sideways and then it ran like ass. but now that ive glued it in its fine... just a thourght. my bov is a hks ssqv. the older style with the 2 piece seat and body

[johndoe1003]

i got a racepro type s wanting to change it but yeah, its mounted via a piece of hose. wouldnt of thought itd leak....

[PhatRS]

Sounds like a coil pack to me, maybe AFM but more than likely coil pack.

[johndoe1003]

it does have miss on occasion at idle too so hmm that is an idea... it did come with a spare coilpack and set of plugs too so probably should have a look