Once again a run down of the performance mods: - Engine - Engine was bored 0.030 over, Manley H-beams, DSS blower pistons with 8.5-1 compression. - Vortech S-Trim Supercharger - 42lbs. injectors with a lightning 90mm Mass air meter - Walboro 255 fuel pump with T-rex pump - Flowmaster mufflers - Bassani X-pipe - FRPP shroty ceramic coated headers Problem: Around 4000 it starts to stutter and hesistate....and falls on its face. It's only boosting 5 psi now and I have no clue why.... I had a FMIC on it and was having boosting problems so I completely took it off.... and now running like the kit came with.. and USE to boost 10 psi... Now and with the FMIC it falls on its face at 4000-5000 rpms and won't boost over 5 psi or so. I have no clue why and it's really really bothering me. It also has ACCEL wires and pack... do those suck? Could they be the reason? Could the stock vortech bosche by pass valve crap out on me? Could it be spark plugs? I have pretty damn new NGK TR6s in it... (less than 2k miles) Any help please? Its really pissing me off.. we went out running tonight and I lost to EVERYONE..... (a few pullied terminators , turbo swap wrx) I'd out launch the hell out of everyone big time with my et streets but after that it fell on its face and I'd lose the race... pisses me off... :slap:
did you ever get the boost issue fixed after you add'd the intercooler?. Gotta wideband? Has anyone said anything about smoke coming out of the exhaust? if so what color.
I took the intercooler off and it boosted like 9 psi after the stutter.... Put it back on and I boost around 7 or so...after the stutter... No wideband... I need to borrow one.. Im thinking its just dumping all kinds of fuel.... On the way home last night when I down shifted it backfired a few times.... INSANELY loud... No smoke really noticedl.
def. invest in a wideband. you could have a vacuum leak, boost leak, fuel issue.. who knows. hard to say w/o seeing what its doing. I do know on my setup w/ 15psi, that if i hit 4k rpm + the car would stutter and very slowly rise in rpm's. I was getting spark blowout. I put a KB boost a spark on and no issues anymore.
My buddy has an extra lightning maf laying around. Gonna toss that one on just for grins.. check the plugs and replace them probably..and try to borrow a wideband.
I already got the MAF on the car... I meant just replacing it with his... see if my is just bad or needs cleaned or what not..
Check engine light on? If so, the computer will keep on messing things up until you either clear them by unplugging the negative wire for a while or fixing the tune or plugging the 02 back up if you took them out... Maybe a bad tune with too much fuel or how about inj`s? Maybe one or more are broke.
Im still thinking its a lean condition or ignition problem. get the Xcal 2 and datalog the injector duty cycle and see what they do thru a WOT run.
Probably wont be able to get the XCAL till late June Lean condition eh? I was thinking really rich... it backfires on the decel and after getting on it.. I can smell fuel so bad my eyes water some times...
which way do you have the stock Bosch BPV hooked up? do you know which model it is? I had a very similar problem with boost using the one that came with the kit. I was blowing it open under boost. under the advise of my tuner, I switched to the bosch 114 BPV and reversed the way it was hooked up. ( so the boost kept the valve closed) Also I had similar problem with the stumble around 4500. We went through a ton of things, and finally realized it was the coil packs. Mine too were accel. I switched to MSD and it pulled to 6500 with no issues.
I still have the regular by pass valve. I was gonna buy a upgraded Forge one.... Is there any way to test the by pass valve? Im not too sure thats the problem.. I do have ACCEL wires.... how much are those to replace?
for the BPV, the stock one looses boost around 6-7 psi. to help make sure the end of the BPV that sees the boost is setup to hold the valve closed. Basically the boost will hold the valve shut, until the vacuum opens it. I would upgrade it asap. the bosch 114 is like 40 buxs. I replaced my wires with Taylor wires and MSD coil packs...its not cheap, you would have to shop around.
I know you gave me a link to the by pass on ebay before.. .but the only ones I can find now are like $75... Also another question : Would a faulty TPS sensor cause any of my problems... I KNOW mines jacked up... the idle hangs at 2k and slowly falls when I come to a stop. I put it on my buddies car that never did that... and his did the same thing... I got a new one coming though...
just curious, but have you had it tuned lately? the BPV can be bought at any VW dealer. Its a stock valve for the late model 2.0 turbo.