Rb25det Minimal Power Under Boost/idle Fluctuation

[BlackLine33]

Hi guys,

Been driving my 33 for a while now and it has been faultless. However the other week I was cruising at 60 and it felt like the engine power had dramatically decreased..almost cut off. I tried to push down the accelerator harder but the revs were struggling to increase and the car was in a jerky motion. I pulled over to the side and the idle was fluctuating from say 200, where the car would almost die, to 1200 rpm. After a few mins the care felt okay to drive again, but not 100%. Since then, if I don't use boost then the car will drive okay. Once I hit boost hard (1st gear pulls) and while im still in boost, it sounds like the turbo is whistling but the car isn't accelerating much. Then after this short spurt of boost the car will feel sluggish, jerky, and very minimal engine response from the accelerator. The car will end up regaining some power after a couple of minutes but not fully.

Prior to this happening I had an aftermarket bov which I had to change back to factory. I thought it could be the issue so I changed it back to the aftermarket one but the car still acts the same. Fuel pump is a wallbro 255 and is fine...still primes when turning the ignition to ON. I'm still thinking it's some kind of fuel related issue. Maybe turbo has had it? Care to shed some light guys? Thanks for the help.

EDIT: i have yellowjackets with the standard plugs that rb25dets use.. replaced the plugs only 2000kms ago

Edited May 30, 2015 by BlackLine33

[GTSBoy]

Pump is either weak, or you have put a load of crap fuel in it and blocked the filter or injectors. Either that, or it's a spark thing.

[CEF33Y]

Mine was doing similar things. Turned out to be dry solder connections in the afm.

Check the main pins into the board, and joints on the main board, I had some there too.

[FordyR31]

You may have a boost leak, split line or something. It could explain why it's OK until it sees pressure then goes funny. I had one a couple year back and it drove fine until it saw boost and would rub terrible. Are you getting any black/dark smoke out the back when it does it? Mine turned out to be a broken rubber plug which was being used to block vacuum hose attachment off the comp housing of an OP6 turbo. Put a new plug on it, problem gone.

Edited June 1, 2015 by FordyR31

[Trex]

Check afm. If it's the same problem as mine the exhaust note has probably changed tone also.