okay, Im new to the site. I am also a member of 25rs.com, but I have recently swapped the N/A ej251 with a 2003 ej205. It has been in my car for about 8 months and until this morning, hasn't run well. I found out it was an electrical problem in my harness and that's all straightened out now. No CELs! But I think the car is in limp mode. Car idles and drives normally until about 3500 -4000 rpms and the hits what seems to be a revlimiter. Boost plateaus around 8-9 psi and it seems to lack power all through the power band. I am new to the turbo world, so I'm not sure why its doing this. Also of some note, there is a VERY LOUD sucking sound (leak I'm assuming) from the left-hand (standing in front of the car) TGV motor. The leak is from the vent on the bottom. The right hand TGV motor is on the back, and the vent is facing upward. But not sucking air. Only the left one is sucking air. I put a piece of electrical tape over it and it helped smooth out the idle a bit, but still seems to be in Limp Mode. Any help would be much appreciated!

 

no one?

 

Kinda sounds like a VSS. (Vehicle Speed Sensor) My RS did the exact same thing. bucked and felt like fuel cut mid range on the tach. replaced VSS and never had a problem since them (20k miles)

 

how is the MAF? cleaned or plugged in? maybe your boost solenoid....usually a CEL will kick on if its in limp mode i believe..

 

+1. CEL, ABS and DCCD will all be on when in limp mode....IIRC

 

Okay, possibly the boost solenoid I guess. is there anyway of checking that?

 

Its an RS but has a complete 2003 WRX swap.