View Full Version : RB25 w/ GT30 Idling and cutting off issues

08-31-2013, 08:56 PM
Problem: Motor takes multiple times to start and get running. Harder to start with MAF connected, easier (usually within 2 cranks) starts up without the MAF plugged in. Once running it struggles to go past 3500k rpms, when it does, it shuts off soon after.

A little rundown on the motor:
Bought it already built with 3k miles on it. The motor was tuned before hand by the previous owner. Just threw it into an S13 chasis. The exhaust system is not finished as well as there is no widebeand. It is just down pipe with an open bung hole. Keeping in mind I think it is on the stock fuel pressure regulator as well. There is nothing else done to the fuel system other than the aeromotive fuel pump.

Information on the engine:
Series 1 RB25 W/ CX Racing GT30 turbo
Brand New Aeromotive 11141 Fuel pump
Tuned stock ECU (RB20 ECU)
Manual Boost controller
ACL Main and Rod Bearing
ARP Main and Rd Bolts
ARP Headstuds
Weisco 8:4:1 forged pistons
Stock Rods
Freddy Intake Manifold
90MM Billet Throttle Body
800CC Injectors
Z32 MAF Blow through
GT30R Top Mount CXRacing Turbo
Tial 38mm Wastegate
HKS Sequential BOV
Full 3" V-Band Exhaust

Any help would be appreciated. Thanks!

09-02-2013, 01:27 PM
No one? Wow. If anyone can point me in the direction of a good reputable shop around the Melborune/Central Fl. area that would be appreciated too.

09-04-2013, 08:59 PM
Tuned stock ECU (RB20 ECU)

This could be your problem. Also, the 90mm is hard to get right with your TPS and SAFC. It will take a bunch of street tuning.