RB25DET Z32 ECU, Fuel Pump Activation.......

[doyle4281]

Hello all, I am sorting out some of the last details of my project, and I am currently having a minor start up issue. The engine is a series 1 RB25DET,the car is an S14 240SX, with a Nistune equipped Z32 ECU. After sitting over night or a few hours, the engine is rough to start, requiring excessive cranking, and sometimes needs some opening of the throttle. Something I noticed is that the car starts much better with the factory ECU installed. After starting the Z32 Nistune ECU runs the engine great, and the idle components seem to be functioning properly. Now, a difference that I did notice right away, was that the Z32 ECU only primed the fuel system for 2 seconds, and the RB25DET ECU primed for a substantially longer time. Has anyone else run into this issue, or have any input?

[jabran]

sounds like the z32 is in limp mode, have a look at the soldering in the z32 ecu and check fro damaged tracks.

[Eric]

the Z32 ECU will prime for approx. 1 second after ignition is turned on...this is normal operation and not limp mode.
Once the engine is cranked it will switch on the pump again.

Maybe the values in the (cold) crank table need some more adjustment.