View Full Version : RB25DET No Start and Fueling Issues

06-13-2022, 01:14 PM
Hi everyone, my friend recently dropped in his RB25DET S2 into his S13 hatch and he's running into some issues.

The fuel pump will only prime once when switching between the accessory position and the on position for the key. When the battery is disconnected to reset the ecu, the fuel pump will prime but will not prime another time until the battery is disconnected.

Another issue is that the starter will not crank the engine. We've verified that the starter still works and we can hear the relay clicking but will not crank the engine.

Also, the fuel pressure drops off after the fuel pump primes. The gauge reads about 20 psi, and drops below 5 psi in less than 10 minutes. I've read that a faulty fuel pump or fuel supply/return lines are misplaced can cause this.

The engine was known to be running before it was dropped into his hatch (was from another car that got written off). He also repositioned the relay boxes (cut and extended wires). I suspect that the ecu is fried and the fuel pump or fpr or the fuel supply/return lines are swapped. Another assumption I've made is that the chassis harness could be faulty? The relay boxes are repositioned and could that possibly be the issue?

Not entirely sure how to go about this and any help is appreciated. Thanks

The car has:
Wiring Specialties Pro Harness for swapped S13
BF ecu - RS Enthalpy tuned
R8 Coil Packs
Z32 Maf
CX Racing IC