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View Full Version : RB25DET Neo into S15 running issues.


nichthen
04-29-2019, 02:23 AM
Hey guys, having a little trouble getting my RB25DET neo S15 to run right. I believe it's a timing issue.

Info about the car.

JDM SpecR S15 with an R34 RB25DET Neo engine. Wiring professionally done.

IACV and AAC Valves removed and blocked off.
Brand new plugs gapped to .8mm
No air leaks
Tried 2 AFM's
Plenty of good fuel plus good fuel pressure.
Spitfire Coil packs tested, injectors tested.
tps voltage @ 0.45
Stock ECU, Freddy forward facing plenum, Turbosmart FPR1200 with a Walbro 460 fuel pump, FMIC w/ 3" piping etc etc.

Following the FSM to set the timing by warming up the car, unplugging the TPS and setting the idle to around 600 - which i use the throttle body stopper Phillips head screw to do, hooking up the timing light to the blue loop wire on the coil pack harness (and also went straight onto #1 cylinder wiring too). With the timing light on the pulley marks, its jumping all over the place. I get it as close to 15 degrees as possible but when plugging in a laptop its jumping around terribly.

When I plug the TPS back in the timing is reading 30+ degrees. The only way i can get the timing back to around 15* is if i completely turn the TPS one way giving the ecu an apparent 0.12v of power.

The car idles okayish, sounds like a slight miss when idling, stalls when revved most times and instead of coming back down to the desired RPM it was idling at before it will just die. When i try to actually drive the car, it doesn't like to even rev with any sort of load on it at all, sputters and dies, laptop says its in the 30-40* timing range when it does have load on it, doesn't give much power to the wheels.

Shouldn't the car still read 15 degrees when its idling with everything plugged in? What have i missed here.

So in a nutshell, car doesn't want to drive, and doesn't stick to its timing at all when a TPS is plugged in and adjusted to 0.45v.

Kingtal0n
04-30-2019, 12:17 AM
first, timing light pickups are usually 1-directional. Meaning you can flip the pickup and get a wrong timing reading. Perhaps you simply put the clamp on backwards....

Next, when the tps is disconnected, usually the engine will hold a timing value steady. if it does not, try a different timing light. If that doesn't help, try lowering the idle.

nichthen
04-30-2019, 03:02 AM
first, timing light pickups are usually 1-directional. Meaning you can flip the pickup and get a wrong timing reading. Perhaps you simply put the clamp on backwards....

Next, when the tps is disconnected, usually the engine will hold a timing value steady. if it does not, try a different timing light. If that doesn't help, try lowering the idle.

My timing light only works one way, and unplugging TPS does nothing, still jumps around. Lowering idle does nothing, still jumpy. went all the way down to 400 or so aswell.

i hate this car.

feito
04-30-2019, 08:17 AM
What harness are you using?
Also, is your bov recirculated?