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View Full Version : S1 RB25DET issue..


BHarvS14
02-13-2014, 12:27 PM
95 s14
s1 rb25det
basically all stock
fuel psi 43(w/o vac)
10psi boost
251whp 233lb tq

long story short i finished the swap couple years ago, ran poorly(75whp poorly).. eventually got it fixed. swapped stock rb25 ecu with a z32 ecu done up by RS Enthalpy, ran like a a champ.. then he said id probably need to swap my plugs out since they're all fouled due to it running poorly for awhile(ran rich, backfired like crazy). so when i got home, i was like hey might as well since i have new plugs on me already.. OLD plugs were bcpr6-11 gaped at like .024 then got new ones exactly the same, same gap.. now it sputters and shakes at idle..you can hear it gargling.. but once you give it gas it doesn't..

im trying to chase this problem down, just want my rb to run properly ha. i do have a leak at the turbo inlet(waiting on new gasket to arrive) maybe the problem? also when i had my car on the dyno, i was told i might need to get new coil packs.. only like 500$.. real cheap... sigh.. maybe that's the cause? seems like its misfiring for sure..

im no pro but anything will help.. thanks.

Boostd2
02-13-2014, 02:10 PM
I'd suggest you Gap your plugs @ .030 ~ 028. Also check your base timing and tps voltage.
If your tuner suggested new coilpacks then by all means change them and then report back.

FutureFab
02-13-2014, 03:03 PM
You are not running enough boost for that plug gap, do what boostd2 recommended.

I ran buick grand national packs on my rb25. Could notice a difference just driving up the street, not even in boost. Much more crisp throttle response. There are other options too, like the gm coil packs. You will have to do some fab to make them work, not plug and play. Well worth it to change the 20 year old coil packs.

Ilya
02-13-2014, 04:28 PM
Since replacing spark plugs on the RB requires basically to take apart half the engine, I recommend going over everything again. Poor connections, vacuume leak, blow off valve, piping couplers. Also since you did touch the coil packs, I'd check them too. Get some dry ice, and put it into your intake piping to see where the smoke comes out.

BHarvS14
02-13-2014, 10:54 PM
sounds good to me. i appreciate the help. lets hope i can figure something out..

Ilya
02-22-2014, 10:03 PM
Lets not make it one of those forgotten threads without results. RESULTS?

BHarvS14
02-22-2014, 10:13 PM
im still waiting on raw brokerage to respond & send me the coil packs. Inlet Gasket & boost controller should be in monday. As for poor connections, Vac Leaks, BOV, Piping.. everything seems tight and leak free.. so im hoping its just spark plugs and coil packs.. im getting BKR6E instead if BCPR6E and gapping them at .030-.028 & split fire Coilpacks.. sigh..

BHarvS14
02-28-2014, 11:31 AM
alrighty.. split fire coil packs in, with new plugs gaped as recommended.. runs a lot better but still has a random "hiccup" here and there(can hear through the exhaust) also the engine shakes alil still not sure if thats uh normal for a RB but checked out my motor mounts and theyre still looking good.. looking more into vac leaks and swapping out the T3 inlet gasket & hooking up the boost controller..

redline racer510
02-28-2014, 03:32 PM
Check your turbo compressor outlet gasket as those seem to have problems as well.