Rb25 Swapped R32 Issues.

[1990R32]

Hi everyone,

I just completed a RB25DET swap into my R32 due to my rb20 having a spun bearing.

car starts and drives fine until about 30min into the drive. basically it will start bucking if you drive it under 2,000rpm and coming onto boost at about 4,000rpm it will die off and then hammer until redline with a missfire / popping noise. i also found one coil pack was cracked so i replaced it and taped them all up to stop them arcing on the bracket. the pop seems to have gone away untill about the 5,500rpm mark

Its running a Z32 ecu with a nistune and we had a play around with it and we have the top end issue to running too rich on full boost. (10psi on a GT3076R)

im trying to figure out what could cause the bucking issue that i have.

if you try to take off under 2grand it will act like it has no throttle input. but free revs fine.

if you are driving and it dips under 2 grand and you accelerate slowly, same thing, if you just flatten the pedal it will accelerate fine without bucking.

anyone had this issue?

RB25 is out of a series 2 1995 r33 skyline we swapped

injector plugs over

coils to rb20det coils

rb20 harness

Z32 ecu and nistune

spool oil drain

rb20 balancer

all rb20 bolt ons ( alternator, p/s pump, ac compressor)

rb20 gearbox

it is still running a RB20 series one afm and will be getting a z32 one soon.

and is still running the series 2 gear (tps, knock sensors, anything we didn't swap really) VVT isnt hooked up yet either until i send my rb20 ecu to have the nistune replaced as when i tried my rb20 ecu it wasn't getting a tps signal. swapped the ecu out of my 300zx and it runs fine.

Any tips or help will be greatly appreciated.

[Ben C34]

I read a while ago and lack of a speed sensor input causes a delayed weird reaction from the ecu.

Have a search around the the nistune forum or contact mat.

[1990R32]

thanks man,

Will have a chat to matt when he opens back up.