Nistune Forums

Hi guys just looking for someone to join me in my nightmare. We have a r31 rb30 na with a turbo bolted on, front mount, 380cc injectors which somehow are supposed to flow 550cc, and a z32 afm.
First issue: Car will start and idle nice from 20 degrees c until 40 degrees c, then carry on hunting until 61 degrees at which point it smooth out and be a dream. You can drive the car when cold and notice no bad behaviour.
Second issue: The car will not rev above 5000rpm under load. If the limiter is set to 5000 it will get that far, if the limiter is higher it appears to only get to about 47-4900 rpm. Not sure if the injectors are losing control, also thinking possible coil breaking down. Any suggestions would be appreciated. I have tuned the car with three different starting k values and fuel maps to suit, all ran the same. Attached is the latest tune, start up and warm up drive log and then a quick drive up the street log.
Any views, opinions or help is appreciated. Thanks Damien

Rev limit is interesting. I dont really see the ECU cutting here. I've loaded in the tune onto the bench and can consistently hold 5900rpm and then it cuts afterwards. I suspect perhaps ignition breaking down perhaps (try swapping coil, cleaning distributor cap and plugs)

You will need to watch the AFRs as the temperature changes and keep adjusting those warm up tables until you have got it. Z32 AFM does some wacky things to TP and throws out the cold start a bit so these need adjusting to make up

I gave the car back to the customer, drove home fine(still cut at 5000rpm). He parked it up, an hour later went to go for a drive and then would only rev to 3500rpm. Left it for a day and now it revs back to 5000rpm again. Will be trying a new coil next week and also thinking i gotta go looking for a bad earth or something along those line. New cap, leads and plugs already been fitted prior to tuning
Damien