Originally Posted by
daveracer So i'm pretty stumped by this. My P10 VE-T doesn't idle correctly. Let's rewind to when i had just put the VE in the car.
I install the VE engine into my P10, without the turbo. Car idled wonderfully. Rock solid at 900rpm's without fail.
At this point, i installed a Z32 MAF, 370cc injectors with a nismo FPR @ 4-bar, with a fuel pressure gauge and update the program on my Calum ECU. Idles and runs fine still.
So i install the turbo onto the car (JUST the turbo, manifold, lines, downpipe) and leave the charge piping off. I lengthened the o2 sensor. I start the car up, with the regular intake tube going to the maf and to a filter, like it was N/A. The car idles like junk. Fluctuating from 1000-2000 rpms, up down, up down. Pretty methodical actually. LOL.
So a few days later, i install the charge pipes and the rest of the turbo setup. Car idles the same, runs like a bat outta hell, but idles like crap.
So at this point, i figure i would install a 300zx o2 sensor, and get rid of the lengthened one. This made the car run a little smoother, but didn't help the idling issue.
So where did it go wrong? Fluctuating idle (worse when it's super cold out), chugging along between 1000-2000rpms, the on/off throttle is horrible. Car is very jerky.
I have checked, via my Calum ECU:
TPS voltage is good
MAF voltage is good
Temp sensor seems to be working fine....
Front o2 has got to be fine, since it's brand new
Throwing codes for:
Rear o2 sensor (not running a cat)
Crank Position Sensor (im running a b13 trans)
Any idea? It pretty much runs great, but this idling is getting to me. At some points when it's really cold out, it will idle at 3,000 rpms....then i'll shut the car off, wait 5 seconds, turn it back on and then it will fluctuate from 1000-2000rpms. It's got to be electrical...but where?
Oh yeah, the car won't go into idle adjustment mode via Conzult, and the idle screw does nothing (used to, doesn't anymore)
Sounds to me like an AAC/IACV issue. Seems to be happening frequently with turbo setups. Is your calum ECU a basic or RT? Could be that you need to play with your cold start idle values? When you warm the car up to operating temperatures, what happens? Does it continue to fluctuate?
Unplug the IACV/AAC and see if the idle still bounces around a lot. If it does, unplug the TPS and see if the idle stabilizes.
Sometimes you can't force the car into timing mode if the ECU is trying to hunt for a stable idle.