Nistune Forums

Okay, next question. Is there a default setting for the Idle Air Valve? I got 1000cc injectors and fairly big cams, I am not pulling much vacuum. When I start the car, the idle fumbles around at about 800rpms for about 5 seconds, then the IAV opens up, the engine idle ups to about 1400rpms until the car fully warms up, then it comes back down to about 1000rpms. So that is the situation. Is there any way to have the IAV default to wide open so that when I start the car, the idle is already high?


Next mini-question. When I stop at a light, my car is idling (1000rpms) and trans is in neutral, I get ready to go, I push in the clutch, and slip the shifter into 1st gear.... when I shift into first the rpms drop and the car stalls. Is there a setting to stop this stalling? or do I just need to raise my idle?

not sure on the AAC control on the Z32. from memory (need to check) its consult settable so if we traced the code where its set there would be memory addresses where it is accessed but not sure on the conditions

i dare say that when you go from the idle enrichment tables to main tables (non idle) that its probably going too lean perhaps. what do your AFRs look like when you perform this transition?

Increasing idle control tables (which changes ignition timing) is a short term solution here

What happens when you turn engine off after first start and start it again, same problem??? If second start starts the same as first, I would eliminate a table problem on ECU and look at the IACV itself. If engine starts ok, then I would look at start up tables, like first time, etc.

Sometimes the IACV valve gets sticky, so needs to be cleaned. On some IACV valves, can adjust a screw on the IACV valve to fully open valve inside IACV after cleaning it. In some cases IACV valve needs to be replaced. Also check throttlebody adjustment.

is this car an auto ? is so it may need a high idle and possibly a stall converter to raise the stall point.. Sounds like something is going on in the start settings I think that there is a map that only runs for 5 seconds after key turn.. not sure though.. do you have the standard throttle body/s on it ?

Okay, I changed my user settings. I should have my basic mods in my sig below.

Edit: In case it doesn't show. Here are the goodies:
Restored 1989 BNR32
New N1 bottom, GTK-850 turbo, Twin Tial 44mm WG's, 1000cc injectors, HKS 264/272 Step 2 Cams, single 90mm throttle, Rear OS Giken Super Lock, Front Nismo 1.5 way, Trust deep sump, HKS VPC & GCC, couple other things,**NISTUNED**.

I cured the stalling while shifting into gear. I adjusted the target idle from 950 to 1000rpms. Later I will up the target idle at 60deg. I think it is at 1200rpms now. Seems good so far.

Still hard to get the car to idle up on a cold start. All in all, my car is idling lower than many GT-R's with big cams.


Is there any setting for increasing fuel when the throttle is pushed, just the throttle? With 90mm throttle, I am hitting a big lean spot when the throttle is just barely pushed - probably too quick for the MAF (map) sensor to react. I need a spurt of gas right when the throttle opens.

Throttle enrichment, increase fuel tables.