Nistune Forums

Hey guys just got my car running after a full rebuild and put in a nistune with stock map, modified for the afm.
However it starts but as soon as throttle is on it stalls.

I believe I need to disable the o2 and adjust the k Constant.

However I was wondering if anyone can confirm anything specific I need to do, keep in mind this is just so I can baby it around to run it in then I will pay for a proper power tune.

Current config;
Stock Injectors.
Adjustable fpr
Tomei poncams
Forged pistons
Gt35 turbo.
External gate (7psi spring)
Z32 afm in blow through configuration (hot side unfortunately as I had a hole for my bov already there and it's only temporary until I go power tune I will install a hpx maf.
No bov.

Cheers guys.
Brendan.

What car / engine?

Hey mate
That probably would have helped, stagea rb25det neo

I'll explain what happens.

Afm has been modified to z32. Car idles but doesn't accept throttle, just dies off. Change k constant (excessively) and it doesn't idle well but revs and dumps fuel, (lots of black smoke).
Adjust it slightly and it makes no difference.

I can't get into a tuner until next Thursday so I was hoping it was something I could sort out myself and save some cash.

Do you get an AFM voltage reading in Nistune? Is the Z32 MAF wired pin properly? At this stage sounds like it might not be

Yea mate definitely getting a reading.
Blew air through it using compressed air before installing and installed the right flow direction and nistune shows voltage change depending on airflow and throttle.

Attached is the basic starting point. Z32 MAF on WC34 base image. Try again and adjusting K

If still issues then look for any airleaks

Hey Matt will try that.
You probably remember my ecu, you fixed my mates great soldering and retuned it with z32 afm change on it. Would this differ from what you are providing Me here?

Also how much should the k const be adjusted.
Tried again last night, at a low level it made no difference, at around 190+% it was able to accept throttle. But drove funny and had flat spots.

Sorry forgot to mention my ecu is ov812

+/- 10% would be expected maximum. This tune would be same as already on there. Something else doesnt seem right then. Check air leaks and perhaps try another Z32 MAF if possible

If not try the ER34 MAF again with stock map in the ECU

Matt wrote:+/- 10% would be expected maximum. This tune would be same as already on there. Something else doesnt seem right then. Check air leaks and perhaps try another Z32 MAF if possible

If not try the ER34 MAF again with stock map in the ECU

I don't have the factory maf, sold it already and to use another z32 would be painful as it has been siliconed into the cooler pipe to secure it.

I will check for leaks but i don't think there are any and ill reload the base map and mod for z32 again just to make sure nothing has been broken in the process.

Does anything usually have to change when using a afm in blowthrough?

Not normally. I went from blow through to suck through on my R31 with minor changes to K constant

Okay I really am not sure what is going on.
I started from scratch;
stock map, changed to z32 afm, and played with k constant (default value (at 100%) was quite high compared to last time) and managed to make it run, up and down the street pretty well, very slight hesitation and not over fuelling and no upper rev's flatspot.

I turned the car off (without burning to ecu as I was under the impression AFM change and K const changes were updated on the fly), however started it again and nothing, had no AFM set at all and didn't run properly.
I couldn't replicate the settings I had previously and forgot to note down exactly what I did, which makes me sad.

I give up, nistune tuning isn't for me, it's booked in for thursday with someone who knows what hes doing so ill leave it to the pros!

Thanks for all your help Matt

Burning keeps the tune in the ECU for next time. If you dont do this then the changes get lost after turning off the vehicle (this is covered in the software manual!)

Yeah I had a bit of a blonde moment haha.