Type 1 tuning issue DFCO related

[ihiryu]

Hey guys, I have an 87 300ZX turbo, I have a nistune type 1 board on an 87NA ECU.

I swapped the ecu, and put on an 87NA o2 sensor, along with the idle air control valve.

The car is modified with 550cc injectors, a 6262 turbo, stock MAF.

The car idles decent, but no matter what pulse width it is at, it will start going crazy (on the wideband gauge). It'll randomly idle nicely at 14:1, then all of sudden it'll go rich, then all the way lean, despite what I've changed the pulse width to.

And this happens below 2500, when it's above, it seems to run great under boost.

Also, when I let off the gas, it doesn't go into DFCO, and I can confirm this because it pops and backfires on decel, plus my gas mileage is horrible, and the wideband never goes all the way lean when I let off.

I'm seriously frustrated with this whole nistune thing! It seems like a great management, and everyone is having success with it, but me.

[Matt]

Some things to try

1. Calibrate your wideband sensor
2. Disable O2 feedback (set feedback temp to max) temporarily whilst resolving the issue
3. After both get a log file of the idle with AFRS included and gradually after idle increase throttle during the log

Post the log here along with your maps and we can have a look at it from there

[ihiryu]

Matt,

I tried both, disabling o2 sensor, and enabling it, and still no DFCO.

When I get a chance I'll post the log on it.