Mail sent to JWT about Z MAF issues

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03-15-2005, 11:22 AM

iansw

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Mail sent to JWT about Z MAF issues

>From: "Ian"
>Reply-To:
>To: Ben <JWT>
>CC:
>Subject: Z32 MAF still having idling issues....Data now available on faster site.
>Date: Tue, 15 Mar 2005 19:26:20 +0000
>
>Hello Ben - this is Ian Sweeney from Seattle.
>
>I've talked to you several times in the last few months about my
>setup but have been unable to get the NProbe data for you so that
>you can diagnose it due to website issues.
>
>However - I now have my website on a MUCH faster link, so you should
>be able to download the NProbe Data I've taken pretty easily.
>
>http://www.cyberhub.net/JWT
>
>Files are basically named what they are.
>eric.xls is a comparative run with another Maxima for control
>testing.
>
>The car's issue is this:
>I purchased a Z32 MAF/Z32 Injector Program for my 97 Maxima (running
>96 ECU).
>Previously I had been running on an A32 MAF/Z32 Injector program,
>and the car ran (runs) great.
>
>I am finding the timing and O2 voltages are way out of whack on cold
>startup, and then when warm the timing and O2 sensor data is better,
>but still not perfect. If you look, you notice that with the A32
>MAF, the O2's read .31 at cold startup (car sitting 5+ hours) then
>slowly raise to .8v. With the Z32 MAF, it starts at .31 at startup
>but then DROPS to .02 while timing appears off and I have to feather
>the throttle just to keep it running. As the car warms up, the idle
>improves, but sitll continues to hunt quite a bit.
>
>Essentially - on the Z32 setup, the car idles rough when warm, and
>almost not at all when cold.
>When cold and driving underl ight load, the car hesitates at low RPM
>but then runs fine above 3k RPM. (Didn't want to do this much as the
>SC is not yet warmed up).
>When warm and driving, the car runs under load fine. Boost feels
>great and mid-range hesitation is nill. Hunting idle still exists
>at a stop, as i said before.
>
>Maybe this data can help you possibly help me diagnose what the
>issue is. I have tested the MAF on a Z a friend owns, and his car
>ran great on it. We also tried his MAF on my setup with the same
>rough idle/hesitation.
>
>I also have checked the wiring signals and made sure that the proper
>wires read the proper voltage in accordance with the wiring diagram
>you have on your site and by comparing the Tomei Connector pins with
>other people from Maxima.org.
>
>Tomei connector:
>White = signal
>Black/White = +12v
>Black = Ground
>Brown = Ground
>
>If I put the A32 MAF back on the car the car runs great even with
>the Z32 Program installed.
>However, the Z32 MAF of course does not run well with the A32
>Program.
>
>Thanks for the help Ben - I hope we can figure this out soon. The
>car runs SO WELL under load when warm and top end feels incredible
>compared to my A32 MAF that is maxing out at about 6k RPM.
>
>Vacuum is at about 18Hg when warm.
>No other Fuel Management devices/electronics are being used.
>

Let's see if Ben can help.....