Z32 MAF on 88NA Board, need Some Help!!!

1SIKZ31 · Post by **1SIKZ31** » Tue Jul 29, 2008 3:16 am

Hey Matt,
Ok I just acquired a 88 N/A Federal Automatic ECU and need some Help.

Where do you install the Zener Diode on the 87 ECU, since the thread you made appears to only show the 86' year model ECU.

Do I just go to a computer store and ask for a "5.1 Volt Zener Diode"???

Also... I have LOW Impedance DSM Injectors, and this is a HIGH Impedance ECU if I remember Correctly, so will dropping resistors need to be installed? If so... Im going to sell this ECU and buy the correct one (low impedance)

Thanks and Please someone help ASAP so I can get my car back on the road.

Edit:
Ok so I figured out what needs to be done for the 87 NA ECU for the Z32 MAF to work shown in the picture below:

But where do you install the Zener Diode to clamp the voltage???

Matt · Post by **Matt** » Tue Jul 29, 2008 11:06 am

The zener diode only applies to the earlier ECUs

- Later model ECUs like the one pictured has the OPAMP chip and supporting components on the main board

- Earlier model ECUs have the OPAMP and surface mount components on a mini board

It is easy to modify the later model ones since you can change the resistors, but on the early model ones we bypass the OPAMP altogether but require the zener diode to clamp the voltage

In short... later model ECUs dont need the zener to clamp the voltage since its already part of the circuit which isnt getting bypassed

1SIKZ31 · Post by **1SIKZ31** » Wed Jul 30, 2008 5:19 am

Sounds good.

Looks Like im selling this 88NA ECU, don't want to mess with having to install dropping resistors. 86NA ECU on its way in the mail... I will post up when I get my car running again, thanks matt!

Matt · Post by **Matt** » Wed Jul 30, 2008 12:30 pm

I would use the 1988 ECU and put the dropping resistors in. Less hassle than installing the zener on the earlier one

1SIKZ31 · Post by **1SIKZ31** » Thu Jul 31, 2008 6:32 am

Matt wrote:I would use the 1988 ECU and put the dropping resistors in. Less hassle than installing the zener on the earlier one

I just ordered 20 dropping resistors, and already bought the 86 ECU, to late now, lol.

Matt · Post by **Matt** » Thu Jul 31, 2008 11:07 am

Yeah I just got the email. Okay see how you go with the 1986 ECU then

1SIKZ31 · Post by **1SIKZ31** » Mon Aug 04, 2008 6:23 am

wowwwww

Ok so I just owned myself.....

me and a friend got the new ECU in, its from an 86 NA Automatic, PERFECT!

Anyways, we flipped it over and solder-sucked all the solder out of the 28 pin EEPROM chip, and we flipped it back over and I used a little screw driver and started lifting up on the chip, well it EXPLODED out of place, and just flew in the air, along the way, I guess we didn't take the solder off completely off ONE of the pins, which resulted in 27 pins coming out cleanly while 1 pin pulled the "copper strand" out of the ECU's circuit board completely out!!!
We are not fucked, but!!! .... we picked it up in the air and put it in to the light and traced where the copper strand went, it went to the 24 pin chipset next to it, so we ran a jumper wire from point A to point B and we installed the rest of nistune, including doing the Z32 MAF mod and the zener diode, car started RIGHT UP!!!!!

its aliveeeeeee!!!!

I have not driven it, only had it idle, but so far so good, I will update you soon matt!

Matt · Post by **Matt** » Tue Aug 05, 2008 12:28 am

That can happen sometimes with those older ECUs. You should heat stuck pins whilst trying to pry the chip to prevent it

Jumper wire between the track points is suitable. Good stuff you got it all working. Hopefully it runs okay now

What K constant and latency did you end up with for your setup?