ECU Limp Mode (Cannot Connect)

[DT444T]

I have tried two different ECUs now, and each time I am getting a solid read light from the ECU LED. I had an electrical engineer and an IT friend of mine install the board both times, and neither time I can get the consult to connect. I am able to connect the consult to a non-Nistune board, but not the one that has Nistune installed?
When I turn the key to ON, the electric AC fan blows continuously and car runs 10:1 AFR.

What am I missing here? I have read through "the documents" and nothing is wrong with this install as far as I can see.

-Jake

[Matt]

if it works with the EPROM chip, and your wires are in the correct order...

check ECU part number matches board number
check PGM jumper not soldered on board

if both those things check out can try exchanging boards?

photos of install would be handy so we can try and see any problems

[DT444T]

The connection between the gray and white wires has been fixed, but nothing works. AC fan still comes on full when in the on position, 10:1 AFR, and LED stays constant red.

[skyline_stu]

The soldered add on pins on the top side look, how should I say, AWFUL!!!

You need to remove the A-D pins, clean the conformal coat of the board with acetone, re-insert the wires and use enough heat to make the solder flow onto the compponent side of the PCB.

while the wires are out, check with a multimeter that there is continuity on the pins - through the 4 pin header there are visible cut-outs, use a fine pointed meter probe. . WIGGLE THE WIRES WHILST CHECKING PINS ONE AT A TIME. they should produce a continuity or less than 0.1 ohms resistance

Stu

[DT444T]

I'm going to need a more thorough explanation on what you mean, exactly.
What are the soldered add on pins? Is that the 4 wires that were soldered? Because those have been fixed so there is no bridge between them.
I don't know what "top" and "Bottom" are without some sort of frame of reference.
Sorry to be such a newb here, but I'm definitely not an electrical kind of guy.

[Matt]

TOP = top side of ECU where the nistune board plugs in and you can see all the chips etc are

I agree with Stu where you have soldered the 'CPU connector' in which is the 4 cable plug there are several problems
(a) solder has not flowed all the way through
(b) solder has not melted nicely and looks like the wire has been moved / not enough heat
(c) looks like there could be a short between (B) and (C) from that first photo

Use acetone/paint thinner and a brush to clean away the conformal coating on the circuit board
Get some flux from a electronics shop and put on both top/bottom of those connections
Reflow the solder so it appears nice and smooth and so there is no possibility of a short

[Matt]

Also compare your soldering against the factory soldering near resistor R661

You can see nice smooth solder flow on that resistor, and the other soldering looks like it hasn't been soldered at all

[louiswun]

The problem might be on the solder of 28 pin socket,
even if the solder looks good on the back side of the ECU,
it might not perfect flow to the surface side.

Just try it, use the solder iron to melt the 28 pin solder again.
On each pin, let the solder iron stay on the solder for 2 seconds.

[DT444T]

Ok, I re-soldered it, and have had no luck. Tested for continuity and my friend said it was good. What can I do here? I'm home for the summer without my car so there's nothing I can do right away, but could I send it somewhere when I get back to have the board tested/installed into my ECU? I'd REALLY like to get to drive my Z again...

[Matt]

two things you can do right now
(a) take photos and post them here
(b) install your factory EPROM chip back in the socket that is installed and see if that works now, then let us know

after that will work out what to do from there

[DT444T]

two things you can do right now
(a) take photos and post them here
(b) install your factory EPROM chip back in the socket that is installed and see if that works now, then let us know

after that will work out what to do from there

I have installed the factory chip before, and the computer will connect to the car, but obviously can only read parameters. The ECU was already chipped when I bought the car so I know the 28 pin connector is installed properly. When I put the Nistune board in, I cannot connect to the car. I didn't bother to start the car if it wouldn't connect. One thing that happens when I put the board in and turn the key to ON is the electric fan on the radiator/condensor comes on, without the car running. The only pictures I have are the ones posted above. Nothing I can do til August since I'm 1200 miles away from my car. I just want to know what to do when I get back.

-Jake

[Matt]

You can send it through to myself or see if a local distributor is willing to look at it for you

I would be checking those 4 cpu wires firstly if it arrived here since its the only issue causing your limp mode (hence fans, red light etc)