Compatibility problem with '96 TCU?

[masoQist]

I recently installed a '92 NICO ECU and a '96 TCU in my '90 Q. The TCU is 31036-67U00. Everything seemed to be working OK, until I tried some WOT runs. The power seemed to be reduced. The effect was accentuated by full power returning in bursts that lasted about a half-second. Running all the way through second gear, there would be about three of these brief bursts. It felt like someone turning on and off about 50 HP or more, like a light switch. I immediately suspected that the '96 TCU may be the problem. I swapped the original '90 TCU back in, and everything was back to normal. My guess is that the '96 TCU was sending a retard signal to the ECU in an almost continuous manner.

I found only one other example of someone trying a '96 TCU. He experienced "hesitation" and a lack of "smoothness".
96-tcu-into-92-q-some-hesitation-when-d ... 26668.html

Since there are multiple reports of the '94 TCU working with the earlier ECU's, I'll be looking for one of those. If anybody can post the part number for a '94 or '95 TCU that is verified to work with the 90-93 ECU, it would be much appreciated!

[OwnerCS]

I've tested TCUs from 94 and 95 models with my recently purchased NICO ECU without a problem. Though I haven't tried a WOT test..

The part number that I have been using is:

31036 68U10

A64-000 P54 3XU4

Also, Heath has some TCUs for sale in the classified Infiniti parts for sale section..

[masoQist]

I bought Heath's '94 TCU. Fixed the problem. 1-2 shift seems smoother, but I may be imagining things. Another strange thing I had not mentioned, is that the '96 TCU shifted at about 6500 RPM. Now, the car shifts at over 7k

[Q451990]

Sometimes even I don't appreciate this site as much as I should!

I was at the Pull-A-Part today with a '96 TCU in my hand, and decided to check it with my phone. I looked at a listing for a 94-95 that I have on eBay, and noticed the part number was different. So I googled the part number and up pops this thread! Now the TCU is sitting in the passenger seat and I didn't waste any $$



Heath