Testing P72 S300

[Dunc]

Background:
- Car is a 1997 Integra LS/VTEC with Hondata S300 using an OBD1 conversion harness and a P72 ECU.
- Ran flawless for years. Sat untouched for several years. I'm ready to sell and move on to other stuff.
- Had some horrible (i.e. undriveable) bucking/stalling issues. Fixed it from what I thought was faulty injector harness wiring. This was after replacing damn near everything. Ignition system, fuel system, injectors flow tested, TPS, MAP, everything. The driveablity was good after I corrected faulty injector wiring, but that was short lived.
- VTEC stopped engaging, and after I tried a new vtec assembly which didn't fix it, I gave up and gave the car to the original tuner to see if he could figure it out. I had enough of it by then.
- While he was test driving it, the car died on him. It starts but dies as soon as you touch the throttle just like it did awhile back so it appears as though the stalling issue is back again. He is leaning toward the ECU being bad which makes sense to me and would explain everything. He is saying the sensors and calibration all look good.

Question:
How do I test the ECU? Is that something you just replace? I haven't looked at the ECU in a long time...can the S300 be swapped over to a virgin P72 ECU? By swapped I mean just unplugged the S300 and put it on the virgin ECU's circuit board. Or is that something you have to send to Hondata and they install on the circuit board?

My only reservation about trying this is the cost really. I am not interested in spending $500 for a new S300 from Hondata on top of whatever an ECU would cost which I'm guessing is another couple of hundred. I just don't like taking $6-700 shots in the dark for something that will hopefully fix it. I wouldn't care about the cost if I knew this was definitely the solution.

My truck is really wants the Integra to work and get sold so it can get a set of turbos :)

[Spunkster]

I would highly recommend that you try the ECU and s300 in someone else's car that has a Hondata system and just load their calibration into your ECU and see if it runs properly.