Hi Road and Track,
 
I did some more tests but before setting out to get another ECU or having this repaired I just want to make sure its the ECU.
 
Okay so this is what I've worked out. The exhaust temp light coming on is correct. The LEAN condition is causing it.
What I did is let the car reach correct coolant temperature. Then I reved it at 2,000rpm to 4,000rpm at idle. It gets to a point where the light dimly flickers on then off (after say 5mins) when the cars at idle (kind of hitting too hot  a temp) then if I continue to rev it at say 3,000rpm it will come on solid meaning the sensor is accurate.
 
At idle if I pull the plugs out cylnders 2, 3 and 4 are dark brown. Cylinder 1 is black. That is also the cylinder that hydraulically locked. So cylinder 1's injector is sticking open intermittently. Not all the time but sometimes its definitely dumping more fuel in then the other cylinders. If I rev the car to 4,000rpm for 60 seconds or so at idle, then pull the plugs out cylinders 2,3 and 4 are white, so running lean. Cylinder 1 spark plug is also white at the tip but more of the electrode is noticeably black sooner then all of the other cylinders. The whole end of the spark plugs are white on the other cylinders where as this one is a quarter white.
 
The car wont rev past 6,500rpm without having the spark cut which will be the ECU picking up Knocking I'm fairly sure because of the lean condition.
 
Is this what you have seen with other cars? Do you definitely reckon its the ECU that's causing this problem?
I also have the traction control fault code 47 coming on but could be because I have a fuse for traction control in the fuse box but no second butterfly for traction control. I have never seen this fault code registered by the ECU before.
What I was thinking is injector one is sticking open intermittently and maybe I'm getting low fuel pressure aswell because of a blocked filter or something?
I don't have a fuel pressure tester or noid lights but if the ECU was telling the injector to stay open all the time, the plug shouldn't go white unless there isn't enough fuel being able to be supplied right?
Or the other thing is the ECU is just going crazy and not increasing the injector pulse when lean but then also picking up the lean condition?
 
 
 
 
 
 
 

Bump.
Road and Track what were the cases you saw where the ECU was gone? What was happening?

Okay update on this. Gave my ECU off to be tested by one of the biggest ECU places in Melbourne. They just called up saying it is 100% fine. They can not fault it on the test bench its perfect.......
I've checked the TPS they is reading perfect. The only thing left is the MAP sensor to test I think....
The O2 sensor does not control anything at 2000-4000revs or under high load right, its only used for closed loop?

Yep just for closed loop.
Do you have the correct map sensor fitted? Should have a purple coloured sticker if gen3 turbo Mr2.
You still not tried a stock ecu which is known to be good?

Yeah will be the correct MAP sensor, its a factory GEN 3 GTS. Was running perfect till just after the last track event.
I've already checked the TPS and that sensors perfect, so now I have to check fuel pressure and MAP sensor.
 
The ECU was bench tested, so they run it through all the parameters and its 100% fine. On the bench they can check everything, feed it whatever sensor inputs so its definitely not the ECU. Cost me $132 to have it tested, took them 2hours. They do most of the ECU repairs in the country. They heat it up, cool it down, all fine.
 
I know injector 1 is dodgy so waiting for another set to arrive so I can start playing again with that sorted.

who is this ecu company?

Logicar

Alright update on all these issues. First off worked out why the car is rev limiting to 6,500rpm or there abouts. Basically there are a lot of people posting rubbish about which igniters are compatible with which cars. Turns out the one I got that a lot of people have listed on forums as being compatible with GEN 3 MR2's isn't right. It will rev limit the car to 6,500rpm. Ordered in a new igniter module, when that comes in hopefully it will solve that issue. The other issue was injector 1 is leaking, so still waiting on a new set of injectors to arrive.
the last possible cause is that the MAP sensor is faulty. It's reading a constant 0.20v even if I blow in the tube as hard as I can. Will see how it all pans out once I fit another new igniter and change the injector. Not far off from being sorted now...
 

If your map sensor does not change output according to specs with vac/pressure (you can use a syringe to simulate both ) then it is definitely faulty. I would sort that out first as its an obvious issue.

Cheers

The leaking injector is a definate and the igniter module is another definate issue. Once I swap those over I'll see how everythings running. If its lean I'll know I need a new map sensor. Just a bit odd that everythings happening all at once. When I plugged the old ignitor module in the car runs very rich before it shuts down. Basically the circuits in it are screwed. The problem with using a syringe or even blowing in the tube is I can't tell how much pressure I'm putting in the tube.....really need a special tool as listed int he BGB for it but regardless I'd expect to see a change in voltage just by blowing in it, so I reckon its faulty too. The igniter module really threw me though as soooo many people have listed it as compatible which it totally isn't. Will just see once I swap in a few of the new parts when they arrive. Not far off being back on the track which is a relief.