ECU problems??? Help pls

Where abouts are you located? Sydney?

from reading your post it seems that your problems started after the engine swap. if that is the case then the mechanic who swapped the engine should rectify the issue, easier said than done though.
 
I dont own a spyder but they are known to have issues with the gearbox, can you clarify what type you have i.e. sequential or manual?
 
if you think its a faulty ecu, maybe you can ask another spyder owner (there are a few on the forum) to plug their ECU into your car to see if that makes any difference. this should only take half an hour or so

Well I own a couple of these but dont know much about how they work along with everybody else in this world. I have a ECU here that you can try as I just pulled my motor out and will not be using it again. These problems are usually caused by the TCU though which is the computer to control the SMT. I have that you can try also but at thge moment it is in my other car 15 mins up the road but can be pulled out in 30 seconds. If you have taken it to these different mechanics they should have found the codes that it was throwing?
If you go onto Spyderchat and get onto Cap Weir he could give you answers better than Anybody on what the problem is and how to fix it. From what I have seen the TCU isd always blamed but it is usually just a small part that is at fault and an easy repair once you know what it is. You are welcome to try my ECU and TCU to see where it gets you? I am in Penrith.

For people on this forum who are curious to know what the result was, and to save others from this absolute headache... it is the ECU- it needs to be replaced.
Once the ECU has been replaced, if it still doesnt fix the problem, then the SMT itself also needs to be replaced. Then problem fixed!

I was told about this mechanic in Leppington who specialises in SMT's and MR2's in general.
He's dealt with this problem many times before, and knew exactly what i was going through with my MR2 before i could finish off my explanation. I also wasted $60 asking a toyota specialist online who told me the same thing AFTER i had already found this out by helpful people on this forum and that specialist mechanic.
The online specialist said that once i change the ECU, if its not fixed- to change the TCU, then finally the transmission assembly itself. This is what he wrote:
 
 
"Those particular MR2's had a slew of problems, especially the sequential transmission models. Before getting yourself too deep into this, I want you to weigh your options carefully. Because this repair could potentially cost you up to $7000.
 
Those had problems very regularly with computers. An updated ECU was released from Toyota to correct the computer problems. You also could have a problem with the transmission computer. These are also common for failure. And finally, you could have to replace the transmission assembly. There is a very real possibility that the only real fix for you would be to replace all 3 components, which can be extremely costly, very quickly. Unfortunately, due to the intermitancy of the issues, and the way Toyota has the system designed, you never really know exactly what the problem is until you replace one of the parts and see if it is fixed. Just be prepared, that after you replace the ECU, it may be fixed for a week, a month, or 6 months, and then it starts acting up again with one of the other 2 components I mentioned in a failed state. I have seen this happen many times.
 
If I had to take a stab in the dark, I would start by replacing the computer with a new one and see where it leaves you. Unfortunately, the only way to know is to replace it and see what happens"
 
 
Hope that helps someone else :)