IS a JDM tll diferent than the regular tll ECU???

 

Yes, but the the only time it matters is with the S5 turbo ecus. The J-spec N374 often needs rechipping to work with US-spec cars. N370 is the US ecu equivalent.

 

well i have a JDM engine But the ECU is not. So i think thats my problem.

 

they may still work however....

 

I don't know what your problem is, but I can tell you that's not it. The complications I mentioned come from body wiring/electronics differences, the engines themselves and all sensors are nearly identical. The only real electrical differences between US and Japanese engines are emissions related and not important. Just about everyone with a S5 turbo swap uses the US-spec N370 ecu regardless of where the engine came from.

 

So what is the problem then? what symptoms ya got?

 

well these are the symptoms...
I start the car then drive it around the block fine in the second try the car starts to misfire no power. i turn it off and its fine again but same thing after couple seconds misfire again.......

 

How long until it starts to misfire? like ten minutes maybe, sometimes a lot sooner? Is this a s5 turbo? Are you getting check engine lights at all when it starts misfiring? sounds kinda like limp mode from your vague description....

 

I agree, sounds like the car is going into limp mode...I know often times it can be caused by a malfunctioning OMP, start by pulling the codes.

 

were do i do this and how???

 

OMP testing: S5 FSM section 2, pages D-16 to D-18.

 

Just go down to your local auto store..I think they all pull codes for free now (in hopes to sell you stuff) see if you get a OMP code....start there.

 

I doubt any of them know how to even pull the codes on a non-OBD car.

 

with the jspec harness can u use the n370 and will everything work jsut fine?

 

If its an S5 it is very easy.

http://www.fc3spro.com/TECH/HOWTO/ER...KI/kerror.html

 

Yup. It's most likely OMP. I do have one for sale if yours is indeed bad. Electric omp, n/a and TII's are the same.