Ok, so I bought a 91 240sx shell. I have an extra KA24DE from a 96 or 97 240sx. The engine was run with an automatic tranny on it. Now here is my question. I will be using a 5 speed tranny from an 89 240sx with the KA24DE. So, does it matter which ecu I use? The obd1 was used in the 91 240sx, but obd2 was used in the 95-98 240sx's. Since I have an engine from a 96, but an using a 89 5 speed transmission, which ecu do I need?? If you think of it, pretty much, the kade's are all the same. and what parts of the ecu harness plug into the engine? the fuel injectors and the o2 sensor?!

I really need to know what ecu to use?

Everything is measured electronically in a ob2 I do believe.don't take my word for it.

I don't think that the transmission effects the ECU at all. OBD2 just has a whole bunch of on board diagnostic stuff that the OBD1 lacks. It NJ OBD2 cars are hooked up to a machine for emissions testing when they go in to inspection. Personally if I were you I'd probably use the s14 ECU just to be safe if it a plugs in correctly but then again It may not matter.

Thats what im thinking? because I am putting it in a s13 chassis? I still want to know what people think though.

Not to ask a completely stupid question but what are the actual differences between the two. I have a friend with a Rabbit that converted back to OBD1 but whats the advantage

the trans has nothing to do with the ECU at all. like someone mentioned already the OBDII is just On Board Diagnostics version 2 that is all. it will tell you how your emissions are running and pretty much everything else with the motor. you can not look up trans code from OBDII that is done at the dealer unless you know what code is what.

the OBDI stopped in 95 around august or September so its kinda hit and miss if you have OBDI or II on a 95. here in NC if you have a 95 or older you don't have to get emissions testing no matter what year the motor is from, they just go off you chassis

don't know if that helped but it my 2 cents

thank you, that helped me a bit. I was just talking to one of my friends who has had like 6 240's, and he said that all you need to do is swap out the intake mainifolds. THe mainifolds with obd2 have more sensors and what not. I think that pretty much answers my question. Thank you for all of your help

s14tan wrote:Everything is measured electronically in a ob2 I do believe.don't take my word for it.

Yeah I was gonna say the same... Lemme look it up and I'll get back to ya...

I'm swapping my 91 obd1 ka out for a 98 obd2 ka and it use to have an auto tranny. I hooked up the 98 ka to the 91 tranny and used the ecu, wiring harness, and distributer from the 91 on the 98. I'm almost finished. should be done early febuary. There is no reason it shouldn't work. I have friends who are nissan technicians who told me to do it like that and that it should work. wish me luck.