So, I did the whole swap with on of my friends at his shop in two days. S5 NA to S5 JDM Tii. (full drivetrain swap)
Well, when we started the car, the engine vibrated really bad, and it didnt not sound like it was running smoth. My turbo air pump was bad, and the NA doesnt fit, so I was running the car w.o an air pump for now, and just one belt (no PS or AC). As the rpms increased the vibration went away to a point. The boost guage was reading -15 vacum, and if I reved it to 7.5krpm it would hit most 4psi of boost. After drive the car few miles and doing another oil change, we check the spark plugs and realized that the rear rotor was not igniting. It was getting fuel and spark. We checked the secondary injector, it would start to open arround 6krpm in neutral, and was the same case for the front secondary. The front primary would open all the time, but the rear primary was not opening. The spark plugs in the rear rotor was almost as brand new as they were when I put them in. With traces of oil and fuel. We though the wiring to the rear primary injector was bad, but then when the put the N350 ECU in from the N374 ECU, the car sounded good, andwas very smoth. The sad part was, this was at 4am, and we have already taken off the the intake manifold already, and when we put it back together we had some vacum leak we couldnt find, so the car would idel very high or it would just stop ideling and die off. So I cant tell you if the car would have run good with the N350 ECU. I would like to know what you guys(girls) think about this, and what ideas do you have? I will keep posting as we check more stuff and see what happens.

 

hey...welcome to the j-swap club! sounds like you are on track,make sure all your vaclines got hooked up,like the ones on the back of the throttle body.Did you keep your emmissions?if not maybe a block off plate isn't sealed right. At least the ecu seems to have solved your prob with not firing the rear rotor

 

No, I am keeping my emissions, but I don't have an air pump at the moment, so I have the rest hooked up, but no air pump or it's drive belt on the engine. I'm not sure how not having the air pump hooked up will affert the car... =( Anyways, why would the N374 ECU not fire the primary injectors on the rear rotor, but fire the secondary? (injector is good and wiring is good, and both tested).

Also has anyone tried to run a Tii with a N350 ECU? does it run good? or like crap?

 

How did you test that injector? If it is good, you might have a bad driver in the ECU for that injector. Also, the input for timing for injector control might be bad for the rear rotor. Just some direction to hopefully get you started on your troubleshooting. Good luck bro and keep us informed on your progress.

 

Seems like several people have had problems with the N374 not firing the injectors. I did the same thing, swapping out the N374 for the N351 and it run just fine i havent had any problems.

 

well I checked the injectors with a pulation checking "thingy", then I swaped the plug from the front primary to the rear primary, and then the rear rotor combusted, but the front one didnt. Then I put the plugs back on the right way on the primary injectors, installed the N351 and both rotors combusted. The only sad problem was that I did this after I created a big vacum leak somewhere which I will have to fix today or tomorrow. (i ordered new intake gaskets and waiting for them to come in). I will take a look at the N374 ECU, I really think your right and it is bad or something...

 

I was just wondering, can you run a S5 Tii with a N351 ECU? or will there be problems? Good luck with your swap bro.

 

Ok, so I found the vacum leak =). BUT since the extension from the intercooler piping to the BOV was messed up we removed the BOV from the equation so I only drove the car a low rpm (under 3000) since there was no place for the excess boost to go lol. It seems good, tho there was no load... it was snowing here, the idel was very rough... about 800rpm, but both rotors were combusting, spark plugs confirmed that this time (also, sometimes letting off the gas was rough). Still using the N351 ECU since the N374 seem to be bad. I will find out tomorrow how the car runs with the BOV installed. I'm still running only one belt on the drive pulley cuz I cant find a damn Tii air pump anywhere!!! =(

I was wondering, what happens with the input from the knock sensor and turbo duty solenoid if I'm using the N351 ECU? And also, does the NA ECU cut fuel over 8.7psi? would there be a need for the FCD to be hooked up?

 

is the ECU a JSPEC on a ASPEC harness? I've seen this happen a few times before. if you can find an N370 ASPEC ECU I bet it'll work fine.

good luck

 

I have hit 12 psi on the N351 w/ out any fuel cut but an N370 & FCD would probly be the safer way to go

 

I hade the same problem as you. Not running on the rear rotor.
Never got the Jspec ECU to work correctly so i went away with a standalone..

 

Yes I am using the Aspec NA harness. And I was thinking about trying to get a N370. I'll update later today after I fix my BOV problem and replace that part.

 

P.S. Also is there anything bad if your running just one belt on the drive pulley? (the alt. belt)
And, anyone know how the wiring goes for the 5th gear switch and reverse lights from the back plug coming out of the back of the tranny?

 

Ok, so I have my Bov installed with the leak fixed. Runing N351 ECU with Tii afm and pressure sensor. I seem to be pushing about 7psi of boost (not sure why its so low or if the guage is inacurate). I dont have the stock intake piping, and I have 2.5" downpipe with full straight exhaust (everything 2.5" and a racing high-flow cat). I was thinking maybe it would run 8-9 psi. The car seem to accelerate good, and decelerate good, but when you are trying to have SOME throttle and keep a certain speed, it runs like ****. The check engine comes on sometimes, and then you just let off the gas and it goes away. I think thats from the TPS not being adjusted properly. Also I do NOT have the air pump on my engine, but I am NOT removing emissions, so I'm just waiting for a replacement air pump shows up, so I just have the hose plugged off that goes into the air pump. Any ideas whats going on?

 

anyone?