Hey, My name is Logan and I bought a 2006 G35x Sedan Automatic Transmission about a year ago and it had 160k when I bought it. Now It had 180k on the old motor ( blown up ) and I installed a new motor inside of it. The "New" motor is a good known working motor too. I completed the swap and now the car has rough idle and it backfires when opening throttle. I added a stillen Grounding kit, replaced both cam, and the crank sensor and a few other small things like doing an ecu relearn and a throttlebody relearn. I bought all sensors from Nissan its self so they are "good" sensors. When I scanned the car it pops a crank sensor code and a c1130 ( engine 1 fuel cut system fault ) and I have bought 2 crank sensors for this car and neither of them change a thing on how it acts. The weird thing is that first crank of the day it will rough idle in park, I will shift it to reverse and it will steady its idle out and then from there I can shift into any gear and it will hold idle and it wont give me any codes and will run perfect but when I press the gas the car will backfire and start idling rough until I let off the gas. Ive been working on this for about 3 weeks now and it is stumping me, I should also note the car ran before the swap, If anyone has had anything similar to this happen to them please help. I should also note the car ran before the swap,

 

I should also say, since the car IS able to idle, coil packs, spark plugs, and injectors should be okay. I know ive said this before, but it is alaways first crank of the day where it will start rough, i will throw it in reverse and it will steady its self out in reverse. I basically just moved components from the old motor to the new motor.

 

Did you keep the existing cam sensor, crank sensor, throttle body, etc from the existing motor?

Did you perform the throttle closed postition recalibration, APP relearn, and the idle air recalibration?

Did you have the flex plate removed from the donor engine? If you swapped from your existing engine did you verify the alignment dowel was in the correct position?

 

C1130 is the ABS/VDC computer saying it's not receiving one of the engine signals.

Personally I would swap over ALL the electronics, injectors, coil packs, everything from the donor motor since you know they were all functional.

Are you sure you didn't get the coil pack harnesses mixed up? It's easy to do.

 

Check out this post to verify the correct harness order based on wire color.

https://g35driver.com/forums/g35-sed...ml#post7207226