okay so as ive stated before my 2002 rsx type s had a previous owner and he blew the engine up in it and replaced it with the k20a3. He used the 6speed tranny and prb ecu and wiring harness. So i finally got all my paint work done had some money still to spend so bought a k20z1 from an 06 typeS and swapped it over the weekend. Everything went just fine, used my a2 wiring harness, prb ecu, and 6speed tranny. Hooked a matco scanner to it just so i could moniter o2 sensors, timing, etc. Cranked it up and it ran just as smooth as a new car, let it idle for awhile to get primed up, reved on it a lil sounded good. Checked for leakes and all the double check stuff. Took it for a test drive and everything checked out vtec pulled pretty hard with the new long tube header...i already have a skunk2 exhaust, cai, and nology hotwires, with a stage2 clutch an lightweight fly. Anyway get back to the shop and go to unplug the matco scanner and it DIES. WTF, so i try to crank it without the scanner and it just trys to turnover but it wont and my rpm needle bounces while trying to crank. Hook the scanner back up and it cranks fine, rev on it, everything is fine...unplug the scanner dies again.. Does anyone know whats could be going on. i tried reseting the ecu and still nothing it will not run unless the scanner is hooked up....SOMEONE PLEASE HELP.....Could it be the immobilzer..I wouldnt think it would be that being that i used my old wiring harness.

 

leave the scanner plugged in o_0......sorry i got nothhing bump to the top! someone help him out

 

you didn't swap ECU's right? So then the immobilizer hasn't changed.

 

k so it turned out that the main ground wasn't tightened down and the scanner was completing the circuit.... so we I tightened it back down an everything is fine we successfully swapped a k20z1 into a 02 rsx without swapping any sensors and we pulled it out the top hahaha

 

How was your car running when it had the k20a3?
I blew my motor, and I think I am about to do what your previous owner did.