Thread: lowport problems

Hey guys, so i swapped in a Uk 10:1 lowport motor into my 91 nx2k. the problem(s) that im having are: the car turns on but has a low choppy idle sumtimes at 500, almost sounds cammed, when i would try to floor it, it kinda bogs and stalls especially when the rpm's hit 4k for sum reason, it just wont crank open. I am not running my egr, or cat, but i was running it on my old motor. My check engine light hasnt come on r anything so its not throwing a code. Pretty much stomped, any opinions or info that u mite have will b greately appreciated thnx.

Did you test the MAF? Is it properly grounded? Also did you try to bump the idle. UK motor has bigger cams so it will act more lopey if the idle is a bit low almost like S3s.

vac leak?

Good point Will. I have on two separate occasions forgotten to attach the idle air bypass hose after a swap. It goes from the intake hose to the intake manifold. That was similar to your description too.

sounds like a skipped tooth of the chain.worth checking.