just swapped in a B16a in my 2000 DX.... when i turn the key nothing, but if i jump the starter it fires right up...

things i've tried:
DX ecu
JDM P2t ECU
Ex harness
Dx harness

all yeild the same result, won't start with the key... i'm about to wire up a push button start and call it a day...

 

you've obviously missed a wire in the wiring conversion in the engine harness, probably the starter solinoid wire.
what have you checked as far as wiring. I hope you didn't just jump the starter and then make this post.

 

oh, and i've checked the singal wire, it recieves no signal. checked the IG1 fuse under the hood, it looks good. The only thing i haven't checked is the starter relay, but i don't know how to tell if that is good.

 

both ecu's are OBD2b there is no wiring converstion. and what do you mean jump the starter and make this post?

 

is the engine grounded good? I had this problem a while ago.

 

well i double checked all the grounds, and for the hell of it i hooked up a set of jumper cables to the engine and grounded it on the chassis
i know i'm missing at least one of the grounds, the one from the valve cover to the chassis. was there one from the intake mani? i don't know where all the grounds are on the B16a...

i have the thermostat ground connected and the tranny ground.

but if it was a ground issue why would it start if when i jump it from the battery?

 

and just for further testing i took my DX starter grounded the housing, attached the signal wire and the battery cable wire and tried to spin that starter.... still nothing

 

check all your wiring