I just swapped a B20 into my ek hatch(96) I've been running the cx ecu till last night when I got my OBD2 P75 ecu.

It plugged right in but then it won't start. I switched it back to the cx ecu and it started again.
what could the problem be?

thanks in advance

 

What noises does it make? Does it crank? Are you throwing cels?
more info.

 

it does crank. it sounds like its about to start.
i'm not sure if it's throwing cels

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lowRIDAH &raquo;</TD></TR><TR><TD CLASS="quote">it does crank. it sounds like its about to start.
i'm not sure if it's throwing cels</TD></TR></TABLE>

Do you know how to check?
https://honda-tech.com/zerothread?id=1171263

Then post your results.

 

Raise the fuel pressure.

 

My boy Japearl is prob right.. I have a b20 in my del sol with a P75... HAd similar issues... U need to up the fuel pressure because the P75 runs a A/R mixture that is too lean for the B20...give that a try hopefully it is ur problem because it is a simply fix... Keep turning the fuel. pressure up in small increments until it starts running good.... try starting off my running it pig rich and work ur way down until ur reading good A/R ratios.. Trust me u will know the difference by driving it if u have it to rich or to lean... it will sputter when u accelerate in some shape or form... to japearl for a legit answer to ur issue.. tell us all how ya made out... and good luck... believe me when i did my swap i had all kinds of air fuel issues... u will work them out my friend

 

o i forgot.. if what i described isnt ur issue... u sure u that u got a stock P75 ecu... cause if it is tuned or just base mapped for a different setup you will have all kinds of issues.. Try the fuel pressure first and if not i got a few other tricks up my sleeve of wut it may be... why dont u open up ur ecu and make sure its all stock...

 

i found out what it was.
when the engine was swapped in i told the guy I'll be using a harness and converting it to OBD1. therefore i needed to use an OBD1 p75.

i could only get my hands on an OBD2 ecu.
supposedly the obd2 p75 has a crank sensor that the obd1 doesn't.

i found an obd1 p75 and it finally started.
I'm running lean like you said though...it sputters a little bit.