im running a d16y8 with 2000 ex engine harness but its missing a o2 outlet on the harness so i got jumper harness and got a p28 ecu and converted to obd1 but the rpm was super low i think the usual should idle at 600-800 rpm but mines idle at 100-300, low enough that the car dies when its idling. i checked my throttle body and my ivac cleaned it all with berryman throttle cleaner. but the problem still happens idle is super low about 200 rpm. i tryed turning the screw on the throttle body and samething happens....low rpm. does anyone kno anything else i can do? is there a way to chip the p28 ecu and have it idle higher?

 

You used the OBD2b conversion harness and not the OBD2a, right?
Is the CEL on?

When you turn the idle adjustment screw you are suppose to run the engine until it is warmed up and turn it off, then unplug the IACV electrical connector before starting the engine, and then adjust the idle with the engine on. Then turn off and plug the IACV back in. You are aiming for like 400RPM I think whenever you adjust the idle. Plugging the IACV back in should make the computer then adjust that 400RPM to the proper RPM.

 

yea i got obd2b to obd1 harness and i did do all that


is there anything else i can do??

 

and no codes

 

i told you how to adjust the idle the right way.
it doesn't sound like you did it the right way.

 

i did i go to my dads friends shop got all those instruction off a program off his computer called michells or something and did everything and when i put my p2p ecu back the stock one for it rpm is fine but engine check

 

sounds to me like the P28 you got has something wrong with it.

 

its a p28 off a 95 civic ex manual with 132k on it

 

so?

 

jus throwin it out there im not only talking to u.....

 

i understand that... but it doesn't matter that it's off a 95 civic EX manual with so and so miles.

If it's a manual P28, it's a manual P28. nothing else to it.

 

ok then thanks for the info nice to know....

 

bump because i have the same problem, yet i have a P08 ECU (same as the P28, but rare and its JDM!)

 

anyonee.................?

 

jump the service connector, adjust idle screw, unplug the service connector.

if thats not fixing it... http://www.ef-honda.com/ben/Badidle.php

https://honda-tech.com/forums/honda-prelude-4/irratic-idle-problem-1029481/