B20b engine problems..... Help!!

[thirsk66]

I have had this issue ever since I bought my jdm b20 engine.The issue being is when I try to run an obd1 ecu the engine runs normal until it reaches operating temperature, and the engine just dies immediately . I have two obd1 ecu's a pr4 and p75 which both run my b20b like crap. I have tried a new throttle body with new TPS, two distributors, three IACV's, and a new timing belt plus valves adjusted by Licensed Acura Mechanic and yet nothing will help me run an obd1 ecu properly. I have an obd2b crv ecu which runs my b20 well but the idle scares me since it will go to about 550rpm or even lower it feels like. I am running out of options here. I really don't know what else to do. I have looked up all the info I can on this website and have come up empty with ideas.

[Dc4LsTeG]

Cel?

[HondaPartsHero]

You didn't list the make/model of the car.

[thirsk66]

Originally Posted by HondaPartsHero

You didn't list the make/model of the car.

Sorry no cel's on right now and my car is a 99 civic ex. I hope that helps. Also I have had some talks with people who think my timing is off but ill check it to see if it is or not, which I dont think it is since the Acura mechanic did it for me. Oh and to clear things up I did get the new throttle body from an integra Ls, so there isnt an FITV on it.

[HondaPartsHero]

What brand adapter harness are you using?

[thirsk66]

Originally Posted by HondaPartsHero

What brand adapter harness are you using?

the conversion harness is made by Yonaka. I got it for free from the shop I worked at. should i be looking to get a new one to test?

[thirsk66]

bump need more ideas/answers

[RonJ@HT]

Does unplugging the O2 sensor prevent the problem?

[thirsk66]

I have no idea I have not tried that yet, so I will try it and see what happens. The p75 ecu runs my car smoothly but the pr4 makes the idle surge a bit, but both make the car die as soon as operating temp is reached

[92lxsleeper]

use the obd2 ecu. the low idle is normal at first, you need to let it "learn the idle"

so drive the car long enough to bring it up to temp (fans have cycled atleast twice)

then park it, turn off ALL ACCESSORIES! then turn it off.

immediatly turn it back on, and do not touch the pedal or turn anything on for 15 minutes. after 15 minutes of idling, turn it back off, and you are all set

if that doesn't fix it, then you may need to manually adjust the idle up.

[thirsk66]

I do use the obd2b ecu and it works pretty well, and I have always used it since I got it a year ago. I just hate how low the idle goes and I will try what you told me to do and see what happens with it, and see if it learns the idle.
Also I tried unlplugging the o2 sensor and no luck it doesnt affect anything, the c ar still dies, so im thinking I will just have to not run an obd1 ecu ever. Just mad that I spent over $60 to get an obd1 ecu and it doesnt work for me in my favor.

[thirsk66]

I ordered another ecu conversion harness so lets see if that works in my favor this time around if not Im gonna have to blame my timing belt, or something that has to do with my timing, My b20 just doesnt have power like it should so it has to be timing related