i have a 00 b20 in a 98 ek. i was running obd2 LS and it was idling fine. I decided to convert it to obd1 with a 95 LS ecu. On cold starts, it revs"up and down" until it warms up, it idles fine at 700rpmish. how can I fix this problem? how can going obd1 from obd2 that was idling fine go wrong from the conversion?

I have no CEL, does anybody know what can be the problem? Bad 95 ecu?

 

I have the same problem. After getting my Hondata installed with a modified P06-->P28 OBD1 ecu, the car always idles high (sometimes very high) and revs up and down over and over, then finally settles down above 1000 rpms. I also have starting problems where the car will barely start and then idle rough at low rpms, then climb. I have no vacuum leaks either. I just installed a brand new IAC valve. My car is a '99 Si and doesn't have a fast idle valve. If you find anything out, post it here and I'll do the same if I figure it out.

 

yea man, switching to obd1 should've been just plug n' play! is there any ecu conversion/idling guru's around??

 

I have a 98 ctr motor in my 97 ek. I installed it and on a cold start it would not stay on without me holding the gas pedal down till it warmed up. Then it would idle up and down. if I would drive it and stop at a light it would idle up and down until I pull the gas pedal out with my foot to make it stop doing it. Then it would idle fine until I had to stop again. I have a convertion harness obd2 ot obd1 with a p28 ecu. Let me know if you find anyhing out.

 

Your problem is similar but seems a little more complicated than mine. What would not stay on, the engine? It should only rev "up and down" until the engine is fully warm.

Could it be a vaccum leak that the obd2 ecu doesn't detects but the obd1 does?

I'm using a '97 obd2 intake manifold and TB, but i've heard on obd1 TB's, it uses the "fast idle valve" in conjunction with the IACV to idle correctly on cold start-ups. Is this true on 94-95 DC LS that it utilize the fast idle control valve?

As we know the more advanced obd2 ecu only needs the IACV to idles steadily.

 

Weiiiiird, I have the same exact thing happen with my 97 gsr after I installed a hondata s100

 

yea..i think all of us who has this problem is lacking the mechanically operated fast idle thermal valve that obd1 ecu works with...hmm..that's the problem, how do you add a FITV?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kinvid &raquo;</TD></TR><TR><TD CLASS="quote">yea..i think all of us who has this problem is lacking the mechanically operated fast idle thermal valve that obd1 ecu works with...hmm..that's the problem, how do you add a FITV? </TD></TR></TABLE>

use and obd1 style throttle body.

 

i fixed it...seems like i overlook the ecu serial number and assume i bought a manual ecu. it turns out i was sold an automatci ecu! lucky i knew how to convert to manual and now the problem is fixed. i don't get the cold idling problem...

 

That is cool that you fixed your problem. Mine is still broke but it can't be the ecu because the car we pulled it out of was working just fine.