I just got my car running again today,and when the engine is cold it runs perfect,revs fine,doesnt sputter,miss idle funny or anything. Then once it starts getting warmed up it acts like the timing is way off and wont stay running. Its a 1993 honda civic lx with a mini me,only code is 41(oxygen sensor). This is really killing me and i cant figure it out,any ideas?

 

I'm not going to be much help here, but the ECU runs in open loop (base map) when the engine is cold. It would seem once the engine nears operating temperature and the ECU looks for sensor inputs, one or more sensors or wiring issues is causing the shut down condition.

BTW, the O2 sensor is only a messenger. It's very likely the run condition is causing the O2 to code, and not necessarily because the O2 sensor is bad.

 

Yes i know,but the wiring is perfectly fine,it didnt do this on my old motor,im thinking its the ecu.Once its warmed up it starts throwing random codes.

As for the o2 its for the secondary,which i do not have at all.

 

what random codes

 

Could be your ignition coil.

As the motor warms up, the coil could be building resistance and causing what it seems like a misfire/rough idle.


Did you use your old dizzy?

 

OK just bought a new oem reman. dizzy,car now runs good both when warm and cold.
However,now when it is warm and im driving,if i take my foot off the gas it dies. It will not hold an idle when its warm at all,ill rev it,itll die,ill start it without holding the throttle,itll die.

Any ideas?

 

Hows your idle adjustment screw?

What about the iac? is it connected?

 

Idles set fine,and yes the eacv is connected and working,ive tried new everything.Iat,Eacv,Dizzy,02,injectors,map and tps sensor. All i can think is my stock fpr with a walbro 255lph.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jaredvabeach &raquo;</TD></TR><TR><TD CLASS="quote">Idles set fine,and yes the eacv is connected and working,ive tried new everything.Iat,Eacv,Dizzy,02,injectors,map and tps sensor. All i can think is my stock fpr with a walbro 255lph.</TD></TR></TABLE>

so running rich causes a no idle situation?

 

well,when it did this on my last motor, they were able to fix it when i got tuned by messing with my air/fuels. Also when it is warm every so often it will idle,however ill rev it and as it comes down the idle catches its self at about 300rpm,and slowly builds its way up to 900 rpm.

Btw i did remove the charchol canister,all that bs and the evaporative emissions purge control solenoid valve that was mounted on the intake manifold. Not sure if that could cause it but helps just so everyone knows.


Modified by jaredvabeach at 3:54 AM 4/16/2008