Hey guys,

I have a 1994 Honda Civic DX with manual transmission. The problem i'm experiencing is that the car start up and idle perfectly, but 10 minutes after it warms up, it throws an engine light and the idle starts going up and down.

Anyone know what this might be? I haven't pulled the engine code yet, but i'm hoping to get some insight to help me diagnose this issue.

Thanks!

 

ttt any input?

 

It could be your IACV. It registers the coolant temp and conrols the airflow. This sits on the throttle body and the coolant flows through it. It's possible that it's gone bad. Post the engine code on here when you pull it off, it always helps when you have the CEL code.

 

Pulled a code 40 -> does this even exist? I can't find out what it means anywhere.

 

Get it from a haynes manual or something. I'll look it up later on today and post what it is.

 

i think its your iacv. it either needs replaced or cleaned. my eg8 lx gave me the same problem (minus the CEL).
check the date on your fuel filter too. that might need replaced.

after clean the iavc and replacing the fuel filter my car runs great now.

 

IAC IAC IAC, lol.
how many of these post's can there possibly be?

^^X2, CLean it out, if that doesnt solve it, replace it.

 

yeah same **** happened to me, my idle drops to 250 rpms at times, check engine light went on and surely enough it was my fuel filter. i replaced it and it still idles low, so im gonna clean the IACV like everyone says, but im not sure how to go about doing that....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Weapon_R &raquo;</TD></TR><TR><TD CLASS="quote">Pulled a code 40 -&gt; does this even exist? I can't find out what it means anywhere.

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I looked and there is no code 40 from what I could find. The closest is code P0400 which you could have mixed up and thought it was 40? This code indiactes a exhaust gas recirculation flow malfunction. The other code close to it is P0440 evaporative emmission control system malfunction.

 

so its 4 long lights? and not 4 short lights?

 

haha since i'm only getting 4 lights, and this being my first honda in quite some time, I don't really know how to differentiate between long and short pauses.

Let's say its 4 short ones, which would be the Crank Position Sensor. Would my problems be associated with this issue? If so, what needs replacing?

As for the IACV recommendations, that is definately a possibility but it doesn't explain the CEL code nor does it expalin the slight bog when I accelerate.

 

There also could be some type of vaccum leak somewhere, possibly a bad throttle body gasket even. It really could be a number of things. I would look at the codes more closely and see what articles that you can find on those codes. Usually service technicians post up what can cause those codes.

 

i think am having the same problem can someone post a picture of these part dont know which one it is thanks