90 Civic DX. Lately this car has had an irratic idle. Scenario: after driving for a while and pulling up to a stop light the car will either idle high and hold there or it will idle up and down. Sometimes you can stop this by giving it gas then letting go. This will sometimes drop the idle to normal.

Now can anybody tell me from experience if a bad o2 sensor could be the problem. Cause lately in the mornings I've been getting a CEL code 1 which we all know as the notorious o2 sensor.

Another possible culprit that i was thinking about, was the cooling system (i.e. water pump) since I'm not sure when the previous owner last replaced this and it seems to act up only when it's reached normal operating temp. But could anybody shed some light on my situation. All help greatly appreciated.


Modified by CrxSi707 at 5:07 PM 5/1/2003

 

bump.... com'on folks I thought this was Honda Tech, where did all the tech help go?

 

O2 sensors control the air/fuel mixture. Don't see why it would give you a crappy idle. Try and check your timing, that will make your car run crappy, and also see if your vacuum hoses are in good shape as a leak in this will mess up your car.

 

The EACV can also cause idle problems, you might wanna take a look at that too.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRzex &raquo;</TD></TR><TR><TD CLASS="quote">The EACV can also cause idle problems, you might wanna take a look at that too.</TD></TR></TABLE>

That is what I was thinking. EACV and possibly the O2 sensor. Is your ECU Throughing any codes?

 

are you low on coolant?

my car was almost out once and the idle went crazy,

your waterpump could be failing as well.

 

My ECU is throwing a Code 1, only. I am gonna replace the water pump and t-belt. I have an extra 88 CRX si o2 sensor, that I'm going to swap in. As for this EACV I assume it's on the intake mani somewhere... anybody got a pic or diagram of it? Do you know how much a new one costs? Thanks for your input guys.

 

Oh and the car runs fine... no stuttering or missing and it's got good power (for a DX) it only acts up when the car is at idle. it's my daily driver so I need to get it fixed. I hate driving my CRX everyday.

 

if it's fine when ya first start it, then irregular after it warms up it's a seal on the evac that won't let the valve close back up when warmed up.

Another possibility might be vacuum lines. Don't know much bout that cel code.

 

Anybody got a pic of the EACV? Thanks again.