'96 Civic Idle fluctuation when cold.
 

'96 Civic DX coupe D16Y7 engine.

When started cold the idle fluctuates from fast (what seems a normal fast
idle) to slow (almost stalling.) It straightens out after a minute or so
and then idles fine.

I removed the throttle body and gave it a thorough cleaning with tb cleaner.
I also removed the Idle Air Control valve from the tb and cleaned it.
Although the car ran slightly better, the idle problem is still there.

I'm suspecting a faulty Idle Air Control valve but I wanted proof before I
plunk down $150 for the parts. So...I followed the procedure in the service
manual to jump the service connector and watch for codes blinked through the
check engine light. Nothing! When the service connector is jumped the check
engine light stays on solid - does this mean there are no codes being thrown
or does it mean something else?

I also want to check for vacuum leaks. Anyone have any tricks to share on
this.

Thanks in advance for replies.

FartSmeller wrote:
> '96 Civic DX coupe D16Y7 engine.
>
> When started cold the idle fluctuates from fast (what seems a normal fast
> idle) to slow (almost stalling.) It straightens out after a minute or so
> and then idles fine.
>
> I removed the throttle body and gave it a thorough cleaning with tb cleaner.
> I also removed the Idle Air Control valve from the tb and cleaned it.
> Although the car ran slightly better, the idle problem is still there.
>
> I'm suspecting a faulty Idle Air Control valve but I wanted proof before I
> plunk down $150 for the parts. So...I followed the procedure in the service
> manual to jump the service connector and watch for codes blinked through the
> check engine light. Nothing! When the service connector is jumped the check
> engine light stays on solid - does this mean there are no codes being thrown
> or does it mean something else?
>
> I also want to check for vacuum leaks. Anyone have any tricks to share on
> this.
>
> Thanks in advance for replies.
> ===================

First thing to verify is coolant level in rad and reservoir, then remove
air at the bleeder, if so equipped.

Knowing the mileage helps narrow the clues too.

'Curly'

"motsco_ _" <"motsco_ > wrote in message
...
> FartSmeller wrote:
>> '96 Civic DX coupe D16Y7 engine.
>>
>> When started cold the idle fluctuates from fast (what seems a normal fast
>> idle) to slow (almost stalling.) It straightens out after a minute or so
>> and then idles fine.
>>
>> I removed the throttle body and gave it a thorough cleaning with tb
>> cleaner. I also removed the Idle Air Control valve from the tb and
>> cleaned it. Although the car ran slightly better, the idle problem is
>> still there.
>>
>> I'm suspecting a faulty Idle Air Control valve but I wanted proof before
>> I plunk down $150 for the parts. So...I followed the procedure in the
>> service manual to jump the service connector and watch for codes blinked
>> through the check engine light. Nothing! When the service connector is
>> jumped the check engine light stays on solid - does this mean there are
>> no codes being thrown or does it mean something else?
>>
>> I also want to check for vacuum leaks. Anyone have any tricks to share
>> on this.
>>
>> Thanks in advance for replies.
>> ===================
>
> First thing to verify is coolant level in rad and reservoir, then remove
> air at the bleeder, if so equipped.
>
> Knowing the mileage helps narrow the clues too.
>
> 'Curly'
>
Wow,

Thanks for the quick response and helpful tip about the coolant. I would
have never thought to check that. When I took the IAC off the throttle body
there was coolant present but, I know, things are much different when the
car is running. I'll check the level tomorrow.

Also, the car has about 180,000 miles on it.