I have an Accord exv6 98 auto, 115'000 km (or 72'000 miles).

I have a problem when I start the motor when it is slightly warm (5 to 10
minutes after having stopped the engine): Idle goes very low (around 200 to
300 rpm). It needs 2 minutes to go to normal idle (around 800 rpm).

It never happens when the motor is hot or cold.

Air filter is new.

Thanks for your help.

Alan

 

My '94 Civic behaves in a similar way: Start the car, and it idles high
as it is supposed to. Then as it warms up idle drops to ~400 RPM until
the engine is fully warm. At that point it idles at ~650 - 700 as it
should.

The car has been this way since new. Under warranty they took out and
cleaned the IAC (Idle Air control Valve) and it worked better for a
while. I have not found a solution, but a workaround is the leave the
headlights on until the engine is fully warm. The additional electrical
load causes the ECU to increase the idle just a tad.

If you find a solution, please post to group!

Alain A wrote:
>
> I have an Accord exv6 98 auto, 115'000 km (or 72'000 miles).
>
> I have a problem when I start the motor when it is slightly warm (5 to 10
> minutes after having stopped the engine): Idle goes very low (around 200 to
> 300 rpm). It needs 2 minutes to go to normal idle (around 800 rpm).
>
> It never happens when the motor is hot or cold.
>
> Air filter is new.
>
> Thanks for your help.
>
> Alan

 

There are multiple temp sensors on these cars. I'll bet that one of
them has a bad connection or is sending a false reading. Take a close
look at the ones on the block under the distributor. bob

Randolph wrote:
>
> My '94 Civic behaves in a similar way: Start the car, and it idles high
> as it is supposed to. Then as it warms up idle drops to ~400 RPM until
> the engine is fully warm. At that point it idles at ~650 - 700 as it
> should.
>
> The car has been this way since new. Under warranty they took out and
> cleaned the IAC (Idle Air control Valve) and it worked better for a
> while. I have not found a solution, but a workaround is the leave the
> headlights on until the engine is fully warm. The additional electrical
> load causes the ECU to increase the idle just a tad.
>
> If you find a solution, please post to group!
>
> Alain A wrote:
> >
> > I have an Accord exv6 98 auto, 115'000 km (or 72'000 miles).
> >
> > I have a problem when I start the motor when it is slightly warm (5 to 10
> > minutes after having stopped the engine): Idle goes very low (around 200 to
> > 300 rpm). It needs 2 minutes to go to normal idle (around 800 rpm).
> >
> > It never happens when the motor is hot or cold.
> >
> > Air filter is new.
> >
> > Thanks for your help.
> >
> > Alan

 

Alain A wrote:
>
> I have an Accord exv6 98 auto, 115'000 km (or 72'000 miles).
>
> I have a problem when I start the motor when it is slightly warm (5 to 10
> minutes after having stopped the engine): Idle goes very low (around 200 to
> 300 rpm). It needs 2 minutes to go to normal idle (around 800 rpm).
>
> It never happens when the motor is hot or cold.
>
> Air filter is new.
>
> Thanks for your help.
>
> Alan

=================

If your radiator _reservoir_ isn't full to the line (I mean to say
empty), the air in the system will fool the temp sensors until the
thermostat opens.

On a different note: Topping up the gas tank can also cause problems
because the evap canister can throw the idle off until it gets 'dried
out' again. Never top up a Honda, unless it says so in the manual.

'Curly'

=================

 

It's strange because my car does not behave this way. It has no problem
during warm up. It has problems only if it is started slightly warm.

> My '94 Civic behaves in a similar way: Start the car, and it idles high
> as it is supposed to. Then as it warms up idle drops to ~400 RPM until
> the engine is fully warm. At that point it idles at ~650 - 700 as it
> should.

 

Seems like it is not related to one of those 2 ideas. Thanks a lot Curly
anyway.


> If your radiator _reservoir_ isn't full to the line (I mean to say
> empty), the air in the system will fool the temp sensors until the
> thermostat opens.
>
> On a different note: Topping up the gas tank can also cause problems
> because the evap canister can throw the idle off until it gets 'dried
> out' again. Never top up a Honda, unless it says so in the manual.
>
> 'Curly'
>
> =================