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Old February 19th 08, 08:42 PM posted to rec.autos.makers.honda
Paul Jr
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Posts: 6
Default 1990 Honda Accord Idle fluctuation

On Feb 10, 2:40 am, Tegger > wrote:
> Paul Jr > wrote :
>
>
>
> > On Jan 3, 7:04 pm, Tegger > wrote:

>
> >> Another air-related suggestion: When the car is warm and the idle is
> >> fluctuating, remove the air cleaner pipe to the throttle body. Can
> >> you progressively cover the throttle body with your hand to the point
> >> where the idle settles down?

>
> >> What happens if you unplug the EACV? That's the idle air control
> >> valve behind the throttle body. Sometimes a stuck-open EACV causes
> >> fluctuating idle.

>
> >> And did you check the coolant in the rad, not the reservoir?

>
> > Yes, if I can cover the throttle body enough to set the idle down.

>
> Bingo. You have a major air leak somewhere.
>
>
>
> > I unplugged the EACV and the idle jumped up to a fast idle and the
> > check engine light came on.

>
> It is normal and expected that the CEL would illuminate when the EACV is
> unplugged.
>
> > I had to restart the car before the idle
> > would settle down again (actually fluctuate again).

>
> So the idle fluctuates even though the EACV is unplugged?
>
> Hmmm.
>
>
>
> > Does this tell you anything? Is the EACV the culprit?

>
> You have large amounts of unwanted air entering the system.
>
> Before anything else is done, you need to check each and every one of your
> many vacuum hoses, including the ones inside the EGR control box on the
> firewall.
>
> You also have an Air Boost Valve. It is at the opposite end of the intake
> plenum from the throttle body. With the engine idle fluctuating, disconnect
> the Air Boost Valve's vacuum hose and plug the port in the valve with your
> finger. If no settling of the idle, this part is OK.
>
> Chek all the bolts/nuts that hold on the intake manifold and other intake
> parts. Loose intake parts will leak vast amounts of air.
>
>
>
> > Yes, I check the coolant levels and "burped" it also. I am very
> > confident that there isn't any air in the coolant system.

>
> If the coolant is right up against the bottom of the rad cap, then the
> level is fine.
>
> Your focus now is to find that air leak.
>
> If you are 110% certain you have eliminated the possibility of any air
> leaks, then -- and only then -- we try readjusting the idle speed screw.
>
> What are these three digits of your VIN (represented here by x's? JHMCBxxx
> (No personal information is in those three digits).
>
> --
> Tegger
>
> The UnofficialHonda/Acura FAQwww.tegger.com/hondafaq/


Sorry, I didn't write that very clear. When I unplug the EACV that
idle jumps up to about 2000 RPMs and stays there. I was trying to say
that if I plug the EACV back in, the idle wouldn't calm down and
fluctuate again until I restarted the car.

So is it my EACV that is the problem or an air leak somewhere?

My VIN is HGCB714

I really appreciate your help,
-Paul
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