Fast idle

[Winston]

My 87 with 2F has been idling fast recently.
Typically it idles appropriately at about 650 rpms when I first crank her up and get going. But as it warms up and I come to stops, it's idling closer to 1000.

I obviously haven't changed anything - the underhood inspection looks ok.
Its a stock 2F - 90K miles.
And ideas? And before everyone jumps in with the carb rebuild - which I would love to do - this is my only vehicle so I just can't do that right now.

Thanks

 

[cfdlighthouse]

Basics first

check all your vacum hoses for cracks and that they are attached to the approriate places

check to make sure you fast idle circuit on the choke is not engauging or not disenguaging

make sure your lean idle mixture is set correctly

then you curb idle speed

then verify correct timing


that way you have a good basline setup. you may find something maybe nothing. but if those things are good it gives you a launch pad to move forward and best thing is unless you have to replace a vacum line the only cost is time.

 

[Winston]

uh,
besides checking the hoses, how do you do the rest of that stuff?

Is it all outlined in the manuals? I have 'em all.

 

[Ducks]

Mine does the same thing. Try just lifting up on the gas pedal with your foot when you are idling. That usually brings mine down to ~700 or so.

 

[NocalFJ60]

You have the A/C on while it is at idling high at 1000?

 

[Winston]

No - not using the A/C yet though I did turn it on the other day to see if it would affect it and it didn't.

I had the A/C serviced and the carb "adjusted" 1 year ago and haven't had any issues till now.

 

[NocalFJ60]

I would pull the vacuum on the diaphram for the AC idle up and make sure it is not stuck open. Could have a problem with a board or the switching valve. It should effect the idle but if it is already at 1000 then maybe it is not doing anything at this point.

Also like Ducks said about the pedal.

 

[cfdlighthouse]

uh,
besides checking the hoses, how do you do the rest of that stuff?

Is it all outlined in the manuals? I have 'em all.

manuals will give you all the info, you can search here on mud too...

easy stuff.

timing-requires a timing light and removal of the timing cover on the bellhousing on the passenger side of the motor. haynes manual has a good picture of it.

lean idle mixture and the others are described well in both the manuals on on here if you search carburetors adjsutments

those things are all good base setups to have, but the guys who have had similar issues to you seem to be pinpointing potential specific causes and i would follow those leads and get back to your baselines after you solve your primary high idle issue.

 

[FJ40Jim]

Maybe turn down the idle speed screw?