89 accord won't idle (carburated)

[dh89lx]

Hello,

I have an 89 accord LX, carb, auto which all of a sudden will not idle. It runs fine above idle but as soon as you let the rpms get down around 1000 or 1100, it dies. It dies very predictably every time. As long as you hold it above idle, it starts back up and runs fine. The other day I had to use the car and after about 30 minutes of operation, it reverted back to normal and idled fine. The next morning, won't idle. The first time it happened it was at operating temp and had been running for quite a while. My first thought was the primary slow mixture cut off solenoid valve. I also started getting excessive noise out of the air suction valve at idle a few days before this problem started so I guess I'm suspicious of that also.

A little background: I rebuilt the carb 2 years ago with complete success (even a blind squirrel gets a nut once in a while) and disabled the choke (wired open) a year ago after the heater failed. That was supposed to be temporary but living in southern Arizona, I discovered that I never needed the choke anyway. It's pretty low mileage for a honda (190,000 miles) too.

I really need to start driving this thing again so any advice would be greatly appreciated.

[A20A1]

If you're choke is working and the idle is dying out it could be a vacuum leak, from a gasket or PCV valve or vacuum line or faulty solenoid or thermovalve.

If you have no choke you might just want to use a manual setup for the choke or replace the faulty choke unit.

I forget if leaving the choke in the full open position had an effect on the fast idle cam or even the choke opener which I think was tied into the fast idle unloader... it's been a while.

Other then that might want to check timing (Idle will be lower then normal if there is a vacuum leak) and other electrical things like battery wires and connections.

[itzdave]

if you live in a place without emissions, i would consider removing the black box. it could maybe help a little.

[dh89lx]

Hello all,

After sitting for months, I troubleshot the problem to clogged fuel filters apparently resulting from a bad tank of gas. I should have made that connection since it happened about a mile after a fill up at a station who had just taken a fuel delivery (stirred up seds from bottom of tank I suspect).

[dh89lx]

Replaced fuel filters, cleaned out the fuel tank, good as new!