I have a 94 accord stick shift with 140,500 miles. When I'm driving and I push in the clutch to coast, my engine dips in idle, below the 500rpm mark, and then goes back to normal idle, then dips again. It shakes pretty bad when it dips. When I come to a complete stop it dips then returns to regular idle and stays there. There is a little vibration at normal idle. I have replaced the plugs, wires, cap and rotor, fuel filter, and pcv valve. Other than the idling prob. it runs great! What could be causing this, is it just old age or is there an underlying problem that I do not see. When I bought the car ( @106,000 miles) it ran soo smoothly at idle you couldn't even tell if it was on. HELP

 

Had the same problem on my 92 lx with 125000 miles on it.

Been p***ing me off for months, so I finally took a crack at it. Fisrt I
thought it was the EACV, so I removed that and it had alot of carbon
buildup on the screens. Thought, great, cleaned it and reinstalled ( simple )
and it ran just as bad. However, in the process, discovered that the car would
not idle with the EVAC disconected. To set base idle, you disconect the EACV
and set the idle - shut the car off,reset the ecu and reconnect the EACV, then start it up again and observe.

Sooo - long story short - took a screwdriver and increased the idle ( idle screw in the throtle body ). Took a couple of trys until it stayed idling, then adjusted it to
specs ( ie looked at the tach -very acurate ). Shut er down and reconected everthing and started it up . Problem gone, smooth idle ; very sweet fix.
net cost, couple of hours and a can of carb cleaner.


Hope this helps


Modified by bushrat at 7:37 PM 7/27/2004