bills188

I have a 1987 Honda Accord DX with a 2 barrel carburetor. It has recently begun running very rough at idle when warm.

When cold it starts and runs normally. When it comes off fast idle it still runs very well and normally. Once it gets a little warmer, say after 6 miles, it runs poorly at idle and wants to stall at idle. On the road on throttle it runs well and has good power. When I let off the gas going down hill it backfires through the exhaust intermittently. It seems like it is running very rich at idle, with blue smoke coming out the exhaust until I rev it up enough so that the misfiring goes away. With some guidance from a friend who teaches automotive shop in another state, I'm suspecting it is a fault with the air injection system. My friend is suggesting it is symptomatic of a failed check valve or reed valve in the air injection system. I'm not sure which component it is or how to check it, or even if we are looking in the right direction.

It has been a great car over the 19 years I've owned it and it doesn't owe me anything. But if I can keep it running by spending a reasonable amount on parts I'll do it.

Thank you for your help.

Bill in Wayne, NJ

KING PIN

well from what i can remember on that car, there are tons of vacuum lines and any of them being bad can cause this, if it was me, i would buy a Weber 32/36 carb and be done with it. all you would have then is 2 vacuum lines and that's it. i love my 32/36 best upgrade ive ever done to my old 83 civic.

bills188

Thank you, King Pin.

That would probably solve the rough running issue but I need to keep the emission components intact in order for it to pass NJ state inspection. I am also hoping to keep the cost under that of a new Weber carb kit.

Regards,

Bill from Wayne, NJ

9/4/14- I have been searching for a post elsewhere regarding a similar problem. One mentioned checking the air suction valve by warming up the engine and disconnecting the vacuum line to the valve and checking for vacuum. Before disconnecting the vacuum line I hear the bubbling from the air intake hole in the air cleaner. When I disconnect the vacuum line the bubbling stops and there IS vacuum at the line. The post I found said that if there is bubbling and it stops when the line is disconnected and there is vacuum at the line, then the problem is in the control system. Unfortunately it does not detail how to check the control system. As far as I can see the control system consists of the air suction valve solenoid - a large black box with dozens of vacuum lines coming off it and the ECU. Neither part is available new from what I can see and I suspect they would be very expensive if they were. If anyone has an idea of what I could try from here I'd really appreciate the help.