so I have a friend that has a 92 accord with 307, 000km's and his car recently has developed a really bad idling/misfiring issue.

When his car is idling after warmup the idle bounces all over the place like high/low/high low and it also reeks of rich exhaust. It almost sounds as if its sort of misfiring. We have tuned up the car and have done cap and rotor and have even cleaned the IAC valve and turned the wax ring back to the seated position on the high idle dashpot.

Anyone here know what the heck would cause an intermitted misfire and the bouncing idle? Its a canadian accord 4 cylinder and it is not throwing any CEL codes.

thanks

 

Did somebody tighten up the throttle cable? It should have a little slack in it.
Did you unplug the IACV to see if the rpm drops a couple hundred?

 

yes when I unplug the iac the idle goes stable and stops bouncing around but the engine still sounds like its misfiring too so I'm not sure what the heck is wrong.

Thanks

 

Did you ever determine what caused this? My 1991 Accord SE is doing the same thing. I'm guessing maybe it's an igniter failure.

 

Okay, you said you screwed in the FITV seat. But with the engine warm can you still hear air bypassing in it? If so replace it. It really sounds like you are getting too much air in the intake somewhere. Spray around with some carb cleaner to check for vacum leaks.
The block is full of coolant and burped thru the 12mm Bleed screw at the T-stat housing?

 

same problem

 

as far as the idle, as said above check your fitv, and also vacume leaks. the smel is the extra fuel from the miss fire I would think. cheack your spark plugs, wires, cap, and rotor.