Does anyone know of a source on the net that describes troubleshooting and adjustment steps for Honda feedback carburetors? After performing quite a few tests on my 1987 Accord to try and correct a excessive NOx problem, I think I may have narrowed it down to a few possibilities. BTW, I've already confirmed the EGR valve and related control and thermo valves are working properly.

It seems to be running a bit lean and I have a feeling the NOx section of the three way catalytic converter is not functioning properly due to this condition. I tested the O2 sensor using the propane torch method and it seems to be functioning properly, so I think it might be a problem in the carburetor's feedback system. The problem is, I have now idea where to look at this point.

I was considering adjusting the air/fuel mixture to see if this might help, but don't know where the mixture screw is on this carburetor. I also have no idea if the feedback system would cause any mixture adjustments to be compensated for, negating the effect of the adjustment.

How is the air/fuel mixture controlled in the closed loop feedback system?

Any input would be greatly appreciated. Thanks...


One last question from my other thread...

In the manual it says to remove the vacuum lines before adjusting the timing, but I've not found that to be practical. To do this you must raise the idle speed enough to allow the engine to run when the vacuum lines are removed and plugged. Once the timing is set and the lines are reconnected, the idle is way too high and needs to be reset. It also means the engine is very far advanced at idle. Is this the correct procedure? It sure seems wrong to me...




Modified by Ardfarkle at 2:35 AM 5/21/2004