I hate that my first post is probably going to be flamed to death. But I have spent countless hours the past two weeks reading different forums trying to fix this stuff on my own. So here goes...

I've never owned a Honda. A buddy needed some money so I bought a 97 ex from him that he just put a new rebuilt head on (d16y8, MT).
CEL was on so I pulled the codes with a jumper. I bought an OBD cable for my laptop but it's not here yet.
It pulled
14 IAC
23 Knock sensor
65 Secondary oxygen sensor heater wire (black wires)

The car revs from 1500 to 2500 rpm and then usually settles down to 1000 rpm.
After I drive it about 15 min at stop it will settle to 1500 and surge real fast. The rpm's don't really go up it sounds like bububububububub real fast:wacko:
If I restart the engine it stops for a while.
Also, it smells really rich and it sometimes pukes out carbon on the ground when I crank it up.
It seems to run well it has power. But the high rpm's and rich condition worry me so I have parked it.

So this is what I have done.
Cleaned throttle body. (no improvement)
Covered throttle body upper port (rpm's dropped to 600)
Cleaned IACV (no improvement)
Disconnected IACV (no improvement)
Adjusted idle adjusting screw (bottomed it out idle barely dropped, but engine would start to bog out under load)
Set ignition timing to the middle line on the crank (no improvement)

I don't really know what to do now. So any help would be appreciated.

 

Fix the cause of the trouble codes, go from there.

Get yourself a manual. I just flipped through my $15 Hayne's manual and looked up how to diagnose all of those sensors and it's really easy. All you need is a multi-meter.


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And a faulty secondary 02 sensor will not effect the way the eninge runs at all.

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Thanks for the reply
I have all the manuals
I tested the valve on the IAC per the Honda OBD Training Manual
23.5.1 To Cause the IAC Valve to Fully Close

If you want to test the IAC valve to make sure it will fully close down, you can temporarily unplug it. When you unplug the IAC valve the idle should drop to the base idle. When the car is fully warmed up, and is on base idle, all the air is being controlled on the idle bypass screw. If the idle air bypass screw does not seem to have total control over the idle, the IAC valve may not be shutting down completely, or there is another source of unmetered air.

23.5.2 To Cause the IAC Valve to Fully Open

If you want to test the IAC valve to make sure it will fully open, you can temporarily ground the wire that goes from the IAC valve to the ECM. One wire will read steady battery voltage, and one will have varying volts. The varying volts wire is the one you should ground. When you ground this wire, the idle should increase significantly.

You can also test the 2-wire IAC valve winding with an ohmmeter. Make sure there is no continuity between the winding and the case. Check for approximately 11.5 ohms on the winding itself..


Everything looked good.
I haven't tested the knock sensor though.
Think it would be worth it or focus on something else?

 

Any ideas?