rhodes2010

I would like some advice on how to reduce the fuel richness on the 92 accord.
My California Smog Test failed with fuel too rich.
Should be .75 - coming in at 5.0.

Any ideas ?
A sensor ?
A fuel adjustment.

Car runs and drives, with numbers that far off I would have thought problems.
Have not checked plugs for color.

Duane_in_Japan

We need your 5 gas readings at both speeds if you had a two speed test, was your cat convertor good and hot when you did the test, you drove right in and hooked up, no down time and almost no idle time.

EDIT
They are required to check timing, did they tell you if timing was on the mark too, when was your last oil change. I am going to guess that this is a test only station and they are not allowed to help diagnose at all but they should have given you a printout of the test results, yes.

AGAIN
when was your last tuneup.

rhodes2010

Okay I got the paperwork now. Here goes:

Test M1 15mph

RPM 1810
%CO2 11.5
%O2 0.6


HC PPM
MAX 118
GP 293
MEAS 196

CO %
MAX 0.75
GP 2.25
MEAS 5.01 <<<<< Concerned about this one


NO PPM
MAX 799
GP 2002
MEAS 717


Test M2 25mph

RPM 2489
%CO2 12.6
%O2 0.8

HC PPM
MAX 93
GP 243
MEAS 114


CO %
MAX 0.63
GP 2.13
MEAS 2.87 <<<<< Concerned about this one

NO PPM
MAX 738
GP 1802
MEAS 1208

Looks like CO% is the one that is off. My wife said fuel, sorry about that.

So it looks like we are over on CO on both tests, although we are also over on NO
at high RPM and HC on both (over the MAX at least).

Really appreciate this help.
On the Pass Fail for components it says the gas cap is failing, I'll get that tomorrow.
My engine light is also on and the trouble code keeps coming up 6 which my
Haynes manual says is water temp sensor related, tested it, checks out.
Car had no main radiator fan when purchased. Installed new one and it stays on all the time. Purchased used fan timer module, made no difference, swapped relay, made no difference.

Car is new to us do not know history, never have done a tune up yet.
Over 200,000 miles. I suppose I should do air filter and plugs.

Looking forward to input on this.

Modified by rhodes2010 at 11:11 PM 10/3/2007


Modified by rhodes2010 at 11:12 PM 10/3/2007

Duane_in_Japan

Looks like the fan thermo switch is bad near the thermostat ECT sensor, unplug it and the fan may quit. I will look into your gas readings.

Honda-Master

if there is a code 6 TW sensor,, what it does ,it is telling the computer that coolant temp is still cold thus computer richens the mixture ( like when you start car for the first time ) thus the co readings are going to be too high,,
you should look into and repair code 6 first ..
replace TW sensor, clear computer , drive the car and see if chk engine lite comes on again..

Duane_in_Japan

This may be a little difficult to understand but I will try to explain how Honda uses the TW sensor in open and closed loop.

Like every engine, the ECU has a map built in to attempt to make the least amount of emissions possible while the engine is cold and during the warm up process, Open Loop Operation, the TW (ECT) sensor has high authority (high priority) in telling the computer how much fuel to deliver the cooler engine (richer).

A Honda is a speed / density system, MAP sensor, once the engine enters Closed Loop Operation, fully warmed up, the TW sensor plays no role what so ever, other cars may go back into Open Loop if the sensor goes cold again due to its malfunction, but Honda will not. Now for the trick, if a Honda TW goes cold, you dont know it until you turn off the engine and try to restart after a short hot soak (engine still warm or even hotter than when you turned it off), now during cranking, the ECU looks at the TW sensor for how warm the engine is and delivers fuel accordingly, way too rich for a fully warmed engine and you have a situation that may be slightly rich, MAYBE LIKE YOURS, or be way rich and the car spits and sputters and maybe will not run at all, there is a procedure to prove this TW sensor is cold without testing it per se', pull its connector and I THINK you install a 330 ohm resistor (radio shack) into the connector to simulate a fully warmed TW resistance and if the car starts and runs fine then you have a bad TW sensor.

If the TW sensor does not go open or shorts out then it is very possible that it will not ever trip the CEL or ever set a code because it may only be slightly out of spec and you wont know it. Got a little bored tonight and thought I would throw that little bit of theory in there. Honda had many ECT sensor problems before they started to call it the TW sensor, but problems do still arise.

Once again please, tune up and recent or fresh oil change.