CO Emissions Problem

[Joel A. Robinson]

Hi All!

I hope you don't object to my posting of this message, as it doesn't 
really pertain to DIY_EFI but I bet some of you can answer the question 
intelligently, unlike some folks on the newsgroups.

My girlfriend has a 1985 Toyota Tercel SR5 4WD wagon.  The car has over 
200,000 miles on it (2nd hand Japanese engine installed at 140,000 miles) 
and she is planning on dumping it soon.  In the meantime, it has failed 
emissions testing twice and she has 30 days to do something about it.

Below are the results:

       RPM     HC (ppm)        CO (%)          CO + CO2 (%)
Limits          <220            <1.20           >6.00

Test 1: 965       70             .05            10.55
        2537      90            1.98 (FAIL)     12.60


After cleaning 3 mo. old NipponDenso Sparkplugs, new aircleaner, carburetor
cleaning, new cap & rotor...

Test 2: 920       25            0.00            13.16
        2570     139            3.68 (FAIL)     17.08     


Boy am I glad I wasted an afternoon on the car so it could do even worse!!!

The carburetor is supposedly a sealed unit so adjustments are not possible?

My question is this:  What can I do that will improve the CO number 
significantly, cheaply, easily and even temporarily?

Here are my initial ideas:

1.  Lean out combustion mixture to increase combustion temperature

	A.	Remove air cleaner
	B.	Kink the fuel line
	C.	Add _______ to the fuel (Alcohol, NitroMethane, ???)

2.  Adjust spark plug gap  (Do I want more or less?)

3.  Will spark timing affect this or not?


I drive a 1984 Plymouth (Mitsubishi) Colt GTS Turbo that is fuel injected 
and has never given me any trouble with emissions.  Therefore my knowlege 
of cars is somewhat limited to how to trick them or otherwise enourage them 
to go faster--none of this irritating carburetor with a zillion linkages 
and dashpots!!!!

I appologize again for disturbing your otherwise high-tech discussion,

Feel free to email me directly to reduce traffic.

Thanks,


Joel Robinson
robinj at src.usbm.gov