emission fail-HCs

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emission fail-HCs

Postby h-bot » Wed Jan 15, 2003 2:17 am

From: cv2037_REMOVE_100383_THIS_@yahoo.com

Duke, I hoped you'd respond. Thanks for the help. Utah's test is a 2
speed loaded dyno test. As far as I can tell, 2037 is OEM. The plugs
look good but they are the wide gap and I didn't put them in so I
think I'll replace them with NGK TR5 as you've suggested in older
posts. I'll take a closer look at rotor & cap. I know the wires &
boots are old but they seem to be connecting OK. Could be bad wires
though.

Can I find new parts: rotor, cap,...? I've already tried to find
wires with no luck. Maybe I'll need to make my own.

As high as my HCs are, something must be way off.

Again, thanks for the help. This project (cv2037) wouldn't be
possible with some help.

Wendell




[This is message #10237 by user cv2037 on Yahoo! Group Cosworth Vegas: http://groups.yahoo.com/group/cosworthvegas ]
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emission fail-HCs

Postby h-bot » Wed Jan 15, 2003 2:26 am

From: markrock_REMOVE_497829_THIS_@yahoo.com

Wendell

In our experience, once the basics Duke mentions have been ruled out,
you are left with two other possibilities. One is the catalytic
converter. It is possible that a new converter will do a better job
of converting the unburned HC's.

On Dan's Cosworth, we had a similar problem. What I did was borrow a
friend's Exhaust Gas Analyzer, stuck it up the tailpipe, installed a
spare MAP sensor, and adjusted the MAP sensor to give the best
readings. I would have left in in place, but the car didn't run very
well that way, so after the test I removed it and put it on the shelf
to be reinstalled the next time a test was due. Finally I was able
to license his Cosworth as a Collector Car and no longer needed to
pass the test.

We had a similar problem with Ken's Cosworth as well, but it had
Webers. We had to change the idle jets in order to lean the mixture
sufficiently to enable it to pass.

The only other realistic possible solution I can think of is to
change the fuel in the tank when testing occurs. Someone, perhaps
Duke, once mentioned a product sold in Europe that has remarkably
clean burning properties. I've never seen that product here, but
there ought to be something that would burn cleaner. My two tricks
were to use premium gasoline, and to use a gasoline containing the
maximum allowable amount of ethanol. Whether those really worked or
not I cannot say scientifically, but that is what I did.

I must admit to having considered laying my oxygen bottle in the back
and running a hose through the firewall and into the mouth of the air
cleaner--they don't open the hood in Ohio--then cracking the valve as
I pulled in for the test. I figured I could get more complete
combustion that way, but never got desperate enough to try.

Mark




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emission fail-HCs

Postby h-bot » Wed Jan 15, 2003 4:17 am

From: doctorduke_REMOVE_393429_THIS_@yahoo.com

--- In <a href="/group/cosworthvegas/post?protectID=219233066105193209050199029077192253163098100009128121188190230091025019053061151110147">cosworthvegas@yahoogroups.com</a>, cv2037 <<a href="/group/cosworthvegas/post?protectID=091233212180056219138097203245129208071">no_reply@y...</a>> wrote:
> Duke, I hoped you'd respond. Thanks for the help. Utah's test is a 2
> speed loaded dyno test. As far as I can tell, 2037 is OEM. The
plugs
> look good but they are the wide gap and I didn't put them in so I
> think I'll replace them with NGK TR5 as you've suggested in older
> posts. I'll take a closer look at rotor & cap. I know the wires &
> boots are old but they seem to be connecting OK. Could be bad wires
> though.
>
> Can I find new parts: rotor, cap,...? I've already tried to find
> wires with no luck. Maybe I'll need to make my own.
>
> As high as my HCs are, something must be way off.
>
> Again, thanks for the help. This project (cv2037) wouldn't be
> possible with some help.
>
> Wendell

Cap and rotor are common to all other GM 4 cylinder cars of the era
and are commonly available from several suppliers. If they don't know
what a 122 CID CV engine is just order the HEI cap and rotor for the
140 Vega. They are the same.

Wires have to be made.

You should remove the complete high voltage wire harness and measure
all the resistances including the coil wire. Nominal is about 5K ohms
per foot. Also inspect all the terminals and boots very carfully. A
new set of NGK TR5s gapped to .035" should help. At least dress the
rotor tip with a small file and use a dental pick or Xacto knife to
clean the aluminum oxide off the cap terminals. For the money a new
cap and rotor would probably be worthwhile, especially if yours looks
well worn.

It will also help me with diagnostics if you post your other emission
component test results - CO and NOx - and the limits.

I have heard stories of fuel additives that supposedly improved
emissions performance, but I am very skeptical of the claims and have
never advocated them.

Duke




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emission fail-HCs

Postby h-bot » Wed Jan 15, 2003 4:18 am

From: doctorduke_REMOVE_563383_THIS_@yahoo.com

Also, if it was measured, post the 02 percent in the exhaust.

Duke






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emission fail-HCs

Postby h-bot » Wed Jan 15, 2003 5:27 am

From: longg01_REMOVE_471517_THIS_@yahoo.com

I'd bet the car would pass on two cylinders.
~CHRIS




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emission fail-HCs

Postby h-bot » Wed Jan 15, 2003 1:09 pm

From: cv2037_REMOVE_905990_THIS_@yahoo.com

I just brought old 2037 in for Utah emissions testing and failed on
the HydroCarbons.

1900 rpm 778 ppm/ allowable is 341
2164 rpm 910 ppm /allowable 311.

CO & NO passed

I thought it was running pretty good.

Anybody have any Ideas?

Wendell





[This is message #10234 by user cv2037 on Yahoo! Group Cosworth Vegas: http://groups.yahoo.com/group/cosworthvegas ]
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emission fail-HCs

Postby h-bot » Wed Jan 15, 2003 1:37 pm

From: doctorduke_REMOVE_349832_THIS_@yahoo.com

Assuing your engine is properly configured to OEM specs, HC only
failures are usually indicative of excess misfires, which points to
the secondary ignition components. Plugs, wires, cap, rotor are the
usual suspects, but you should inspect all the internal distributor
components, coil, and primary harness, too.

My #2110 in OEM configuration usually scored single digit HC counts
with the old two speed no load test. For the most recent test
conducted with California's current ASM loaded dyno test the HC count
is between 10 and 20 PPM. It would meet new car standards.

Duke




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