Emissions Help

[So Cal Mark]

all you have to change is the air jet and idle jet. Don't fool with the emulsion tube or main jet. Go up about 2 sizes on the primary air jet and use the 50 idle jets on both sides and you should be okay.

[ROOK1]

Thanks Mark! Do you sell Jets? If so let me know how much.

[ROOK1]

Well I finally passed. My jets came I bought a 205 and a 210, I decided to go with the 210 to start and here are the results. Major improvement on the high speed test. Idle test big improvement on the CO% little worse on the HC (ppm) but it passed.

High Speed test: HC (PPM)----CO%----CO2%----RPM
--------Standard----700 ------- 5.00-----N/A-----2503
--------Reading-----095 ------- 0.92 ---- 13.1
--------Deviation---605 ------- 4.08
--------Result-------Pass--------Pass
Idle Test
--------Standard----700 -------- 5.00-----N/A-----1080
--------Reading-----623 -------- 0.31 ---- 10.8
--------Deviation---077 -------- 4.69
--------Result-------Pass--------Pass

Thanks for all of your help.

[So Cal Mark]

a bit of a lean misfire at idle, that accounts for the high hc but the important thing is that it passed. Now, richen it up a little for best performance

[ROOK1]

Will do. Should I go back to the 195 or to the 205?

Thanks again!

[mdrburchette]

Congrats Rook! Now you can try both jets and see which one works best for you. It would be hard for Mark to tell you which jet is best for your car since they all perform so differently. Case in point, my 72 Spider with a higher performance engine takes smaller main jets than my 71 with a worn out engine. Who'd a thunk?

[So Cal Mark]

I'd go to the 195, but you certainly don't want it as rich as it originally was

[ROOK1]

Reviving my old thread with a new problem.

I have failed emissions once again. Here are the readings.

High Speed test: HC (PPM)----CO%----CO2%----RPM
--------Standard----700 ------- 5.00-----N/A-----2610
--------Reading-----447 ------- 10.07 ---8.0
--------Deviation---253 ------- 5.07
--------Result-------Pass--------Fail
Idle Test

No results.

Here are the pass results last time I had this issue.

High Speed test: HC (PPM)----CO%----CO2%----RPM
--------Standard----700 ------- 5.00-----N/A-----2503
--------Reading-----095 ------- 0.92 ---- 13.1
--------Deviation---605 ------- 4.08
--------Result-------Pass--------Pass
Idle Test
--------Standard----700 -------- 5.00-----N/A-----1080
--------Reading-----623 -------- 0.31 ---- 10.8
--------Deviation---077 -------- 4.69
--------Result-------Pass--------Pass

I have not changed anything since I had this problem before and have been passing every year since.

Why would the co% go up so much?

Any ideas?

[mdrburchette]

Why in the world are they emission testing such an old car? In NC I don't even go in for a safety inspection any more.

[ROOK1]

I could avoid an emission test and safety inspection, but to do so I have to register the car as an antique and run a special plate that has a model t on it. I prefer my black plates from 1971, so I have to jump through the hoops. Stupid Utah laws.

[So Cal Mark]

10% co is WAY too high for any kind of efficient running much less a smog test pass. At that level you will foul spark plugs and load up the engine with carbon. You may have a loose idle jet,, choke stuck shut, improper float level or sinking float. It would be advised to get that fixed promptly

[ROOK1]

I don't think it's the float as idle was great. Choke was stuck and it read 12%+. Would the idle jet affect the high speed and not the idle?

[ROOK1]

Here is where I am at now. Changed the air jet to 195

High Speed test: HC (PPM)----CO%----CO2%----RPM
--------Standard----700 ------- 5.00-----N/A-----2498
--------Reading-----213 ------- 0.81 ---- 13.4
--------Deviation---487 ------- 4.19
--------Result-------Pass--------Pass
Idle Test
--------Standard----700 -------- 5.00-----N/A-----1144
--------Reading-----952 -------- 0.32 ---- 10.8
--------Deviation---252 -------- 4.68
--------Result-------fail--------Pass

What should I do now?

[ROOK1]

Still working on this problem.

Denise or Mark or anyone in the know. What is the little needle with a nut at the base of my carb? Will this maybe help my issue?

Thanks in advance!

[So Cal Mark]

you have a lean misfire at idle. Turn the idle mixture screw out until the idle smoothes out