High Carbon Monoxide Emissions (86 nissan pulsar nx)

Here is the story. I got a 1986 Nissan Pulsar NX from a friend. The emissions results back before it was taken off the road was:

Driving Hydrocarbons (HC): 71ppm (MAX: 314ppm) Driving Carbon Monoxide (CO): 0.26% (MAX: 2.41%) Driving Oxides of Nitrogen (NOx): 2655ppm (MAX: 3390ppm)

Idle Hydrocarbons (HC): 84ppm (MAX: 402 ppm) Idle Carbon Monoxide (CO): 0.10% (MAX: 4.54%)

Then the car was taken off the road because of a shot carburetor (would stall out and you'd have to pump the gas to keep it going), which i rebuilt, and the car drives fine, except i can't really get it to idle below 1000RPM (suppost to be at 650RPM). So i turned the idle speed screw up to about 1000 RPM so i wouldn't have to drive with two feet. Sometimes it stalls going around left corners, is this a sign of a low float level?

Anyway here is the current results:

Driving Hydrocarbons (HC): 247ppm (MAX: 314ppm) Driving Carbon Monoxide (CO): 8.56% (MAX: 2.41%) Driving Oxides of Nitrogen (NOx): 127ppm (MAX: 3390ppm)

Idle Hydrocarbons (HC): 73ppm (MAX: 402 ppm) Idle Carbon Monoxide (CO): 0.16% (MAX: 4.54%)

So driving hydrocarbons are up, but still below the max, driving carbon monoxide is through the roof, and driving oxides of nitrogen are barely there.

New spark plugs, dist cap, rotor, spark plug wires, pcv valve. basically i want the thing to idle and pass emissions. so what are my problems?

Reply to
jsanders
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High CO means excess fuel. Since it is only happening under load it could be improper carburetor assembly, high fuel pressure, high float level, worn jets, etc. Since you say you just serviced the carburetor I would imagine a gasket or o-ring that has to do with the high-speed circuit is not sealing, allowing excess fuel into the combustion chamber.

Chris

Reply to
halatos

snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@m73g2000cwd.googlegroups.com:

Doesn't this vehicle have throttle-body injection? The one my nieghbor had did.

Reply to
TeGGeR®

nope. this one was an e16s engine. its carbureted. the one you might be talking about is the e16i or e15 (e)t (dunno about that one)

anyway all the gaskets are new, but the jets didn't get changed. would high float level cause stall> snipped-for-privacy@gmail.com wrote in

Reply to
jsanders

Reply to
jsanders

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