My 1992 chevrolet silverado failed emmisions?

Question

Heres the results
ASM2525 TEST CURB IDLE TEST
LIMIT READING LIMIT READING
HC ppm 52 85 200 70
co% 0.29 0.05 1.00 0.00
NO ppm 735 522
RPM 1590 valid RPM 681 valid
dilution 13.7 valid DIlution 12.8 valid

I have installed a new pcv valve ,new plugs, wires, cap, rotor, any other suggestions the truck runs good other then a little bit of low rpm hesitation, thanks in advance for any help :-)

Answer 1

This may be really stupid, but I have to ask.
From the numbers you're presenting I'm assuming you failed the HC ppm because the limit was 52 and you got 85. This means you're not combusting all the Hydrocarbons or gasoline is not going to full combustion.

Your CO% informs me that you're using almost all the oxygen that the engine can take from the intake. The reading of 0.05 means almost no CO (carbon monoxide remains). It sounds to me like we're not getting enough Oxygen into the engine to combust the remaining HC.

You mentioned all those things you replaced, but the obvious question based on your data would be:

Have you tried replacing the air filter???
Engine needs Oxygen to finish combustion.

Answer 2

i ought to chosen the Silverado. i imagine it does fee extra and probable has worse gas mileage, notwithstanding it truly is extra of a each day motor vehicle. A Camaro is extra of a third motor vehicle (you and your spouse/husband has one and then you've a summer season activities motor vehicle aspect). The Silverado holds extra human beings conveniently and extra issues. keep on with 1500 because the subsequent one is 2500 HD, that is large. My buddy has a Ford f-350 7.3L engine and he cant do any city utilising with it. He has to end again it up and all of that in simple terms to exhibit right into a motor vehicle park.

Answer 3

Replace the O2 sensor.