1992 b250 failed Ca. smog at 15mph
Thread Starter
|
Registered User
Joined: Jul 2013
Posts: 9
Likes: 0
1992 b250 failed Ca. smog at 15mph
1992 b250 failed Ca. smog at 15mph passed well at 25
HC 165 max 122
NOx 1086 max 707
Only 4,000 mi. since 2011 test. HC at 15 mph was close to max. NOx was great. Both tests CO was great dropped from 15-25 mph.
new oil, filters, pcv, breather,lucas gas additive.
ANY IDEAS??? THANKS.
HC 165 max 122
NOx 1086 max 707
Only 4,000 mi. since 2011 test. HC at 15 mph was close to max. NOx was great. Both tests CO was great dropped from 15-25 mph.
new oil, filters, pcv, breather,lucas gas additive.
ANY IDEAS??? THANKS.
Record Breaker
Joined: Aug 2007
Posts: 1,146
Likes: 1
Your statements regarding NO are confusing. 300+ppm over the limit, but great?
If you can post a photo of the printout that shows the 02% c02% and both 15 and 25 mph hc/co/no we would be able to give better help.
I just passed a test yesterday, with better numbers than my last 2 tests, except NO which I attribute to an Aging catcon. I am still well below the limit on Nox by a factor close to 5
The only tune up related Item I did since my last smog test was replaced the Bosch 02 sensor with an NTK. Bosch and Dodge do not play with each other nicely.
Another big contributor to HC is the 2 wire coolant temp sensor on the intake manifold. Bust out the ohm meter and test its resistance hot and cold, or just replace, quickly, as coolant will come out.
Do not run the Lucas FS cleaner during the test despite its claims of lowering emissions.
Make sure the engine is as hot as it can get for the test. Some say higher octane fuel will lower the emissions, some say not. Some say a gallon of denatured alcohol in 10 of gasahol will allow any vehicle to pass the HC portion of the test.
Do the key dance and see if the computer is showing any diagnostic trouble codes.
If you can post a photo of the printout that shows the 02% c02% and both 15 and 25 mph hc/co/no we would be able to give better help.
I just passed a test yesterday, with better numbers than my last 2 tests, except NO which I attribute to an Aging catcon. I am still well below the limit on Nox by a factor close to 5
The only tune up related Item I did since my last smog test was replaced the Bosch 02 sensor with an NTK. Bosch and Dodge do not play with each other nicely.
Another big contributor to HC is the 2 wire coolant temp sensor on the intake manifold. Bust out the ohm meter and test its resistance hot and cold, or just replace, quickly, as coolant will come out.
Do not run the Lucas FS cleaner during the test despite its claims of lowering emissions.
Make sure the engine is as hot as it can get for the test. Some say higher octane fuel will lower the emissions, some say not. Some say a gallon of denatured alcohol in 10 of gasahol will allow any vehicle to pass the HC portion of the test.
Do the key dance and see if the computer is showing any diagnostic trouble codes.
Record Breaker
Joined: Aug 2007
Posts: 1,146
Likes: 1
Thanks for posting that. I find it interesting how much different the allowable maximums are. Is yours a 3.9 or a 5.2 or a 5.9 liter engine?
Mine is a '89 with a 5.2 and I am allowed the same HC as you, but .50 and .64 on the CO% (yours are .72 and .64)and 1010 and 870 on the NOppm(yours are 707 and 609).
The averages listed are different on my test sheet also. On yours HC Average are lower, CO higher, and NO lower
My percentage of measured o2% is 2.7 and 2.5 and my HC's were 86 and 60. Your 02% is 0.4 and 0.2 and your HC's are 165 and 94
This suggests to me that my air pump is allowing further burning of the HC's in the catcon, and perhaps yours is not injecting enough/any air into it to facilitate the burning of the extra HC's and giving a low 02% reading at the tailpipe.
Notice on your earlier test, which you passed, had a higher O2 % of 1.7 and 1.8.
My c02 percentage was 12.6 and 12.7 respectively, the rpms about 40 lower than yours.
High NO is caused by excessive combustion chamber temperatures, The EGR valve, exhaust gas recirculation valve, diverts a portion of exhaust gases back into the combustion chambers to lower combustion temps.
I thought they visually had to check the proper operation of this valve on mine, but the guy told me yesterday that they only need check that it is present and the vacuum lines are connected to it.
When I returned the vacuum line to mine before the test, I could see ( with mirror and flashlight) that the pintle was not moving with the throttle input, and took it off and cleaned it and the vaccuum amplifier part, which was filled with water. After returning it, then the pintle did move with the throttle, with a small delay.
Air pumps go for about 50 to 80 dollars and are pretty easy to replace, except one or two of the bolts penetrates the water jacket of the engine and you will lose coolant replacing it. These bolts require some rtv on them and enough time to set up when returning them, or they will weep coolant.
The Air pump also has a diverter valve on it, controlled by vacuum, via a solenoid. When hot it is not supposed to inject air into the exhaust manifolds, but the catcon only. If injected into the manifold, then it will throw off the O2 sensor and cause the ECM to run a different A/F ratio.
I am hardly a guru at this, please do wait for input from others, but I would suspect the air pump is worn out. Replacement and a tankful of gas with some CRC guaranteed to pass, or techron, or redline SL-1 run through it should allow you to pass a new test. The above FS cleaners have the ingredient PEA, which cleans fuel system deposits, burns cleanly, and leaves no deposits of its own.
Some claim it also can clean an occluded catcon. I have no idea if true.
My best results on a smog test occurred after I drove 2500 miles in 3 days, cross country, and installed a new airpump the day of the test. All numbers were 1/10 or less of the maximum, suggesting that long drives are good for the catcon.
I thought a 92 and an 89, since they both have TBI and LA engines would have the same allowable smog PPM and % but they are different, suggesting there are differences in the motors. I do not know exactly what those differences are.
The Smog test is cheaper if you show up with the dog house removed and notify them before hand it will be so.
Mine is a '89 with a 5.2 and I am allowed the same HC as you, but .50 and .64 on the CO% (yours are .72 and .64)and 1010 and 870 on the NOppm(yours are 707 and 609).
The averages listed are different on my test sheet also. On yours HC Average are lower, CO higher, and NO lower
My percentage of measured o2% is 2.7 and 2.5 and my HC's were 86 and 60. Your 02% is 0.4 and 0.2 and your HC's are 165 and 94
This suggests to me that my air pump is allowing further burning of the HC's in the catcon, and perhaps yours is not injecting enough/any air into it to facilitate the burning of the extra HC's and giving a low 02% reading at the tailpipe.
Notice on your earlier test, which you passed, had a higher O2 % of 1.7 and 1.8.
My c02 percentage was 12.6 and 12.7 respectively, the rpms about 40 lower than yours.
High NO is caused by excessive combustion chamber temperatures, The EGR valve, exhaust gas recirculation valve, diverts a portion of exhaust gases back into the combustion chambers to lower combustion temps.
I thought they visually had to check the proper operation of this valve on mine, but the guy told me yesterday that they only need check that it is present and the vacuum lines are connected to it.
When I returned the vacuum line to mine before the test, I could see ( with mirror and flashlight) that the pintle was not moving with the throttle input, and took it off and cleaned it and the vaccuum amplifier part, which was filled with water. After returning it, then the pintle did move with the throttle, with a small delay.
Air pumps go for about 50 to 80 dollars and are pretty easy to replace, except one or two of the bolts penetrates the water jacket of the engine and you will lose coolant replacing it. These bolts require some rtv on them and enough time to set up when returning them, or they will weep coolant.
The Air pump also has a diverter valve on it, controlled by vacuum, via a solenoid. When hot it is not supposed to inject air into the exhaust manifolds, but the catcon only. If injected into the manifold, then it will throw off the O2 sensor and cause the ECM to run a different A/F ratio.
I am hardly a guru at this, please do wait for input from others, but I would suspect the air pump is worn out. Replacement and a tankful of gas with some CRC guaranteed to pass, or techron, or redline SL-1 run through it should allow you to pass a new test. The above FS cleaners have the ingredient PEA, which cleans fuel system deposits, burns cleanly, and leaves no deposits of its own.
Some claim it also can clean an occluded catcon. I have no idea if true.
My best results on a smog test occurred after I drove 2500 miles in 3 days, cross country, and installed a new airpump the day of the test. All numbers were 1/10 or less of the maximum, suggesting that long drives are good for the catcon.
I thought a 92 and an 89, since they both have TBI and LA engines would have the same allowable smog PPM and % but they are different, suggesting there are differences in the motors. I do not know exactly what those differences are.
The Smog test is cheaper if you show up with the dog house removed and notify them before hand it will be so.
Last edited by landyacht318; Jul 11, 2013 at 04:51 PM.
Van & CUV Section Moderator
Joined: Nov 2006
Posts: 5,372
Likes: 115
Trending Topics
Record Breaker
Joined: Aug 2007
Posts: 1,146
Likes: 1
My Magnaflow Ca legal Catcon was new and installed a few months before the 2005 test below and each test afterward, the NO has increased a bit, for the most part.
Wish I could find the '07 and '09 printouts for comparison.
Notice they lowered the allowable CO sometime between '05 and '11.
I guess all they will need to do to get these old vehicles off the road is lower the allowable emissions to ridiculously low levels that few could ever pass.
Obviously my faulty air pump diagnosis is a guess, and a less painful diagno$i$ than a new Catcon installed. I disconnected the new airpump after passing the first test, but the pump seized in the intervening 23 months before the next test. Not only that, but the check valves would fail and a portion of exhaust gasses would exit the air pump itself, sending me on a wild goose chase tracing mysto noises under the hood.
Now I just leave the belt connected and have the same pump since '07. but they do wear out, and they do make noise when new too, and it would be nice to not need them. If they are not working and the engine is running rich, it will wear out the catalyst faster.
I don't know if the program is still available in this broke state, but you used to be able to get money from the state to perform smog related repairs after failing, upto 500$, even if you had no problem affording it without help.
A friend of mine who could well afford it, got a new catcon for free, and the mechanic authorized some other new parts to max out the free allotment.
Wish I could find the '07 and '09 printouts for comparison.
Notice they lowered the allowable CO sometime between '05 and '11.
I guess all they will need to do to get these old vehicles off the road is lower the allowable emissions to ridiculously low levels that few could ever pass.
Obviously my faulty air pump diagnosis is a guess, and a less painful diagno$i$ than a new Catcon installed. I disconnected the new airpump after passing the first test, but the pump seized in the intervening 23 months before the next test. Not only that, but the check valves would fail and a portion of exhaust gasses would exit the air pump itself, sending me on a wild goose chase tracing mysto noises under the hood.
Now I just leave the belt connected and have the same pump since '07. but they do wear out, and they do make noise when new too, and it would be nice to not need them. If they are not working and the engine is running rich, it will wear out the catalyst faster.
I don't know if the program is still available in this broke state, but you used to be able to get money from the state to perform smog related repairs after failing, upto 500$, even if you had no problem affording it without help.
A friend of mine who could well afford it, got a new catcon for free, and the mechanic authorized some other new parts to max out the free allotment.