Hi gang, has anybody here heard of and or has experience with a product called CRC-Guaranteed-to-Pass-Emissions Test?
Reason I ask is I have inherited a 1985 GMC Sierra Classic 1500 that had failed smog test, It is completely stock and original, has a 305 backed by an automatic(I'm guessing it is a TH350). It is a California truck with a cat converter. The cat and Flowmaster muffler are supposed to be fairly new.
Thank you in advance for any responses,
THUMPER>>>>>>>>>>>>>>>>>>>>.
TRYING TO PASS SMOG
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Well, CRC's only guarantee is your money back if it doesn't work. However I believe that the Guarantee to Pass is only an injector/intake valve/combustion chamber cleaner. Your issues may infact be the FlowMaster Cat as these are not always California certified...or meet California emissions.
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We have similar emissions standards in Ontario as CARB and the CRC stuff is peddled here and never works. If you can provide me the numbers from your test to indicate what is the problem Eg: High NOX or High Hydro Carbons I can better advise you what to try to get it to pass.
Eg: Retarding the timing etc.
Also is this Throttly Body injection or Carb?
Something else to consider - When you bring this vehicle in for testing, are you going for a decent drive first in order to get your Cat properly heated up? I had to do this with my last car - Drive it around for about 15-20 minutes, and as I sat in line, keep the engine at about 1500-2000 RPM to keep the Cat hot. Worked fine.
Beyond that, I'd say that if it still doesn't do the trick, then rather than spending your money on the CRC product, put it into proper diagnosis and repair. Might even be something as simple as new plugs.
Hi Char, thanks for the quick reply.
Hi Stevie, thanks for the quick reply, I don't know why the truck failed on the previous test and my nephew did not hang onto the paperwork from the test center, this truck has a 4bbl carb and HEI ignition( I had to replace the module, also the p/u is new).
At $8 a bottle I might be tempted to try this stuff right before an oil change to keep things nice and clean. Maybe a one two punch btwn this and a bottle of Techron back to back.
Thank you SirTanon, when I take it for the test I will follow your advice, I also put new plugs in it when I changed the distributor parts (cap, rotor, module and pickup). The plug wires were replaced by my nephew and were still like new.
Hi Satin, I just might give it a try, the reason I posted the question is because it was recommended by one of my nephews friends and I have never heard of it before.
You may want to find a smog station that advertises "pay if you pass". This way, when you most likely fail, you will know the reason without shelling out more money.
Good luck. California has been tightning the max alowable emissions in an attempt to get older cars off the road. That truck was originally built to pass with say 400ppm of hc. Now they want it to pass 100ppm. Something it was never designed to do.
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When you change distributor you have to set the timing.
Right now you don't even know if it failed the visual check or the tailpipe meter, and if the latter which of the pollutants. If some part is not CARB compliant, pouring stuff into the gas tank isn't going to fix that.
Originally Posted By: SirTanon
Something else to consider - When you bring this vehicle in for testing, are you going for a decent drive first in order to get your Cat properly heated up? I had to do this with my last car - Drive it around for about 15-20 minutes, and as I sat in line, keep the engine at about 1500-2000 RPM to keep the Cat hot. Worked fine.
Beyond that, I'd say that if it still doesn't do the trick, then rather than spending your money on the CRC product, put it into proper diagnosis and repair. Might even be something as simple as new plugs.
Carburetor or fuel injection ? That's about the year when they were switching over.
Do Cali stuff all the time, not that I like it ... But, the air is cleaner (except for smoke right now ...). The SMOG checks helped a lot with that. You can usually see across the So Cal basins on most days 
So this is GM's last carburetor year for that truck. W/o the paperwork, we don't know what the "fail" was ... Most likely, if it made it past the visual, could have a leaky gas cap (fumes/won't hold pressure), or that the engine needs a serious tune-up.
All the carburetor functions must be there. Choke stove is a biggie. If the choke is not operating absolutely correctly, it won't pass.
You swapped a module in the HEI. OK, there are bunch of things to check in the HEI as we now have to have "rolling road" tests. That means the advance curve needs to be good. No hick-ups in how the advance comes in, no flat spots in the fuel mixture, etc.
PM me with a real email address, and I'll send you what I have on HEI rebuilds and timing info ...
The next thing to look at is cold start. After sitting over night, does it smoke? That would be valve seals. Does it smoke on decel or going down a grade? That would be rings or leaky intake manifold.
Have you changed the PCV valve and ALL the vacuum hoses? Any vacuum leak will throw things off ...
New clean oil and a filter (hopefully HDEO 15W-40 Delo 400 LE). Best oil I have found to get old SBC's pass SMOG ...
Tranny could be either, but many trucks got TH400, even with 305
So this is GM's last carburetor year for that truck. W/o the paperwork, we don't know what the "fail" was ... Most likely, if it made it past the visual, could have a leaky gas cap (fumes/won't hold pressure), or that the engine needs a serious tune-up.
All the carburetor functions must be there. Choke stove is a biggie. If the choke is not operating absolutely correctly, it won't pass.
You swapped a module in the HEI. OK, there are bunch of things to check in the HEI as we now have to have "rolling road" tests. That means the advance curve needs to be good. No hick-ups in how the advance comes in, no flat spots in the fuel mixture, etc.
PM me with a real email address, and I'll send you what I have on HEI rebuilds and timing info ...
The next thing to look at is cold start. After sitting over night, does it smoke? That would be valve seals. Does it smoke on decel or going down a grade? That would be rings or leaky intake manifold.
Have you changed the PCV valve and ALL the vacuum hoses? Any vacuum leak will throw things off ...
New clean oil and a filter (hopefully HDEO 15W-40 Delo 400 LE). Best oil I have found to get old SBC's pass SMOG ...
Tranny could be either, but many trucks got TH400, even with 305
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His '85 305 has that darned electronic Quadrajet-I had an '85 305 in a van back when we had smog tests here in OH, used to do an oil & filter change & take it straight to the testing station, that generally did the trick, unless the carb was FUBARed (which happened a LOT). An '85 still gets tested? Can't believe a 32 year old car isn't exempt!
Originally Posted By: bullwinkle
His '85 305 has that darned electronic Quadrajet
Calif. doesn't have a 25+yr old exemption?
Originally Posted By: sleddriver
Calif. doesn't have a 25+yr old exemption?
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