Smog test whizzes: Pressurized tank = good cap? (1 Viewer)
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Still well short of my '94! First I knew of the new plug the car in and read the OBD was when I took my daughter's car in for smog. Hers is an '05.
no the pressure means that the check valves on your charcoal canister are blocked
The "gross polluter" stuff is just another shake down. Once you are a GP, the "red star" stations have you as their bitch forever.
This is Jerry Brown on his communist red star badge and it says "always ready" to screw you.
Here is his grandfather:
This is Jerry Brown on his communist red star badge and it says "always ready" to screw you.
Here is his grandfather:
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We here in Minnesota can thank our former gov. Jesse " the Body " Ventura for eliminating smog testing !
- Thread starter
- #26
umm, Pinhead, even though I have my own opinions about him, this is not the best place to put that kind of stuff.. Best if this thread stays in Tech in case it helps somebody else in the future, no?
You guys have me all confused now.
I thought the Hissing during removal of the gas cap was a sign of a bad charcoal canister? There have been other threads about that. Is this wrong?
Obviously, if pressure holds in the tank, it means the cap is doing its job, but doesn't the buildup of pressure relate to a plugged canister? I thought the point of the canister was to sort of filter the fumes before they get sucked into the engine for combustion.
I currently have this issue with my '92, so it would be nice to know. Also, since I don't smell gas vapor exiting the tank, I have to assume that the hissing I hear is actually vacuum in the tank pulling air IN does that make sense?
Thanks!
I thought the Hissing during removal of the gas cap was a sign of a bad charcoal canister? There have been other threads about that. Is this wrong?
Obviously, if pressure holds in the tank, it means the cap is doing its job, but doesn't the buildup of pressure relate to a plugged canister? I thought the point of the canister was to sort of filter the fumes before they get sucked into the engine for combustion.
I currently have this issue with my '92, so it would be nice to know. Also, since I don't smell gas vapor exiting the tank, I have to assume that the hissing I hear is actually vacuum in the tank pulling air IN does that make sense?
Thanks!
Wayne
Bought by His blood, kept by His power
Golgo13, I have the same hissing when I open my gas cap and it is pressure built up in the tank, not vacuum. The inlet valve in the charcoal canister is sticking causing the build up of pressure. With the engine off, the valve is supposed to open an a very low pressure to vent the tank vapors into the canister and out the bottom. When the engine is running, the VSV opens and supplies vacuum to the canister and suck the vapors into the engine, and clean air is pulled into the canister through the bottom. I'm with you about the gas cap issue in CA, very confusing. I thought a sealed gas cap was a good thing.
inkpot
SILVER Star
If you JUST pulled up to the gas pump, cut the engine off, and open the cap to pressure coming out, it means the system may be working just fine. How long should it take for the canister valve to SLOWLY release all of that pressure?
- Thread starter
- #33
OK, now I'm annoyed. I swung by the smog place I like best since I was next door and ask the guy if it was OK to have one incomplete monitor (the rules say it is) and he says something like it would be OK had I not told him. That didn't quite feel right but I let that slide. Then I asked about the cap test and he says yes he has to test it for a 97 and when I challenged that (nicely) he pulls out his rules book but that one dates from 2009 and the one I found online is 2013 so he's only 4 years behind the times.... 
At least it's a nice guy, that's something. But it's a like with a cop, it doesn't pay too argue too much so I held my piece...
Now, hopefully it's the automated system that decides whether he has to test the cap or not, but who knows... They can still fail you for subjective reasons, like too much oil on the engine and whatnot, though, if they don't like the color of your shirt apparently...
So I will drive a bit more to get all the monitors ready (it is the damn catalyst still lagging behind all the others) and take my 3 caps along.
Curse it all!
At least it's a nice guy, that's something. But it's a like with a cop, it doesn't pay too argue too much so I held my piece...Now, hopefully it's the automated system that decides whether he has to test the cap or not, but who knows... They can still fail you for subjective reasons, like too much oil on the engine and whatnot, though, if they don't like the color of your shirt apparently...
So I will drive a bit more to get all the monitors ready (it is the damn catalyst still lagging behind all the others) and take my 3 caps along.
Curse it all!
charcoal absorbs the fumes, which are then drawn into the engine and combusted.
Back in the day people had vented gas caps and would just let their fumes escape into the atmosphere. it wasn't good.
I guess if you don't smell fumes, it might be a vacuum. I'm not sure what would cause that.
When i got my '94, it would emit a thick cloud of gas fumes when i removed the filler cap. I put in that autozone canister and that fixed me up.
Some people have been able to open the factory canister, clean out the valves, and install new charcoal from the fish section of a pet store. i think basically they just used one of those no-sharp-edges style can openers. This sounds perfectly reasonable to me, and like something i might try if i had another rig with a clogged can.
OK, now I'm annoyed. I swung by the smog place I like best since I was next door and ask the guy if it was OK to have one incomplete monitor (the rules say it is) and he says something like it would be OK had I not told him. That didn't quite feel right but I let that slide. Then I asked about the cap test and he says yes he has to test it for a 97 and when I challenged that (nicely) he pulls out his rules book but that one dates from 2009 and the one I found online is 2013 so he's only 4 years behind the times....
Now, hopefully it's the automated system that decides whether he has to test the cap or not, but who knows... They can still fail you for subjective reasons, like too much oil on the engine and whatnot, though, if they don't like the color of your shirt apparently...
So I will drive a bit more to get all the monitors ready (it is the damn catalyst still lagging behind all the others) and take my 3 caps along.
Curse it all!
Find another shop, he doesn't know what he is doing...96-99 any ONE monitor incomplete, 00-up only evap can be incomplete. And NO cap functional. If he doesn't listen, I would call BAR while your there and hand him the phone....
- Thread starter
- #37
OK. Now I'm puzzled. I went through the actual smog test today and sure enough, the computer asked him to do a cap test. And the sheet shows my truck as being indeed a 1997, which the system gets from the VIN. I thought I had figured it out with the BAR web info, but maybe not. And yes, it is a Basic region, not an Enhanced test one.
I don't know what to make of this. What a...
I don't know what to make of this. What a
...
- Thread starter
- #38
But as to the original question of this thread, the Tech told me that having the tank be pressurized is indeed a good indicator that the cap will pass the functional test. He said he has never seen a cap holding pressure on the filler that did not then pass the test. One exception that he could see though would be if the seal has cracks and then fails the visual inspection while still holding pressure (or I imagine could be damaged by the test itself, not too likely).
OK. Now I'm puzzled. I went through the actual smog test today and sure enough, the computer asked him to do a cap test. And the sheet shows my truck as being indeed a 1997, which the system gets from the VIN. I thought I had figured it out with the BAR web info, but maybe not. And yes, it is a Basic region, not an Enhanced test one.
I don't know what to make of this. What a
The computer does ask to do a fuel cap functional because the software is outdated. The state is not going to put money into modifying the prompts. The state is focused on the new testing system and software. There is a list of fuel cap adapters the tech is supposed to chose from before performing the functional. He is suppose to select the "no adapter available" option to bypass this functional for 96 and newer.
Per state inspection procedures:
2013
Emission Control Functional Tests
Fuel Cap Integrity Test:
As prompted by EIS, perform the fuel cap integrity test on all 1976 to 1995 vehicles, equipped with evaporative controls that can operate on gasoline, including dual/bi-fueled vehicles.The fuel cap integrity test is a two part test. Visual inspection: As prompted by the EIS,inspect the fuel cap(s) for proper fit and installation.The inspection result entries are “P” for Pass, “F” for Fail and “S” for Missing. If the fuel cap threads are stripped or the fuel cap seal is missing or damaged, or the fuel cap is not designed for the vehicle, the fuel cap shall fail the visual inspection.
Functional check:
This check applies only to vehicles equipped with evaporative emission control systems. Check the fuel cap tester application manual to determine the correct cap adapter. Following the EIS and cap tester prompts, attach the fuel cap(s) to the adapter and perform the test. The test results are automatically captured by the EIS. If no adapter is available from the tester manufacturer (for the vehicle being tested), enter “No adapter available” as prompted by the EIS. For vehicles newer than 1995 do not perform the functional test, enter “No Adapter is available” as prompted by the EIS.
