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rockerarm Samba Member
Joined: December 16, 2009 Posts: 3552 Location: Los Angeles
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Posted: Fri Feb 24, 2012 6:59 pm Post subject: |
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Just talked with my friend who is a calif smog tech and the EVAP portion of the calif smog check on pre-96 cars involves a visual inspection plus a vacuum test of the gas cap and the evap system. So basically if everything is visually there and connected its the vacuum test that failed it. It may be just the cap not holding a vacuum. But I know as old as these cars are it is probably a multitude of issues.
Prior to tearing everything apart, I'd at least try and vacuum test the small hose that leads to the cannister and see if the entire sys will hold a vacuum. If it doesn't then try a cap.
Hope this helps, Bill. |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Fri Feb 24, 2012 10:58 pm Post subject: |
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Mohammed would have told him specically if the cap was bad. _________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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rockerarm Samba Member
Joined: December 16, 2009 Posts: 3552 Location: Los Angeles
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Posted: Sat Feb 25, 2012 8:11 am Post subject: |
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I'd like to raise a concern regarding the calif smog check. If they are installing an adapter onto the tank inlet for the purpose of a low psi vacuum check, the first generation of EVAP systems which began in 1970, the gas tank vents its hydrocarbon vapors openly and witout any valves to the air filter assy. Correct me if I'm wrong but unless the smog tech could "cap" the hose as it goes into the air filter there is no way to "close the sys" and achieve a vacuum, for the purpose of verifying good hoses.
I may go chat with some smog techs today.
Bill |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Sat Feb 25, 2012 11:55 am Post subject: |
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rockerarm wrote: |
I'd like to raise a concern regarding the calif smog check. If they are installing an adapter onto the tank inlet for the purpose of a low psi vacuum check, the first generation of EVAP systems which began in 1970, the gas tank vents its hydrocarbon vapors openly and witout any valves to the air filter assy. Correct me if I'm wrong but unless the smog tech could "cap" the hose as it goes into the air filter there is no way to "close the sys" and achieve a vacuum, for the purpose of verifying good hoses.
I may go chat with some smog techs today.
Bill |
Pretty sure it is a visual thing. I did a vacuum test on the vent system on mine to be sure I got all the hoses and that they did not leak. _________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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edhnb Samba Member
Joined: December 02, 2011 Posts: 210 Location: El Dorado Hills, California
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Posted: Sat Feb 25, 2012 12:05 pm Post subject: |
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interesting. he definitely did do a vacuum check. There was a big adapter on the tank inlet running the test.
I checked all of my hoses last night.. and the connections to the canister were definitely loose. I wish I would have known to check these before my test.. my mistake. I will run a vacuum test on everything before I go back... and if the inlet to the air cleaner does cause any issues... I may just plug up that hole.. _________________ 1977 Asi Riviera |
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rockerarm Samba Member
Joined: December 16, 2009 Posts: 3552 Location: Los Angeles
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Posted: Sat Feb 25, 2012 2:53 pm Post subject: |
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It's more than just a visual thing. It includes a funtion test of the gas cap and evap system on a OBD 1 car and older. The issue I raise is the first generation of cars did not meter the hydrocarbons back to the intake. Somewhere around the mid to late 70's they began metering the hydrocarbons back to the intake. A perfect example was the later 2L bus' had a vacuum cannister on the air filter assy. The vacuum hose was tee'd to the vacuum advance for the distrib. The reason for this was it was getting so hard to meet the idle sniff test the addition of unburnt hydrocarbons at idle was influencing the exhaust test. So by "valving" it one can admit the hc when desired. Make sense?
I talked with a few smog techs and some wouldn't even talk! At least one told me a seperate machine is used for the older cars. So, depending on the year of the car and how it is equipped the test would be different.
So, nerd, do you know if your car has a vac cannister on the air filter housing? If not then it is an early system and where the evap connects to the air filter, there must be a procedure to be able to "close" the system for a proper vacuum to be applied.
At a minimum, you need to determine what system your car has, buy or borrow one of those hand pump vacuum tools, and a working knowledge of the routing of the hosing.
Hope this helps, Bill. |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Sat Feb 25, 2012 3:14 pm Post subject: |
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Thank for the clarification Bill. I think this is a 1977 or 1978 bus so the system is similar to mine. We have a canister on the firewall. On top of the tank are two vent lines that crossover and run up into the air vents, thence down into a just forward of the licence plate thence to the cannister. The canister has large line coming from the shroud (on 1978 it comes from the 1-2 tin) and the purge line goes to the air cleaner. There is also a small vacuum line that shares a connection with the distributor that controls the purge.
Nerd - look at it this way - You are almost there BTW - since all you are checking is the vent hoses, it may be possible to lean the tank firewall rearwards after pulling the screws and access those hoses without having to remove the actual firewall. There may be just enough room to get in there if those hoses were bad. See the image below.
from Ratwell.com
_________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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rockerarm Samba Member
Joined: December 16, 2009 Posts: 3552 Location: Los Angeles
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Posted: Sat Feb 25, 2012 4:26 pm Post subject: |
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Thank you SGkent. Possibly prior to getting in behind the firewall, if one has the hand held vacuum pump, one could theoretically break the entire evap system down to smaller sys's to check for vacuum. I am sure at +30 years old nearly every hose is suspect, but to keep it as simple as possible try and check just the engine comp hosing. This is very interesting and many people out there can benefit from nerd's encounter with our smog program. Some people are very susceptible to the gas fumes and here with this vacuum pump can diagnose if the evap hoses, or anything gas tank related is at fault. |
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edhnb Samba Member
Joined: December 02, 2011 Posts: 210 Location: El Dorado Hills, California
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Posted: Sat Feb 25, 2012 6:01 pm Post subject: |
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This is awesome guys. Thanks for the help. I will report back with my findings as soon as my wife lets me spend a few hours in the garage. _________________ 1977 Asi Riviera |
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rockerarm Samba Member
Joined: December 16, 2009 Posts: 3552 Location: Los Angeles
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Posted: Sat Feb 25, 2012 6:16 pm Post subject: |
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nerd04 wrote: |
This is awesome guys. Thanks for the help. I will report back with my findings as soon as my wife lets me spend a few hours in the garage. |
Just do something your not supposed to be doing! He he! Gotta love the samba women for putting up with this.
Bill |
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Tcash Samba Member
Joined: July 20, 2011 Posts: 12844 Location: San Jose, California, USA
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Posted: Sat Feb 25, 2012 6:23 pm Post subject: |
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Hi if as previously posted by rockerarm there is no diaghram or check vavle, it will never pass a Evap test it would draw air through the air box. Strang it passed the first time. You need to block off hose #9 to isolate the tank in order to build a vacuum. If you can get a hold of one, the best way to test for leaks is a smoke machine. Although I have not tried it, I have read a fog machine will work as well. Good Luck |
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rockerarm Samba Member
Joined: December 16, 2009 Posts: 3552 Location: Los Angeles
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Posted: Sat Feb 25, 2012 7:12 pm Post subject: |
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Agreed, that may be ideal, but seriously, there should be some techs out there that know how to correctly smog an early car. There are probably a few ways to handle this. Nerd just needs to see what avenue is the best method for him and his situation.
Obviously on a car that's evap is metered it is easy to see how it funtions and is tested at a smog check with engine off. But I am curious as to how a smog tech pumps down a system that is vented to air filter housing. I mean I know how I would do it, but what does the state want it tested? The mystery continues! Bill |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Sun Feb 26, 2012 11:56 am Post subject: |
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rockerarm wrote: |
Agreed, that may be ideal, but seriously, there should be some techs out there that know how to correctly smog an early car. There are probably a few ways to handle this. Nerd just needs to see what avenue is the best method for him and his situation.
Obviously on a car that's evap is metered it is easy to see how it funtions and is tested at a smog check with engine off. But I am curious as to how a smog tech pumps down a system that is vented to air filter housing. I mean I know how I would do it, but what does the state want it tested? The mystery continues! Bill |
The tech has legitimately tested and passed our 1977 bus several times as well as other cars we own. I cannot speak highly enough of him. He loves old cars and knows his stuff. Our bus had not passed smog since 1996 when we bought it in 2008 and the state would not issue anymore exemptions to it nor would they license it to me until it passed smog. I fought very hard just to get a 30-day temporary permit to be able to get it smogged. The DMV wanted 1-day permits only because it had failed so many times for the PO. Frankly they wanted our bus off the highway and scrapped. They flat told me that they were done with it since it hadn't passed once in so many years. We ran maybe 4 or 5 pretests getting thru all the issues including multiple bad rebuilt AFM's from a well known source in the industry. This tech never got discouraged with helping us get thru this. He met his wife and they dated when he owned a VW bus and he is very partial to them. Trust me, it isn't the smog guy. IMHO if anyone is at fault here it is the state air board. They fine these shops for helping people so it is a $10,000 risk every time a smog shop helps a customer fix something and pass the test rather than just flunk them. The air board cannot allow 100% of cars to pass or they would not be needed. I know of one shop in town that got fined on an undercover car for letting the undercover agent know the gas cap was bad and offering to hold the test open 10 minutes to let them run down the street to a FLAPS to get a new cap. Another shop got hit with a fine on an undercover car for putting a vacuum hose back on that had fallen off (been taken off by the undercover agent) and passing it rather than flunking the car outright and just telling the owner the vacuum hoses need work. This is one of those cases where our instincts tell us the laws and regs enforcing these things are poorly written which makes enforcement cruel to all of us - including the smog shops. _________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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Chris_914 Samba Member
Joined: September 16, 2011 Posts: 344 Location: Las Vegas
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Posted: Sun Feb 26, 2012 12:44 pm Post subject: |
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SGKent wrote: |
from Ratwell.com
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Hopefully it's one of the various small connector hoses. I just found #6 and #7 for the filler are crack and leaking on my '75 camper when filling up. Unfortunately Nevada is '67 and older exempt but we just have to pass a tail pipe test on pre ODBII. My '75 914 2L has passed with a progressive and dual 40s. I am on my 30 day permit now to get everything tuned to pass on the camper. |
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rockerarm Samba Member
Joined: December 16, 2009 Posts: 3552 Location: Los Angeles
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Posted: Sun Feb 26, 2012 3:26 pm Post subject: |
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Thanks SGkent for your info explaining what's going on out there. I applaud you and, you said, Mohammed for their perseverance. I have been on both sides of the fence and have had to carry out some distasteful decisions made by the state's smog guys. Certain people will strive to preserve our older cars while others will fold at the hands of the gov't's regulations. One advantage to this site is that people who may not be able to repair/improve their old cars have an avenue to pursue. Let's learn how nerd is able to get his Bay smogged. |
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edhnb Samba Member
Joined: December 02, 2011 Posts: 210 Location: El Dorado Hills, California
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Posted: Fri Mar 02, 2012 2:24 pm Post subject: |
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Ok, I have secured all the hoses I could reach.. and there were a few that had pretty bad connections, so I am hoping that solves my problem.
One more question that may be related. My idle once the bus warms up sits around 2k.. which is high. I tried searching.. but came back with too many unrelated threads.
I would hate for the bus to fail smog due to a high idle now.. so before I get re-tested I would like to fix this. Any ideas where I should start?
Thanks _________________ 1977 Asi Riviera |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Fri Mar 02, 2012 2:50 pm Post subject: |
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Hmmmn. Did you knock any hoses loose? Is the cable letting the throttle body return? Does it respond to turning the big screw in on the throttle body? We'll be home all weekend if you run into trouble. _________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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rockerarm Samba Member
Joined: December 16, 2009 Posts: 3552 Location: Los Angeles
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Posted: Fri Mar 02, 2012 2:58 pm Post subject: |
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nerd04 wrote: |
Ok, I have secured all the hoses I could reach.. and there were a few that had pretty bad connections, so I am hoping that solves my problem.
One more question that may be related. My idle once the bus warms up sits around 2k.. which is high. I tried searching.. but came back with too many unrelated threads.
I would hate for the bus to fail smog due to a high idle now.. so before I get re-tested I would like to fix this. Any ideas where I should start?
Thanks |
Good work nerd, but really if you intend on yourself performing the repairs, you really need to verify your work. There is a hand held vacuum pump so as a tech can basically test/diagnose the "plumbing" for your EVAP system. You can ask most shops to veiw there's I suppose but many techs will buy from the tool trucks, such as Snap On, Mac, Matco. Independent tool stores will probably sell one at less $$.
As far as your high idle, you're correct as this is a fail thing. A common idle we see is the vacuum deceleration valve hanging up. You can test by squeezing the hose with a needle nose and see if the idle drops. Another item is the Auxillary air regulator, but I doubt it would cause this high an idle. Also make sure there is no vacuum at the vac advance at idle. And make sure the throttle plate is closed.
Hope this helps, Bill. |
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edhnb Samba Member
Joined: December 02, 2011 Posts: 210 Location: El Dorado Hills, California
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Posted: Fri Mar 02, 2012 4:24 pm Post subject: |
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Thanks guys,
It turns out the big idle adjust screw solved my idle problem (thank you Steve & Bentley). For giggles I tested the decel valve.. and it seems to be working.
So an update.. I just FAILED again. but some good news.. the EVAP system passed this time.
So this time my results showed my CO% at 2.56 @ 15mph, & 2.46 @ 25mph. So my numbers are quite a bit higher than what's allowed.
Also, my NO(PPM) was a bit high, although in the allowable range (1265). _________________ 1977 Asi Riviera |
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rockerarm Samba Member
Joined: December 16, 2009 Posts: 3552 Location: Los Angeles
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Posted: Fri Mar 02, 2012 5:23 pm Post subject: |
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Ok. You are too rich and/or your cat isn't reducing the CO. Was the exhaust, IE: cat converter HOT, as some cars really need to be hot in order for the cat to be effective. I've even heard that the aftermarket cat converters are only good for a couple of years.
The basics you can check are the cyl head temp senser, AFM, fuel pressure, and if an injector, or cold start valve is dripping.
Your NO, or actually NOX, being high can be contributed to high cylinder head temps which are reduced by the EGR's function.
You should try and find a shop that will work with you as far as a sniff test to see if the CO and HC are within standards prior to another official test. I was talking to a well respected shop owner here in LA and he informed me that these late bus' are getting very difficult to comply with the smog check, as many parts are no longer available.
AINT CALIF FUN?
Hope this helps, Bill. |
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