Topic: Operation SMOG: Fail

[87toyotaman]

Just got home from the smog shop. Didn't go as well as I hoped. Anyway he said i passed everything but the evaporative test. "theres got to be a line either disconected or split" he says from the gas tank to the canister under the hood. I passed my last smog check with flying colors. Any suggestions? I do have a 2" body lift that i thought was the problem, but I had that on last time.......and i passed  

[OOPS]

Check the line to find where it is cracked or disconnected.

[emsvitil]

Yep, it's either the line from the tank to the charcoal canister,  or the fill pipe from the gas tank cap to the gas tank.


The body lift may make it easier  to just replace the hose...........

[87toyotaman [OP]]

Thanks that helps

[PadawanYota_Stovy]

Smog is overrated me thinks . It seems to be only in Cali ha 

[87toyotaman [OP]]

Yea Arnold made it a bit more difficult this year passing the evap test

[johnny916]

the only real way to find out where it's leaking from is to smoke test. but if you choose not to then after you replace what ever you think it might be. drive it around, then take the gas off. when you ntake the gas cap off you should hear vaper pressor. if you don't hear any thing, you didn't fix the problem.
  if you need help, or don't understand, PM with and I'll call you.  I'm a smog tech.

[MC387]

I would look especially close at the rubber lines near T-case output.  They have a tendancy to get grease on them and deteriorate.  Also, make sure your filler neck is connected. And the clamp is tight.  One other thing to look at if you have the carb motor,is the canister purge valve.  I think it is on the PS fender.  It should be the one that is connected to the canister via a vacuum line.  I believe it is normally closed.  Therefore, when no voltage is applied it should not pass any air.  A vacuum pump would be best for this test, but you may be able to blow into one of the lines with the other one dosconnected and see if any air passes.  Do this with the key off.  If you have the RE motor, there is no purge valve.  If that is the case, the tech would have to pinch both the canister vent, and the purge hose.  If you find no other problems, i would make sure that part of the test is being done correctly.

[87toyotaman [OP]]

How do I know if the purge valve is bad. Air passes through both ways with the key off. One side allows a little bit more air passed than the other. When I shake it i hear what I think is a little bit of gas. Hope this makes sense. Thanks. May I have a bad purge or charcoal cannister?........

[87toyotaman [OP]]

ttt

[emsvitil]

The evaporative test doesn't test the charcoal canister or purge valve.


They test the cap (which they've been doing for years).

Then remove/plug or clamp closed the line that goes from the gas tank to the charcoal canister at the charcoal canister.   Put something in the gas tank filler and pressurize the system with Nitrogen and see if it holds pressure.

If it doesn't hold pressure, it's either the fill pipe, evaporative hose, or leak in tank (doubtful about a leaky tank).

[87toyotaman [OP]]

ttt

[crazykooter]

what emsvitil said is correct.  In my experience if it fails the evap then the 1st thing to do is replace the gas cap.  -If that isnt it then the next most likely place is the small line running from the filler to the tank.  It gets brittle after a while. Fairly easy to replace.  If you were near me I have like 3 tanks with good lines on them.

[87toyotaman [OP]]

Noticed after a drive the other day i heard the pressure release from the tank. Hope this is all. Will be testing it this week.