hidesertwheelin
1/2 ton status
How in the hell do I even begin to diagnose it? I have no visible fuel leaks.
CK5
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Failed Cali EVAP test
- Thread starter hidesertwheelin
- Start date
You buy a new EVAP cannister.
mine did the same the first year they added this test. I had to change the vent valve on top of the tank. Check the line from the charcoal canister to the tank. It can also be in the cap if it is not sealing. The test puts pressure in your tank. The test covers the tank, filler, vent for the filler and the line to the charcoal canister, but not the charcoal canister. I feel your pain.
Last edited:
hidesertwheelin
1/2 ton status
That won't solve the problem. I need to locate the the leak. The hose to the evap canister is pinched off for this test.
They do test the EVAP cannister and MANY fail. Are you sure this isn't what failed? If not then you need to check ALL fuel hoses including any vent hoses AND the gas cap itself.
Don't you love that we get the pleasure of paying for this new diabolical test. What a load of BS. I recall that they test the gas cap separately, then use their own gas cap that has the adapter to the nitrogen feed for the pressure. I also recall that they do clamp off the canister. I would study the emissions hose routing to understand what exactly is pressurized and what the test is doing. You can try to isolate systems, but w/o an ability to duplicate the test, it is difficult to diagnose.
best of luck to you,
best of luck to you,
Well, living down here in sunny oil soaked Fl. I don't usually worry about such things.
We don't have smog checks or vehicle inspections.
I kinda miss the inspections we used to have. It was fun watching a "tech" drive my Jeep through the back wall of his shop and into the parts store on the other side.
Told him to let me do the brake test.....
Anyway, just for fun, I looked up the Ca. EVAP test. Looks like it should be fairly easy to find the problem.
Maybe not so easy to fix.
If you have anybody in your area with a smoke generator, that is about half the job done.
If not, your gonna have to get creative.
First, go to the local junkyard and grab a fuel cap or two to fit your truck. Tear one apart, and figure out how the vent works.
You need to convert one into a non-vented adapter. Weld, glue, hammer shut, any and all vents. Drill a hole and attach whatever fitting makes life easy for you.
Make a gasket to go inside the cap so when its put on the filler tube, it gets a good seal.
Seal off the hose going to the canister that they sealed off. Mix yourself up a mix of dish-washing soap and water into a spray bottle.
Put the modified gas cap on and pressurize the tank.
DON'T go crazy here.
They use 1/2 psi.
The fuel system was not designed for high pressure.
If you are using a Schrader (tire) valve, just a quick shot with an air hose should do it.
Then, start spraying every rubber hose and tank fitting you can find.
When you see bubbles, you have found it.
But keep spraying, odds are you have more than one.
If you don't find it on the first try, odds are its so big that the pressure did not last.
Wet everything down with the soap again, and have someone watch while you give it another shot of air.
After checking to be sure the first shot has actually run out. Don't overpressurize the system.
J
We don't have smog checks or vehicle inspections.
I kinda miss the inspections we used to have. It was fun watching a "tech" drive my Jeep through the back wall of his shop and into the parts store on the other side.
Told him to let me do the brake test.....
Anyway, just for fun, I looked up the Ca. EVAP test. Looks like it should be fairly easy to find the problem.
Maybe not so easy to fix.
If you have anybody in your area with a smoke generator, that is about half the job done.
If not, your gonna have to get creative.
First, go to the local junkyard and grab a fuel cap or two to fit your truck. Tear one apart, and figure out how the vent works.
You need to convert one into a non-vented adapter. Weld, glue, hammer shut, any and all vents. Drill a hole and attach whatever fitting makes life easy for you.
Make a gasket to go inside the cap so when its put on the filler tube, it gets a good seal.
Seal off the hose going to the canister that they sealed off. Mix yourself up a mix of dish-washing soap and water into a spray bottle.
Put the modified gas cap on and pressurize the tank.
DON'T go crazy here.
They use 1/2 psi.
The fuel system was not designed for high pressure.
If you are using a Schrader (tire) valve, just a quick shot with an air hose should do it.
Then, start spraying every rubber hose and tank fitting you can find.
When you see bubbles, you have found it.
But keep spraying, odds are you have more than one.
If you don't find it on the first try, odds are its so big that the pressure did not last.
Wet everything down with the soap again, and have someone watch while you give it another shot of air.
After checking to be sure the first shot has actually run out. Don't overpressurize the system.
J
I agree with this.
I'm glad I don't have to do this with my 74 because I KNOW where a PIA leak is on mine. It is the filler tube. A bracket that spot weld to the tube broke off and there is pin hole in the tube.
Also, before you start modifying a gas cap, Try pressure testing the lines individuality first. Cap one end and pressurize the line from the other end. You get may lucky here.
this is good advise. soapy water in a squirt bottle can be a very usefull tool!
DeviousK5
1/2 ton status
Did they provide a reason , Inoperative system or leaks? leaks can be a bitch to find but is the evap solenoid totally out of the question?they are simple to test.
rufusbooth
1/2 ton status
As far as I know they only check for leaks. No evap canister / solenoid test. Pressurize the system and see if it holds. Simple as that.
Soapy water and a SMALL amount of pressure in the system is your method of choice. Most likely a leak in the evap lines. Either a rusted out line or more likely a shot dry rotted rubber hose. You could always shotgun the evap system and replace all the rubber.
Rufus
Soapy water and a SMALL amount of pressure in the system is your method of choice. Most likely a leak in the evap lines. Either a rusted out line or more likely a shot dry rotted rubber hose. You could always shotgun the evap system and replace all the rubber.
Rufus
So, any luck?
