failed smog, evap leaving

[SalvagedB3000]

Hey guys, I got a 94 b3000. I went to smog today and I passed everything, but the fuel tank test. I guess somewhere along the line of my evap, there is a leak. I dont want to drop my gas tank just yet. I inspected some of the hoses and they seem ok. Anyone ever had this happen to them?

ANyone think it would be a good idea to shoot compressed air in there to see if i can hear a leak? I know they cant take a lot of pressure. Any ideas?

 

[MAKG]

BAD idea. It will turn failed smog into a failed fuel tank.

You can get quite far with a visual. If you really can't find it, a smog sniffer ought to find it. They can detect unburned hydrocarbons....

 

[SalvagedB3000]

Thanks,

I was also looking at the charcoal canister, and it has vented caps. Wouldnt that cause me to fail this test? I dont mean i took off the caps or anything, but the caps are vented vented from factory. Damn california smog laws!

 

[MAKG]

You DID NOT fail a smog test because of working-as-designed factory installed equipment. I guarantee it.

 

[SalvagedB3000]

Good point

Im going to go to my school and see if I can use the smoker that is used to test intake leaks. Any other ideas?

I noticed the charcoal canister is close tot he battery, and I have corrosion there. Hopefully the canister is not broken. I'll pulll that off and see if its ok

 

[SalvagedB3000]

A bad gas cap can also fail that part of the smog test. Get a new gas cap before you go back to the shop for a retest

I passed the gas cap test. The guy says its a new test to test the gas tank now. So he screwed an adapter on the filler neck. I guess it builds pressure and sees if its leaking.

 

[SalvagedB3000]

Thanks for the help guys. I went to my school and used the sniffer to see if there was anywhere with high hydrocarbons. Nothing went past 12 hc.

So we brought out the smoke tester. I took the hose from the canister and blew towards the gas tank. Nothing. So I tried it the opposite direction towards the canister. The smoke was coming out from the caps. My teacher was saying those vented caps should only allow air in and none out.

So I am hoping to fix that and see if my car might pass smog. Thanks again

 

[SalvagedB3000]

Ok, I went back to the smog station. The test is done by clogging the hose even before the charcoal canister! My leak is somewhere above my fuel tank

Is it easier to pull off the bed or just take out the tank?

I could get enough people to lift the bed off my truck, but pulling the tank doesnt seem too bad either.

 

[MAKG]

Many say that pulling the bed is easier, if it's an option.

You may want the dealer to deal with this. There was a safety recall on some fuel tanks around then, where the evap connector broke off, creating a potential fuel leak and fire/explosion hazard. It might be free....

 

[SalvagedB3000]

Many say that pulling the bed is easier, if it's an option.

You may want the dealer to deal with this. There was a safety recall on some fuel tanks around then, where the evap connector broke off, creating a potential fuel leak and fire/explosion hazard. It might be free....

Thanks, I called my local mazda dealer and he checked my VIN. He said according to my vin that recall isnt for my car. Doh!