failed emmisions..help

[hutch]

i went to get my truck tested today and i failed the evaporative system part of the inspection. it passed everything else. any ideas of what could of cause the problem and tests i can do to figure out exactly what it is?

 

[Wicked_Sludge]

older trucks like to crack the fuel filler necks, thats where i'd start. also confirm your fuel cap has a good seal on it and check the vent lines running to the charcoal canister.

 

[hutch]

while i was there gettin it tested there was one line unplugged but i plugged it back in. all the other lines seem pretty good. i did have a body lift on the truck which i recently took off so im leaning towards the fuel filler neck.

 

[hutch]

well i checked the fuel filler neck and didn't notice any cracks or anything. i pulled the hose down a little bit to try and check the hole neck and still didn't notice anything. there are a couple little dents in it but no cracks or anything that i can see. any other suggestions? i checked the lines to the fuel vapor storage canister and they all seem fine. any ways to check those besides just by looks? any other ideas?

 

[Wicked_Sludge]

if you remove the line to the charcoal canister, you should be able to supply compressed air to the tank, then listen for leaks. keep the pressure low! no more than 2-3 PSI should be used!

 

[McCormack]

The easiest and cheapest place to start would be a new fuel tank cap - mine failed at my last inspection, and I replaced it with a new one - end of problem.

 

[hutch]

it passed the fuel cap test so its not that. tomorrow im gunna test some other stuff and see if i can track down atleast whats wrong with it. thanks tho

 

[hutch]

well i tested everything i could this morning and it all passed so i took it back to have it retested and it passed this time. they said the first time through that the emmision guy didn't hook up his stuff correctly and thats probably why it failed. it took them three chances this time to get it right. awesome emission people!

 

[Wicked_Sludge]

they must have some real rocket scientist working there eh?

glad you got your stickers.