Failed emissions

[bakerlaw67]

Just for background, my '87 K5 350 TBI was a purchase from a law enforcement auction for $750. It had been sitting since 2003, and possibly since 2001. Other than putting 2 used tires and a can of carb cleaner into it, I've done nothing. No rust, no dents, decent 4"lift, original black paint showing on frame. It runs and drives perfect (it needs a steering column) and it looks OK too.

So in order to get it registered, I have to complete (AZ) emissions testing. I didn't do any tuneup or finish cleaning the TB, because I thought that I could get a waiver if I failed, spent money, and failed again. It turns out the level is $450, so that was a bad decision that didn't matter. It passed the dyno/sniff with flying colors (K5/standard) 1.878/4.00 HC, 13.93/40.00 CO, 2.01/5.50 NOX. Even the gas cap test passed!

The problem is that it failed the "Pressure Test". They pinch the fuel tank vent at the charcoal can, and then pressurize the gas tank. Apparently there is an air leak somewhere. I'd prefer to dirty my own hands than pay for somebody else to. Does anybody have any suggestions of vacuum T's, connectors or anything else common to look at?

 

[K5ing in AZ]

replace the vacuum line going to the fuel tank

 

[pauly383]

There are several hoses on there to look at on your tank . You have a bare minimum of vent next the fill neck , fuel return for tbi , vapor can line , and fuel feed .

Its not uncommon to have something loose if the in tank pump has ever been replaced before .

BTW pretty Blazer ............... STAY AWAY FROM HERE IF YOU WANT TO KEEP IT THAT WAY

 

[bakerlaw67]

There are several hoses on there to look at on your tank . You have a bare minimum of vent next the fill neck , fuel return for tbi , vapor can line , and fuel feed .

Its not uncommon to have something loose if the in tank pump has ever been replaced before .

BTW pretty Blazer ............... STAY AWAY FROM HERE IF YOU WANT TO KEEP IT THAT WAY

Oh, it looks great from far, but far from great. The clear coat is flaking off, but it is straight and rust free. Is there a trick to getting around the skid plate or anything else I should know before I drop the tank?

 

[jarheadk5]

Wow... Gorgeous K5. With all the tube/chop/narrow that goes on here, it's hard to remember sometimes how good they can look - too bad mine is a straight-but-rusted-to-s**t example...

 

[bakerlaw67]

Wow... Gorgeous K5. With all the tube/chop/narrow that goes on here, it's hard to remember sometimes how good they can look - too bad mine is a straight-but-rusted-to-s**t example...

Nice Blazers/Burbs are a dime a dozen. Not too many short bed K's, but lots of DD 1/2 tons. That is one of the things I love about Phoenix. You see people driving late 60's early 70's C10 every day. Straight, rust free, paint burnt off or rollered on. I keep saying that I should just run rust free parts from here to Chicago. I'm sure I could make it worthwhile.

 

[pauly383]

Fortunately for me , mine has never needed dropping , my fuel pump is in the engine compartment where it belongs

I know the guy I sold my blinging pushbar to had the same problem with emissions , and his was broken nipple up top . He cut the floor and epoxied it back enough to pass .

Or so I heard