Bronco not passing smog in Las Vegas nv

[74bronk]

Back ground info: I have a 302 with automatic trans and a 4 barrel Holley truck avenger. Had this same problem last year only I adjusted the jets down and it passed then afterwards turned them up to run better. This year I adjusted jets down again .... It didn't pass so I took it home again put a tach on motor checked the Rpm at idle about 700. Adjusted the jets down (so I thought) decided to try and adjust the floats In the bowl. not a good idea haven't touched them in years. I took it back up to see if it passed this time it was worse! Instead of 768 parts per million it jumped to 989 per. (Supposed to be bellow 700!) help im stuck need to get this fixed before the dec 22

 

[jckkys]

You may have to take it to a shop that has a 3 gas exhaust analyzer and pay them to set the idle mixture to pass.

 

[Whoaa]

When I was in Vegas and dealing w/ the polution regulations for my classic cars, I found a simple fix.

The local freindly shop close to my house, Big O tire shop on the S. Boulder Hwy in Henderson, we just stuck the probe into a modern car and got the numbers we wanted %)

 

[Broncobowsher]

You were not playing with the jets, you were playing with the idle mixture screws. You leaned it too much causing a lean misfire. You forgot to tell us what PPM the reading is, but it is pretty easy to figure you are dealing with HC. Need to richen the mixture screws to cure the lean misfire and high HC readings. But too much and the CO will go high. If you can't get them both in spec retard the timing a couple degrees. This will lower manifold vacuum, increasing cylinder pressure causing a better burn.

Really need to find a place with an exhaust analyzer. Really sucks to make a guess, pay for an emissions test, go back and make an adjustment and try again. Couple of failed tests eats a lot of time and money that could have been used to have someone dial it in correctly.

 

[Moon's74]

I live in Henderson and I take my bronco to Mr D's Fast Lane at Boulder Hwy and Basic. They have a gas analyzer and make proper adjustments. Will cost the shop time plus the smog but I've never had a fail and I have a mildly upgraded 302.

BTW, I started with the truck avenger also and never had good luck with it. Called Holley and traded to the 570 street avenger and never looked back and I've never had problems offroading...just a thought. The TA doesn't have an idle air circuit so getting the right tune for a smog is a b#$ch.

 

[kholding]

Another option: In Las Vegas, if you register it as a "classic vehicle" you don't have to have it smogged. The only restriction is that you cannot drive it more than 5000 miles a year. The only other downside for you is you cannot register it that way if it has failed an emission check within the last 90 days.

 

[73azbronco]

Might also consider putting on a stock two barrel carb to get it to pass.

 

[broncnaz]

Aside from adjusting the carb correctly. Turning the timing back to stock or even lower Might run like crap but will help it pass. Also have you done a recent tune up? ie change plugs, filters, oil ect? If your not running one already how about a 195 tstat and making sure the engine is at full temp before starting the test.

The Holley TA does have a idle air circuit pretty much every carb out there that is made for a engine that has to idle has a idle air circuit. So dont believe thepost that it doesnt have one as it does, couple that to the fact that a lot of people run theses carbs and do pass idle emissions.