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Failed emissions testing

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,872
Rustytruck-

It is a 1.8 The jets are 52 so i just ordered 46 and 48 size jets.

Unfortunatly the previous owner had put a 2100 carb on this and the stock should be a 2150 in the research I have found. So I was not able to spend the money and find a true motorcraft 2150 at that time. So i went with what I could get.

yes the butterfly does what it should I believe I have all of that set up correctly.
Yes the bronco was fully warmed up and was never shut off until the inspector shut it off after the test.

I am trying to get it back to "stock" but as I mentioned the previous owner ripped it all out and some of these parts are not manufactured any more. 1975 is the only year with and electrical connection on the PVS. Took my many months to figure this out as others bronco owners that have not had a 75 did not even know this. So it has been a long and slow discovery and I just tackle the next problem as I get to it. I will start with the Carb and see how I can get that to help and I will continue to play with timing.
Some people seem to think it is easy for a bronco to pass others have stories of going in 2- 3 times to get it done.

this happens because of lack of exhaust analyzer so you don't know where its at going in. just a 1/4 turn off on one idle screw can throw it off enough to fail. when I tune mine i use a manifold vacuum gauge and adjust the needle for the highest steady vacuum reading and then re adjust the idle level to get 700 rpm in gear on my automatic and re adjust the screws again until the screws are adjusted right and the idle speed is right. if the vacuum needle is not steady you wont pass. check the vacuum diaphragm on the distributor and any other sources of vacuum leaks. idle adjustment covering up vacuum leaks will cause a fail too.
 

Kalex

Contributor
Full Member
Joined
Mar 29, 2007
Messages
244
Loc.
Novato, CA
You may have gone so far with your effort, time, and money spent that you want to see this through to completion, but if you get fed up with trying to get it to pass you could look into registering it in another state that doesn't have such requirements. Some states you don't even need an address or to own property. Vermont comes to mind.

Yes, technically the vehicle in question is supposed to reside in that state for 181-183 or so days a year, but who really tracks that. :)


My neighbor has his old truck with a Vermont tag and is in CA. He doesn't even run the front plate because most don't know or care that Vermont requires a front plate. Just thinking outside the proverbial box.
 

EPB72

Contributor
Bronco Guru
Joined
Jul 13, 2019
Messages
1,209
Loc.
Pleasant Hill, CA
FYI ,,these are post catalytic convertor readings if cat is working then the numbers he posted could be much higher then indicated on the smog printout,,using a gas analyzer to tune you need to probe precatalyst to get true readings unless your using a 5 gas analyzer and are able to use lambda calculations..

making some tweaks to see if theres an improvement fine,,,,But having a bouncy needle on the vacuum gauge at idle with it leaned a bit ,with low compression on a cylinder ..A leak down test seems the most logical at this point...
 

AZ69EB

Sr. Member
Joined
Jun 8, 2006
Messages
680
GWS34 - many people in the bronco community put historical plates on our bronco’s. This will exempt you from the emission test. Then the limitation is typically insurance policy that allows you to use your bronco daily.

I and many people purchased the insurance policy that allows us to use the bronco on and off-road. I will share the information with you. Send me a PM.
 

56f100bbw

Contributor
Bronco Guru
Joined
Feb 3, 2008
Messages
2,406
Loc.
Tucson / lakeside AZ
On my 76 bronco they used to torture me back in 2005 On emissions got tired of it registered in the White Mountains AZ all good now
 

73azbronco

Contributor
Bronco Guru
Joined
Nov 11, 2007
Messages
8,778
Take it to the guy in Glendale, easy peasy. Don't be the guy violating the law registering in another state you don't live in.
 
OP
OP
G

gws34

Jr. Member
Joined
Jan 29, 2005
Messages
128
this happens because of lack of exhaust analyzer so you don't know where its at going in. just a 1/4 turn off on one idle screw can throw it off enough to fail. when I tune mine i use a manifold vacuum gauge and adjust the needle for the highest steady vacuum reading and then re adjust the idle level to get 700 rpm in gear on my automatic and re adjust the screws again until the screws are adjusted right and the idle speed is right. if the vacuum needle is not steady you wont pass. check the vacuum diaphragm on the distributor and any other sources of vacuum leaks. idle adjustment covering up vacuum leaks will cause a fail too.

I did use a vacuum guage and got the needle steady at 18, then with timing light set rpm at 550 idle and set the advance to 6 btdc. Reconnected the vacuum advance tube and double check vacuum again. adjust and then reconfirm all are where they need, vacuum, 550 rpm at idle and 6btdc. That is where I thought I had it set up. I am hoping the new jets will allow me to lean out the mix more than it is now(or in essence create a leaner mix with smaller jets).
I believe there are no vacuum leeks, I have replaced every single part and hose. I have used the trick to spray and see if the engine surges or stalls to show a vacuum leak.
 

JefeAZ

Bronco Guru
Joined
Aug 23, 2011
Messages
3,088
Loc.
Tucson
What insurance do you have on it? I can set you up with a Hagerty policy that will waive emissions for life
 

JefeAZ

Bronco Guru
Joined
Aug 23, 2011
Messages
3,088
Loc.
Tucson
What is the mileage limit per year with that insurance?
I think the most I've requested is 3,500 but they have never asked for proof or verification that you stay under that. They are just trying to weed out the people who are trying to insure daily drivers. Hagerty only does secondary/pleasure use vehicles.

Im leaving the office but PM me if you want to check on rates. I can get it issued in minutes and you take the proof of insurance to DMV. Once they see collector insurance on the coverage page they waive emissions and give you the new reg
 

No Hay

Bronco Guru
Joined
Jun 4, 2014
Messages
1,657
I think the most I've requested is 3,500 but they have never asked for proof or verification that you stay under that. They are just trying to weed out the people who are trying to insure daily drivers. Hagerty only does secondary/pleasure use vehicles.

Im leaving the office but PM me if you want to check on rates. I can get it issued in minutes and you take the proof of insurance to DMV. Once they see collector insurance on the coverage page they waive emissions and give you the new reg

That's what I did when retiring here from Portland. It was quick and easy. Highly recommend!
 

broncogt

Jr. Member
Joined
Mar 1, 2010
Messages
93
Check for vac leaks. Test every diaphragm (dist vac advance, EGR, trans modulator, air pump backfire valve).

How is your front balancer? At one point the outer part of mine spun. (timing marks are on the outer part) No way to tell what it was timed.

I have had pretty good luck with a tune that passes and runs ok too. Always seems like it runs better a little rich on idle mix.

I plan on going the Hagerty route too.....
 

jckkys

Contributor
Bronco Guru
Joined
Mar 15, 2012
Messages
5,221
I've been fighting the Pima Co. Az. emissions since about 1980. At first, I went to the test and of course failed. Then I went to one of the emissions shops to get charged 50 bucks and a bunch of vacuum leaks. Then I passed and went back to the emission shop to get the truck running again. By then I knew the whole thing was a joke. Later, a friend with a shop and a 3 gas analyzer let me play. I found you can lean the mixture and the CO goes down and hydrocarbons go up. At one point both are low enough to pass. Without the analyzer, it's hard to tell the desired A/F ratio. The sleazy shops just speed up the curb idle to about 1200 RPM and pull hoses to create vacuum leaks. By now the engine is shaking, but will pass. What a scam. They don't even try to find the A/F ratio sweet spot. You need an honest shop that makes an effort to do it right.
The emissions check stations don't know exactly what you're supposed to have. I pulled the air pump on one EB and changed the alt. bracket. They didn't notice, but when I previously simply left the belt off I failed for equipment on the same truck. My '77 never had air injection from the factory. They never mentioned it. I'm sure EGR and cats. are the same. If it looks like it's there and hooked up you're OK.
Your results look to be mostly idle related. Different jets won't help that.
 

ntsqd

heratic car camper
Joined
Jan 30, 2005
Messages
5,953
Loc.
Upper SoKA
As was posted, it takes a 3 gas analyzer to beat a 3 gas analyzer. Find a good tuning shop that can dial it in.

One thing that I was told about getting my '84 yota to pass, get the cat hot before taking it in. As in drive at highway speeds for some distance before going to get it tested. When you get to the test place DO NOT turn the engine off and try to get it tested ASAP. Smog guy even commented once when it was a new cat that he could "smell that new cat smell."

Does AZ allow for upgrades, i.e. can you do a complete SEFI conversion legally?
 

AZ69EB

Sr. Member
Joined
Jun 8, 2006
Messages
680
. can you do a complete SEFI conversion legally?

Yes. The emissions locations are sub-contracted. Most employees are clueless. Tailpipe sniffer. I went from carter carb that I had a ritual of detuning to switching over to 93 mass air efi. I never looked back and never had an issue with trying to past the emissions test again.

Then I changed my bronco to history/ classic car plates and insurance. Your vehicle becomes emissions exempt at that point. I now purchase tags that last 5 years.
 
OP
OP
G

gws34

Jr. Member
Joined
Jan 29, 2005
Messages
128
Thank you all for your help. I want to use this as a daily driver, so that is where Hagerty's wont help. I believe if I am going to own this I want to use it, not just look at it in the garage, Sorry not trying to offend those who do.

I will keep everyone updated as I progress.

Thanks
 

tirewater

Bronco Guru
Joined
Jan 28, 2011
Messages
1,046
Loc.
San Francisco Bay Area
You're almost there!

Drop your main jet down to #48.
Verify that your EGR valve is opening correctly within the parameters. Is it connected to port vacuum? Is the PVS opening properly?

Check for any vacuum leaks at the carb base plate & EGR connection.

After setting your main jet. Set timing to 8-10 degrees, and set the idle mixture using the vacuum gauge. Once you have relatively smooth vacuum, turn the screws in a 1/2 turn. Ignore the 'timing to low' zone on the vacuum gauge (if it has one).

The truck should run fine (unless you have an outrageous cam).

Speaking of, stock cam?

The test results were as follows
HC- loaded reading 222 - loaded standard 250 - PASSED
HC - idle reading 429 - idle standard 250 - FAILED
CO - loaded reading 6.47 - loaded standard 1.50 - FAILED
CO - idle reading 6.46 - idle standard 2.00 FAILED
 
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