305 Carb/Emissions issues

[kdubaz]

First let me go on the record as saying that if you want suspension work, bodywork, custom fabrication, I'm the guy.

With motors, I don't know crap. Seriously.

The truck I'm hoping to turn into a daily is an '81 Fullsize that had a 305 implanted in it at one point or another. Truck runs great, needs valve seals but nothing too major.

First time out it flew off the charts for emissions. I changed the oil, plugs (were fouled) fuel filter, adjusted the carb which was WAY out, checked the timing and I was good.

That time I only blew twice above the legal limit.

I work with a lot of mechanics, so I checked with them and the general thought is that the float is screwed up and the carb needs to be rebuilt. I can't find anyone in town to touch it for less than $400, and for that I can get a new intake manifold and 4-barrel.

So the question I guess, is if anyone knows of a good carb shop in Phoenix, or if it's possible for me to pass emissions with a 4-barrel at all. Anyone have experience in AZ testing?

[PHOENIX]

Does your truck have an A.I.R. Pump?
The pump is located under the alternator and pumps are into the exhaust manifolds. The fresh air gets burned with the hot gases resulting in cleaner emissions.
Picture 1 (pump itself)
Picture 2 (on engine)
Picture 3 (apart)
Picture 4 (apart)
Picture 5 (apart)
Picture 6 (apart)

Does your truck have a catalytic converter?
This will be on the exhuast pipe right after the y-pipe (if you have one).
It is usually right under the drivers seat. There is also a heat shield there because the cat gets very hot.

Do you have an EGR valve?
This is located on the passenger side of the intake manifold near the back of the carb.
Picture 1 (not exact, but similar)
Picture 2 (on engine, gold thing under aircleaner)

The components above if working properly will make a big difference in the emissions output. Usually they will fail (visual inspection) you for not having these. A vapor canister (behind drivers headlight, PICTURE HERE) is also required (if your truck originally came with one).

I had this guy rebuild my carb (Edelbrock 1904, 4 brl q-jet).
Carburetor Specialties
3137 W Virginia Ave
Suite 10
Phoenix, Arizona 85009
I believe the owners name is Kevin. He is very knowledgable and was very fair with his pricing. I thought I had another problem with the carb just after he worked on it and he rechecked the entire thing in and out and upgraded one part for no additional charge. I would use him again. His turn around was a couple days. He only works on loose carbs though, no on vehicle work here. When I called around for carb rebuild the going rate was $100-300. I dont have the receipt in front of me but I believe I paid $130 for the rebuild (parts and labor).
How did you adjust your carb (please explain the method)?
What is your timing and RPM at idle?
Do you know what your total timing advance is?
POST YOUR EMISSIONS RESULTS SO WE CAN SEE WHAT YOU ARE FAILING.

WHATEVER YOU DO, STAY AWAY FROM LOPERS PERFORMANCE CENTER.
THEY DIDN'T DO ANYTHING I PAID THEM FOR AND EVEN TRIED TO THREATEN ME WHEN I DEMANDED MY MONEY BACK FOR THE ILLEGAL MODIFICATION THEY MADE TO MY EMISSIONS SYSTEM.

Click here for ADEQ website.
What emissions test location did you go to?

The emissions test facilities around here are a joke.
I have had the best luck at this location:
10210 N. 23rd Ave., Phoenix, AZ 85021
Ill take a test at one and fail (by quiet a bit), then a few days later (with nothing changed, not even fuel) go to a different location and pass with flying colors.
They don't know how to drive manual transmission and it really pisses me off.
I have to go in September, I sure hope I pass I hate this emissions crap.

Here are my emissions test results I had on here from before.
Notice the change in standards and readings between tests:

Oct. 1999 (New Engine):
It is a reinspection because they failed me for missing a vacuum line.
They didnt believe the results so 3 guys looked over my truck for 15 minutes until they found a missing vacuum line and failed me. I fixed it and passed.


May 2002:


Oct. 2004 (Failed):


Late 2004 (Failed):


Carbon Monoxide (CO):
Carbon monoxide emissions are the result of an incorrect air/fuel mixture. In a carbureted vehicle, improperly working floats, power circuit and choke circuit could cause high CO. In fuel injected vehicles, improperly working injectors, pressure regulators, coolant sensors or MAP/MAF sensors could all contribute to high CO emissions. Some other common systems or components related to CO emissions are the air filter, PCV system, canister purge, O2 sensor and air Injection system. Due to the complexity of the internal combustion engines, there may be layered problems related to high CO emissions.

Hydrocarbons (HC):
Some common causes of high hydrocarbon emissions include improper ignition timing, vacuum leaks, engine mechanical problems and malfunction of components related to the ignition system, such as spark plugs, secondary wiring, distributor (if equipped) and coil. Due to the complexity of the internal combustion engine, other components may cause high HC as well.

Nitrogen Oxides (NOx):
Nitrogen Oxides in vehicles are caused by excessive combustion chamber temperatures. Some of the common causes of high NOx emissions are problems with the vehicle's Exhaust Gas Recirculation System (EGR), improper ignition timing, lean air/fuel mixture and malfunctions in systems that control engine temperature, such as the thermostat and cooling fan, and vacuum leaks. Due to the complexity of the internal combustion engine, other components may cause high NOx as well.

[PHOENIX]

Here was the last test I took:
Please tell me the standards have not been lowered again.

Jan. 2005:
Notice the test was only 16 seconds long.
BTW nothing changed in the vehicle between the late 2004 test and this one (just location and fuel):

[kdubaz]

After work I'll put up all the test results here, as well as the answers to those questions. Thanks!

[Eyegore]

I called a place on Mcdowell Road and about 25th Avenue, Bob Reams, if I recall i as quoated $260, takes one day. 602.272.6474
Also there is another I just heard of, 7th street n/o dunlap but I cannot find the name or telephone # sorry.

Tom

[kdubaz]

I'll go ahead and answer your questions.

Originally Posted by PHOENIX

Does your truck have an A.I.R. Pump?

No, it does not have an air pump. Just checked.

Originally Posted by PHOENIX

Does your truck have a catalytic converter?

Sure does. Just went to Mighty Muf'ler the day before the test and got one put on.

Originally Posted by PHOENIX

Do you have an EGR valve?

I sure do, and it's connected.

Originally Posted by PHOENIX

Usually they will fail (visual inspection) you for not having these. A vapor canister (behind drivers headlight, PICTURE HERE) is also required (if your truck originally came with one).

Mine does have one, and it's connected.

Originally Posted by PHOENIX

How did you adjust your carb (please explain the method)?
What is your timing and RPM at idle?
Do you know what your total timing advance is?
POST YOUR EMISSIONS RESULTS SO WE CAN SEE WHAT YOU ARE FAILING.

I had one of the techs at work adjust the carb by tightening in the two screws that are towards the front of the carb. It was set so rich you could smell it all over.

RPM - no tach. However the timing is at 10 deg.

Emissions results:

First test:
Gas cap - pass
HC - 8.08
CO - 147
NOX - 1.66

After doing the adjustments I posted about, I pulled the following:

HC - 6.79
CO - 98.91

I'm closer, but still ridiculously high.

Also the guys at the show claimed that the cat needed to be broken in and if I took it back on Monday (it was Friday) after driving it, I'd pass. Frankly, I doubt that, I still think it's dumping fuel.

Originally Posted by PHOENIX

What emissions test location did you go to?

North Scottsdale, right up the street from my house. The guys there have been really cool about the truck, even having different people test it to try to get it by.

I can always give that rebuilder a call, but am I on the right track?

[PHOENIX]

On the Q-Jet style carbs the bottom plugs can leak unless sealed correctly.
A professional carb rebuilder will do it correctly without being asked.
This is a typical problem with these carbs.

You could be getting additional fuel into the mix that you cannot control because of this leak. If you really suspect the carb as being the problem, I say get it rebuilt and try the test again. There could be a few problems with your carb if it is older and hasnt been rebuilt in the last 6-years or so. The fuel ("Phoenix Blend") we get out here can be rough on carbs.

If you still have the under the hood emission label see if it shows the AIR pump in the diagram. If it does and you dont have that they can technically fail you. Does your manifolds have the injection tubes or ports on them?
If your truck has headers maybe the previous owner removed these components because they can be a PITA when doing new exhuast system.
I would believe you should still be able to pass without the AIR pump system.

I would also bump the timing back a bit.
Try 6 deg. for the test, then put it back to where you like it.
You may need to adjust the idle speed after the timing adjustment.

The cat does need to be hot to work correctly.
Make sure the truck is fully warmed up before you get it tested.
The emissions components are designed to work when everything is heated up.

[kdubaz]

Ok, an update.

I followed your advice Phoenix, and I took it down to Kevin at Carb Specialties who cleaned up the carb and got it running smoother.

Kinda.

Well I hooked it back up, and right out of the bat it wasn't running right. I ended up advancing the idle a bit, and that worked out for a bit, but then I backed it off and adjusted the screws at the bottom of the carb and it ran well enough for me to bring it to work.

All the way to work, when I'd give it a bit more gas, the truck would kinda stall a bit and whistle while accellerating. When I one of my techs at the shop took a peek, he saw that the fuel filter line was loose, so we connected that, but the truck won't idle down. He feels that the throttle plate may be sticking and that's causing the problem.

Also had a little fire under the hood too. That was a bit scary.

Right now I'm pretty concerned about this, because I need to not only get home today but I wanted to get it through emissions. What kind of options do I have here?

[84 400]

man i know were you are at i just failed for no3's by a .2. my truck had the air pum and egr off it when i got it so how can i put the system back. were do i start, and what all do i need (just the egr and the air pump or is the whole mess needed.

[kdubaz]

Yeah, honestly I'm considering just taking it to a shop because I need this thing running by Saturday next week.