About my carb problems.

A warm engine with a partially closed choke plate will idle high.
Check to make sure the choke bi-metallic spring is getting power at the back of the alternator.

Where exactly is this spring? Is it actually mounted on the alternator because it does have a new one?

And by the way it does have a new fuel filter and what not.

Thanks,
Zac

Ok so I just went out and checked some things out. First of all the wire on the alternator was NOT there for the choke. I knew I had put this on before and I now just realized my mechanic took that wire off the alternator and plugged it into the carb heater plate. (They are the same type of connectors.) I didnt realize he had done this all I knew was the heater plate wasn't getting power and logically it appeared that that wire was the correct one. Anyways, I put it on and started the truck and it idled around 5-800 and kept dieing. So I went back to the carb adjustment screw that I had been tinkering with before and adjusted it a bit and now the truck runs fine. It was idling at 1500 when cold and when I blipped the gas dropped between 6-800 RPM. It is still idling rough but all in all good news.

Now what I need to know is what does the wire look like and where does it come from for the carb heater plate that the red wire plugs into?

Also, I want to try to adjust the idle so where exactly is it? Any pictures?

Thank you to all that have helped me so far...

Zac

* * * sigh * * *

Zac,

You are driving a truck that is what, 16 years old?
In a climate that experiences HUGE changes in temperature during the course of a year.

In those kinds of conditions, just like your windshield, the inside of your gas tank becomes a repository for humidity.

Where do you think the humidity (moisture) goes once it condenses?

I didn't say "assume that because your fuel filter is new, that it isn't clogged."

I said check it.

Remove it, and blow through it. into a clean container.

If the filter is on the fenderwell near the engine, it will take you less than a minute.

Humor me.

What does a test of this sort do?

It eliminates a fuel filter as a source of problems.

It is an unknown until it is tested, EVEN IF NEW.

If you read my thread on the 1986 that I fixed for the motorcycle shop guy, you will see that at least THREE filters were needed to trap all of the water that had condensed in that vehicle's gastank since 1986.

If you didn't check the old filter, before replacing it to verify presence or absence of water, then quite possibly water is now in your carburetor.

The presence of water will cause a number of symptoms you are experiencing.

Stumbling
Erratic idle
symptomatic "fuel starvation"

When you ask for help, you are supposed to do what the help asks you to do.

Instead of dismissing it with presumption.

If you find presence of water, the other suggestion of 2 cans of dry gas will cost you less than $3.00, and MAY prevent you from having to open up your carburetor to physically remove the water that may be located inside it.

Well when you had posted that I had literally replaced the fuel filter like 2 hours before so I thought it was fine.

So I pulled it off and blew thru it and some clear liquid came out but to me it just looked like gas. There was very little liquid that did come out btw. When I replaced it last time a brownish liquid also came out. (and quite a bit of it.)

Oh and also, the gas tank was replaced and completely flushed out and all so it shouldn't have been too bad.

Anyways, what do you think by that? Oh and coming out the "in" side of the filter was a small few drops of brown liquid.

I will probably just pick up another new filter tomorrow now that I know it can cause so many problems.

What do you think?

Does anyone know where the idle screw is or what wire to hook up the red carb heater wire too?

Oh and lastly, I cleaned and checked the EGR valve yesterday.

Thanks.
Zac

Well... I took it for another E-test today... Truck runs great.

It failed.

Again for the forth time. The emissions were actually worse than the last test this time. At idle it passed perfectly with excellent results but at 40km/h it failed, mainly in the CO2% area and failed ALOT worse then before. The mechanic (I decided to take your advice and went to a new mechanic) said he thinks it is something with the carb for sure and it looks like for some reason the carb is putting too much fuel into the motor, either a problem with what the computer is telling it from sensors or a problem with some of the electrical components of the carburetor.

I don't know what to do at all...

Zac

Sh-- man im going to send u the carb that came off ny 2200.It passed emissions here with flying colors.If that dont do it,roll that truck around back and put a round thru the radiator.BJ

ok, thanks for the update. . .I'm late to the discussion here, so I don't know everything that has been done to your truck.

Fixing your ride is eliminating possible problem causes, one at a time.

Brown blobby stuff is probably water and rust. Even the new filter showed evidence of it. Maybe some is in your carb. The motorcycle shop guy had LOTS. There isn't much to evicting it. Do you have 1/4" drive sockets, extensions, a 12mm wrench, a #2 phillips screwdriver?

What is your level of expertise?

Can you get a multimeter or other instrument that can measure dwell?
If you are going to pass emissions with a stock carburetor, you have to verify that the mixture control solenoid is operating in closed loop.

When you checked your EGR, how did you do that, and what were your results as you tested.

Can you post your test numbers from your emission tests?

I'm going to go back and try to get the history on your drivability issues in the meantime.

Hope this helps... BJ is going to send me his carb so thats my next step unless I do get this resolved..

Zac

Hi Zac . . .

Thanks for posting as much information as you did.

It is interesting that your 3rd test showed better numbers than the second or fourth.

Your high CO numbers indicate that your engine is running rich.

You might have a float level in your carburetor that is too high.

Sometimes they soak up fuel and get heavier, allowing more fuel into the bowl than is proper.

There are a couple of other things that your numbers indicate.

Maybe you have a choke plate that isn't fully open during testing.

If you keep a couple things in mind while you are working through your emission issues, you will be farther along than those who think more fuel is going to result in more power.

Fuel is hydro-carbon.
When it de-composes, the hydrogen combines with the catalyst (oxygen), and the carbon gets in the way.

Think nuclear fission, and lead control rods as an analogy.

Too much fuel in relation to air = slow burn = excess hydrocarbon left over.
Too much air (oxygen) = incomplete burn, as not enough hydrogen is present to pass the fire=excess hydrocarbon left over " + " really low CO, as the excess air (oxygen) mixes with the CO presented during the burn.

This isn't rocket science, but we are burning rocket fuel, sort of.

So one thing you can do while you are waiting patiently for your fuel mixing chamber from kind Mr. BJ is assemble the tools we talked about, as you are going to be removing your carburetor either to fix it or replace it.

In the meantime, I am going to give you some things to check, because you may decide to educate yourself and repair your carburetor since you may have the luxury of having a second unit available so your truck isn't disabled.

I am curious why your third test posted so much better numbers . . .
Had you gotten the test at a different location, or was it warmed up more, like just coming off a freeway or something.

These trucks need to be fully warmed up at testing. You can't shut them off at the test center while you are waiting your turn in line. It's probably a really good idea to keep the converter hot by running the engine at 1500 RPM while waiting your turn.

Obvious things, like sparkplugs, wires and other ignition components need to be working properly. Air filter not clogged.

If you have a vacuum pump, please verify that your distributor vacuum advance is working properly. Late ignition timing might be all that is occurring during your testing. A late spark doesn't give the fuel enough time to burn.

Because your idle readings are really good in all of your tests, I think you might need to look at both centrifical and vacuum advance in your distributor.

Check for a vacuum signal at the distributor.
Maybe the line is not connected to the base of the carburetor.
When you rev the engine, you should have a really strong pull at the distributor end of the hose.

You might want to pull the distributor cap and verify that a vacuum signal at the advance pulls the ignitor plate about 15 degrees, then snaps back at vacuum release.

If you take the air cleaner off, while standing at the front of the truck, the port for the distributor vacuum signal is at the bottom of the carburetor, and at about the 7:30 position, if you look straight down at the carburetor.

While you have the air cleaner assembly off, you can ascertain fuel level inside of the carburetor by taking a really strong flashlight, and shine it into the sight glass located on the front of the carburetor, facing the radiator.

It might be hard to see the fuel level, but is should be about halfway up the glass. If the truck is running, you will see it maybe a little easier.

You might have to use a rag to clean off the glass to see through it.

Does your carburetor still have a roll pin covering the two big holes on the same side you showed in your picture of your idle screw? I couldn't tell from the picture. If it is in place, leave it alone for now. There are a lot of stupid ways to break a carburetor trying to remove the pin the wrong way.

Enough for now.