Runability issue. Minor. Question.

[D.PASSMORE]

Just throwing some thoughts out there. Your situation might be different. A friend has a cool set-up for checking for vacumn leaks. Modified a small propane plumbers torch kit. Cut the flame nozzle tip down and graffed a small rubber hose over the end of the nozzle and put a old screw out air blower nozzle on the end of thr hose. Screw valve onto little bottle, turns on the propane and adjusts the flow with the air nozzle. You can stick the nozzle in close to the carb or manifold. Beats the carb spray method.

[lyrikz]

Originally Posted by D.PASSMORE

Just throwing some thoughts out there. Your situation might be different. A friend has a cool set-up for checking for vacumn leaks. Modified a small propane plumbers torch kit. Cut the flame nozzle tip down and graffed a small rubber hose over the end of the nozzle and put a old screw out air blower nozzle on the end of thr hose. Screw valve onto little bottle, turns on the propane and adjusts the flow with the air nozzle. You can stick the nozzle in close to the carb or manifold. Beats the carb spray method.

Thats exactly what i have in my hand. Using it today.

[71gmcburb]

if you need any help i live in Everett and I could come over to give you a hand just pm me if you want

[lyrikz]

Originally Posted by D.PASSMORE

Just throwing some thoughts out there. Your situation might be different. A friend has a cool set-up for checking for vacumn leaks. Modified a small propane plumbers torch kit. Cut the flame nozzle tip down and graffed a small rubber hose over the end of the nozzle and put a old screw out air blower nozzle on the end of thr hose. Screw valve onto little bottle, turns on the propane and adjusts the flow with the air nozzle. You can stick the nozzle in close to the carb or manifold. Beats the carb spray method.

When i put the nozzle near the throttle linkage, the rpms smooth out.

I just dont get this thing. Once its warm, it just doesnt want to idle, and when restarting it takes just a tiny bit more to get it going.

Im lost with this thing. Plus not to mention i dont think the choke is set right.

[lyrikz]

Originally Posted by geezer#99

OK!!
Along the lines of D. Passmore's post. Maybe your metering rods are hanging up on the gasket. Runs lean cause they're stuck down in the jets.
Here's a link on quads. Lots of info.

http://www.digitalcorvettes.com/foru...ad.php?t=88376

Geez, quick question on the electric chokes. When you are setting those up you have the low cam and the high cam idle right?

so, to get on the high cam, you crack the throttle and you can lift it to the high cam. Now, when setting the electric choke, when its dead cold, do i want the electric choke to where it will put it on the high cam idle??? Im trying to read on how to set this and not a whole lot of info.

Also, i used the propane to find that there is a slight vacuum leak at the throttle shaft, but it appears like that is a normal amount. Im starting to have a feeling that its running out of fuel at idle. when you cover the carb, the idle pops up a bit, then starts to die out. So i dont think there is a vacuum leak, i think its just lean. those two screws in the front of the carb are for idlemixture correct??

[geezer#99]

When it's cold and you open the throttle if the choke is working right the choke plate closes off completely and the choke goes on the high idle cam. The choke pull off pot pulls the choke plate open enough to let it run. The amount of plate opening is adjustable by the screw above the black choke cover the power wire hooks to.
Try this.
Get the motor warmed up. Loosen the screws on the side of the black cover and turn it clockwise to the leanest setting. Lock it there. Make note of where it's set originally. It should have no choke working now. In your first pic after the video you have the secondary lock out highlighted in that red square. If the little tang is dropped off the rod then you know the choke isn't working.
See how it runs then.
THis way you eliminate the choke in your troubleshooting.
And yes the mixture screws are in the front at the bottom.
Can you take a pic of the carb from the top with the air cleaner off when cold and when warmed up running.

[lyrikz]

Originally Posted by geezer#99

When it's cold and you open the throttle if the choke is working right the choke plate closes off completely and the choke goes on the high idle cam. The choke pull off pot pulls the choke plate open enough to let it run. The amount of plate opening is adjustable by the screw above the black choke cover the power wire hooks to.
Try this.
Get the motor warmed up. Loosen the screws on the side of the black cover and turn it clockwise to the leanest setting. Lock it there. Make note of where it's set originally. It should have no choke working now. In your first pic after the video you have the secondary lock out highlighted in that red square. If the little tang is dropped off the rod then you know the choke isn't working.
See how it runs then.
THis way you eliminate the choke in your troubleshooting.
And yes the mixture screws are in the front at the bottom.
Can you take a pic of the carb from the top with the air cleaner off when cold and when warmed up running.

I had the truck fully warmed up and removed the electric choke. It still had the dying issue. Before i removed the electric choke i noticed when the truck was cold and you opened the throttle it wasnt putting it on the high cam. I pulled the choke off and when it was ice cold after sitting over night i marked it and then hooked up the choke to see if it was working and how far it moved. It is working and moved about 1.5 inch or so... So i just need to adjust that correctly and then see about this lean condition.

At work i have a gas analyzer. I can hook that up in the tail pipe and then get the vehicle warm and let it idle, that would tell me if its lean or rich correct??? I have an old timer there that knows carbs. Im just stubborn and want to figure this out myself. I sit and read all these articles and then just stare at the damn carb and some of it starts to make sense. lol.

[geezer#99]

Here's something to check. With engine off poke a small pencil (eraser end) into the vent hole in the top of the carb. End of pencil should contact metering rod hanger. You should be able to push the rods down and feel them come back up.
They could be stuck down causing a lean condition.

[lyrikz]

Originally Posted by geezer#99

Here's something to check. With engine off poke a small pencil (eraser end) into the vent hole in the top of the carb. End of pencil should contact metering rod hanger. You should be able to push the rods down and feel them come back up.
They could be stuck down causing a lean condition.

Your talking about the hole right on top right at the front correct? I lightly put a pencil in there and nothing moves in there at all. Nothing pushes down, nothing comes back up... What do you recommend doing now???

[geezer#99]

That's the vent hole. Metering rods could be stuck then. You could make a small hook out of a strong wire and pull them up.
I pm'd you my number.

[lyrikz]

Originally Posted by geezer#99

That's the vent hole. Metering rods could be stuck then. You could make a small hook out of a strong wire and pull them up.
I pm'd you my number.

Ya, nothing moved down there. Will i be able to grab on to the metering rod? I have no idea what they look like.

[geezer#99]

Get a good small flashlight and look down the hole. THe metering rods are attached to a hanger. Bend a sharp hook on a piece of hard wire. An old metal coat hanger is good to use. Pull up gently.
If it's hard to see down the hole use a small mirror with your flashlight aimed at the mirror. The light will reflect really nice into the hole if you angle it right.
In this link on page 2 the 4th pic shows what they look like from the top and how the gasket should look.

http://www.vetteprojects.com/kstyer/quadrajet.htm

[Wrenchbender Ret]

If there are no vacuum leaks, try enriching the idle jets. If that doesn't do it it is a good posibility the float level is too low.
I agree put the strongest return spring going forward pulling from the top of the lever. Then you can put a weaker spring pulling back.

[lyrikz]

Originally Posted by geezer#99

Get a good small flashlight and look down the hole. THe metering rods are attached to a hanger. Bend a sharp hook on a piece of hard wire. An old metal coat hanger is good to use. Pull up gently.
If it's hard to see down the hole use a small mirror with your flashlight aimed at the mirror. The light will reflect really nice into the hole if you angle it right.
In this link on page 2 the 4th pic shows what they look like from the top and how the gasket should look.

http://www.vetteprojects.com/kstyer/quadrajet.htm

ahhh, gotcha. Im going to go pick up a pos used quadra and tear it apart/put it back together, and then tear it apart again. If im going to keep this thing on my truck, i want to know how to fix it.

Or at least how things work.

So that metering rod should move up and down freely. So if it is stuck, i should take the top off and see why?? Or do they just occasionally get stuck?

[geezer#99]

Good idea on the carb for learning with. Get one thats the same as yours.
If you're tearing it apart take it off the motor. Couple small screws easily lost.
Metering rods should move easily. I had one that the rods hung up on the gasket occasionally. It can happen.
Buy a book like this.
Amazon.com: How to Rebuild and Modify Rochester...

[lyrikz]

Originally Posted by geezer#99

Good idea on the carb for learning with. Get one thats the same as yours.
If you're tearing it apart take it off the motor. Couple small screws easily lost.
Metering rods should move easily. I had one that the rods hung up on the gasket occasionally. It can happen.
Buy a book like this.
Amazon.com: How to Rebuild and Modify Rochester Quadrajet Carburetors (S-a Design) (9781932494181): Cliff Ruggles: Books

Quick question, when reading that article, it says "When the throttle is opened and vacuum drops, a spring raises the piston and rods. They lift out of the jets and richen up the fuel mixture.
"

So do i need to check when its running???

[geezer#99]

If you check it when it's running the rods will be pulled all the way down. When motor is off the rods should be up. Spring oushes them up. That's why I said you should be able to reach in the vent and push them down if they're not stuck in the down position.

[lyrikz]

Originally Posted by geezer#99

If you check it when it's running the rods will be pulled all the way down. When motor is off the rods should be up. Spring oushes them up. That's why I said you should be able to reach in the vent and push them down if they're not stuck in the down position.

THey are definetly stuck down then.

Will let you know in a bit.

[geezer#99]

Here's a pic for you if you end up getting another carb to practice on.
Even though it's a holley.
I use a long bolt with washers and nuts and chuck it into my vice and bolt the carb to it. Easier to work on and swivel if you need to. I'm using a wing nut on the top in this pic. Works the same.

[lyrikz]

Originally Posted by geezer#99

Here's a pic for you if you end up getting another carb to practice on.
Even though it's a holley.
I use a long bolt with washers and nuts and chuck it into my vice and bolt the carb to it. Easier to work on and swivel if you need to. I'm using a wing nut on the top in this pic. Works the same.

well, i took the hanger and fished around. I can definetly feel me pushing something down and it springing up. When i put the pencil in nothing moves. So i think something is blocking the pencil. But the smaller hanger touches and you can feel it move up and down freely... dang, hoping it was going to be that simple. lol.

So where do i look now. Actually, im going to go out and set up the choke, then run it till its warm and adjust the idle fuel mixture screws. See if fattening it up all the way does anything. If it doesnt, that means that my primaries jets are prolly to small, saying i do not have a vacuum leak which i dont think i have.

[lyrikz]

Originally Posted by lyrikz

well, i took the hanger and fished around. I can definetly feel me pushing something down and it springing up. When i put the pencil in nothing moves. So i think something is blocking the pencil. But the smaller hanger touches and you can feel it move up and down freely... dang, hoping it was going to be that simple. lol.

So where do i look now. Actually, im going to go out and set up the choke, then run it till its warm and adjust the idle fuel mixture screws. See if fattening it up all the way does anything. If it doesnt, that means that my primaries jets are prolly to small, saying i do not have a vacuum leak which i dont think i have.

well, i took it out, setup the choke, Thats dead nuts on now. Has a nice high cam idle, then after about 1 min, blip the throttle and it idles where it should. then you drive it till its 100% warm and it wants to start dying at idle.

when it restarts it starts up fairly easily, no black smoke. I turned out the fuel screws on the front about 2 turns and it smoothed the idle, but that was it. It still just wants to die at idle. Once you restart it, it idles decent for a min, then starts to want to die out again.

i did the cover the carb with my hand and the idle increases then wants to die out. so im sure there is no vacuum leak. I think i have a lean at idle condition. When i have the propane near it, it idles perfect. ahaha. But i obv cant drive with a propane bottle nozzle near the intake.. Everywhere else the truck drives FLAWLESS. It goes good, it cruises good, good response. Just no idle.

Thoughts???

[geezer#99]

Back to the drawing board!! You might need to pull the top off the carb and see how deep the rods are in the jets. They are adjustable. Maybe your mechanic adjusted them too deep.
What's your timing set at?
Sometimes we look at the carb as the problem when all along it's the distributor.

[D.PASSMORE]

Use that link that I provided. Download the first write up (document). Read it. Its rather en-lighting. I think that your getting close.
Two things that makes a gas motor run - fire and fuel. Kinda appears that its a fuel issue, if you don't have a timing problem -
Its not that difficult to work on a Q-Jet...
If you need another Q-Jet / I have a near NOS later model sitting on my work bench. I'm sure we could work something out...

David

[lyrikz]

Originally Posted by geezer#99

Back to the drawing board!! You might need to pull the top off the carb and see how deep the rods are in the jets. They are adjustable. Maybe your mechanic adjusted them too deep.
What's your timing set at?
Sometimes we look at the carb as the problem when all along it's the distributor.

Thats what my tech said. But why would choking off the carb cause it to idle better for a bit if it is the distributor??? IF i add more fuel to it at idle, the idle smooths out (propane). So if i was to richen up the primaries, i read you only want to go up 10% at a time. How the heck do you order jets?? I wouldnt be installing them, i think i will have my tech. do that.

What do i test to rule out the dist???? Timing is 16-18 degrees at idle, thats what my engine builder told me he wanted me to run.

Originally Posted by D.PASSMORE

Use that link that I provided. Download the first write up (document). Read it. Its rather en-lighting. I think that your getting close.
Two things that makes a gas motor run - fire and fuel. Kinda appears that its a fuel issue, if you don't have a timing problem -
Its not that difficult to work on a Q-Jet...
If you need another Q-Jet / I have a near NOS later model sitting on my work bench. I'm sure we could work something out...

David

Timing is 16-18 at idle. Thats what my engine builder said to run it at. I really think its running lean at idle. once the choke fully closes off is when im starting to get the ilding issues.. Im assuming when the choke is partially open as its warming up im getting a tad more fuel right?

Im open to all suggestions.

[geezer#99]

Is that 16-18 degrees with the vacuum advance line plugged off!!
You don't need to buy new jets. You can adjust the metering rods so they sit higher in the jets. It's called an APT. Adjustable part throttle. It's accessible under that round plug on the carb body just in front of the vent hole. Unfortuneately you need to pull the carb top off to get the plug out.