QJet Adjustments

[irishman999]

My first question is, Do you see alot of black smoke when you mash on it? The Quadrajet is vacuum operated so it should not be dumping gasoline unless you have enough vacuum to open the secondaries. Is your carb the original one on your truck?

[Mattman2010]

Originally Posted by irishman999

Try adjusting that bad boy, when you stomp on the gas it pushes that rod down and squirts it in your carb. There is two holes the rod could go in, You can also bend the end of the stamped metal rod according to the how to guides I have read.

It was in the closer hole, and I moved that to the farther hole and it doesnt seem to have made a difference.

Originally Posted by irishman999

My first question is, Do you see alot of black smoke when you mash on it? The Quadrajet is vacuum operated so it should not be dumping gasoline unless you have enough vacuum to open the secondaries. Is your carb the original one on your truck?

I know my engine is burning oil, so at start up there is some black smoke. At times I think that there is some black smoke but it just isn't enough to really tell. The secondaries are just floating, they do not have that vacuum operated linkage hooked up to them. The PO took it off because he said that they go bad and it works without it. I have the vacuum thing, but I do not have the actual linkage that goes between that and the secondaries. Could this be the problem?

The carb is the original one to the truck that I know of. I pulled this engine and carb out of a K20 that was all rusted, and put it in my k10.

[tucsonjwt]

When your truck is warmed up, remove the air cleaner and operate the throttle to simulate condition you describe above. On two of my squares, the Qjets had a sticky choke valve, causing the engine to bog and consume a lot of gas. These choke valves and associated linkage have a tendency to carbon up and stick. I had an Edelbrock that had a choke valve that was manufactured slightly too big for the opening in the carb - I had to remove the valve and file it off slightly - then the choke would never close off completely and caused hard cold starts. I would try a spray can of gumout to clean the carb when it is warmed up.l

[irishman999]

Originally Posted by Mattman2010

It was in the closer hole, and I moved that to the farther hole and it doesnt seem to have made a difference.



I know my engine is burning oil, so at start up there is some black smoke. At times I think that there is some black smoke but it just isn't enough to really tell. The secondaries are just floating, they do not have that vacuum operated linkage hooked up to them. The PO took it off because he said that they go bad and it works without it. I have the vacuum thing, but I do not have the actual linkage that goes between that and the secondaries. Could this be the problem?

The carb is the original one to the truck that I know of. I pulled this engine and carb out of a K20 that was all rusted, and put it in my k10.

If its burning oil the smoke should be a white/blue color, black=rich. Try connecting that vacuum pull off, That will keep the secondaries from flapping open before the vacuum condition is right.

When those secondaries open it pulls some needles out of the big secondary jets that dump fuel down your carburator.

I have to warn you that this is my theory, I am not an expert and there is most likely 100's of people here who are experts.

[Mattman2010]

Originally Posted by irishman999

If its burning oil the smoke should be a white/blue color, black=rich. Try connecting that vacuum pull off, That will keep the secondaries from flapping open before the vacuum condition is right.

When those secondaries open it pulls some needles out of the big secondary jets that dump fuel down your carburator.

I have to warn you that this is my theory, I am not an expert and there is most likely 100's of people here who are experts.

Yeah after I said that I was talking to my dad he said oil is blue, water is white, and rich is black. When I floor it i do get black smoke, so it is getting to much fuel at full throttle. The vacuum thing would be a simple fix, but I am missing the linkage that goes from the vacuum to the secondaries and I am not sure where to get that from.

[irishman999]

Originally Posted by Mattman2010

Yeah after I said that I was talking to my dad he said oil is blue, water is white, and rich is black. When I floor it i do get black smoke, so it is getting to much fuel at full throttle. The vacuum thing would be a simple fix, but I am missing the linkage that goes from the vacuum to the secondaries and I am not sure where to get that from.

Go to a pick-n-pull, Im sure there is at least one qjet you could snag the linkage and vacuum part off of.