V8 Chevette Daily Driver
- Thread starter jrm81bu
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That does sound like high float level. Also as said check the needle and seat. Does it look dirty inside? What mileage are you getting out of it?
It's possible it's the float. I never messed with it, although someone else has been into the carb before so... I've never been inside a quadrajet before any links or tips as to set it or even fully rebuild it. I've got the kit but was hoping to just get away with the top gasket lol.
Mileage sucks. I don't have a real accurate number yet but doesn't seem to be any better than maybe 15mpg. About the same as the Edelbrock that was on it. Maybe even worse.
Mileage sucks. I don't have a real accurate number yet but doesn't seem to be any better than maybe 15mpg. About the same as the Edelbrock that was on it. Maybe even worse.
Here's a decent tutorial on setting the float. Start at about the 3:40 mark.
http://www.youtube.com/watch?v=R1AFZtjb5i8
I don't know what your carb application originally was but 1/4" (give or take a sliver) is a good place to start. Your rebuild kit should have a sheet with the precise measurement. Since you have a kit already you might wanna swap in the new needle/seat assembly while you have the top off. Also make sure that the emulsion tubes are firmly seated in the top plate. These really aren't tough to rebuild so it might be worth taking it apart enough to do a full rebuild if you feel comfortable doing it. The biggest problem with Qjets is usually past modifications and improper rebuilds. If we assume (and maybe we shouldn't) that all the needles and jets are correct and haven't been changed, a proper rebuild will make it run fine. The only real wear point is the throttle shaft. If you go the full rebuild route, don't forget to epoxy the plugs on the underside of the main body and the one at the front of the fuel inlet.
http://www.youtube.com/watch?v=R1AFZtjb5i8
I don't know what your carb application originally was but 1/4" (give or take a sliver) is a good place to start. Your rebuild kit should have a sheet with the precise measurement. Since you have a kit already you might wanna swap in the new needle/seat assembly while you have the top off. Also make sure that the emulsion tubes are firmly seated in the top plate. These really aren't tough to rebuild so it might be worth taking it apart enough to do a full rebuild if you feel comfortable doing it. The biggest problem with Qjets is usually past modifications and improper rebuilds. If we assume (and maybe we shouldn't) that all the needles and jets are correct and haven't been changed, a proper rebuild will make it run fine. The only real wear point is the throttle shaft. If you go the full rebuild route, don't forget to epoxy the plugs on the underside of the main body and the one at the front of the fuel inlet.
Two easily missed things about Q-jets. The floats are prone to absorbing gas, so they "don't float", or at least not until the bowl is over-- full. The other is every time you remove the top of the carb, spread the float hold down pivot wire a bit. This gives the float a solid pivot, And makes the level adjustment you set ----what you actually get. Otherwise the fuel pressure make it dance higher.
Old Q jet guy.
Old Q jet guy.
What year carb? Is it off a 350? Do what is said above, rebuild it. Clean it out really good, blow out all passages with compressed air. Find out what primary jets and rods are in it.
Thanks for the input guys. I'll be sure to post what I end up with. And i'm unsure of the original application.
DRIVEN said:
Lol, sometimes I get a little carried away!
The real update is: I ended up with a third quadrajet that worked pretty good. Still same mileage. I'm figuring that a v8 turning 2600 is only gonna get so good of mileage without trying a lot of different rods. The friend that sold me the first one told me he'd give me my money back if I wanted it, so I took him up on it. I was putting his original top plate back on when the power piston popped up and I started looking at the rods. Both of them were bent 90* at the tip. I really don't think I did it when I originally swapped the top plates. But I pulled the rods out of the second parts carb and threw them in. I just had to try it out again, the leak was better and the mileage picked up. However my operating temps when up quite a bit as well, so i'm figuring it must be really lean. I went ahead and gave it back to the original owner and put the third qj back on.
Now the reason for the above pics is, i'm converting my dad's tbi truck to carb and i'm gonna use the intake and carb off from the Chevette to do it. I didn't need much convincing because i've been dying to put this Vortec top end on something. Since I had kinda given up on getting the best milage out the Chevette it became a good candidate. i really don't expect to loose much anyhow. Here's a pic of how it sits currently.
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