Quadrajet Q? again

[marq]

i got a real smoky idle on my q jet can anyone tell me why and how to fix it..........Marq p.s not the idle mixture screws

[cosmo]

Check that the accel pump needle valve is functioning properly.
Check also the well covers.
Cosmo

[marq]

well covers?and on my exploded diagram there aint nothin called a accel pump needle valve .What about float ?.......Marq

[jerry]

the well covers are in the center bottom of the main body. look like a coupleof folded over holes with a flat piece in them. a popular place for a q-jet to leak.

have sealed them with eoxy in the past.


jerry

[james]

Not to hijack your post, but do all q-jets have the same base? I'm using a olds 307 in my plymouth but want to ditch all the computer controls, which include the carb. Would a earlier chev qjet fit?

[marq]

you may well need an adapter to fit it because the bolt pattern is the old small rochester type pattern also the secondary flaps are huge about 2 1/4 inches wide each one so they do go down a bit into the intake.i managed to seal up the well plugs with leakfix which is for petrol tanks so that should do it no black smoke at the moment so it looks to be ok for the while .....Marq p.s adapters are available almost anywhere

[tommy]

Aren't the quadrajets the carbs with the phenolic floats that absorb fuel and get heavy over time? If the floats are black plastic, replace them. You can set the float level according to the instructions and it will still flood because the floats don't "float" like they used to. It used to be a common problem. I think they even made a scale to weigh your floats to see if they needed replacement.

[james]

the Olds has a q-jet, but it's computer controlled. Looking for a replacement.

[BELLM]

Normally when the well plugs leak they will drain the bowl overnight so you gotta crank it over enough to fill the bowl before it will start, unless you have an electric fuel pump. Epoxy works well, used to be able to buy a rubber plug that fit between the bowl and base that sealed the well plug area. Long time problem with Q-jets.

[DrJ]

[ QUOTE ]
Not to hijack your post, but do all q-jets have the same base? I'm using a olds 307 in my plymouth but want to ditch all the computer controls, which include the carb. Would a earlier chev qjet fit?

[/ QUOTE ]

They are all the same basic design but there are enough differences in the passages that the parts from different "smog" series carbs dont align or have compatible linkage. Just look for a carb that doesn't have a "1" at the begining of the ID number if you don't want a "smog" carb.

The smoking sounds like a sunk float. Replace it out of general principles. I prefer brass floats because you KNOW when they leak and have gas in them with a simple shake!

[marq]

I would love a new float trouble is can't get them over here..........Marq

[cosmo]

Then you ask a friendly HAMBer to get you one and ship it over there.
Paypal works fine for payment, and you will have the new float.
BTW, I might be mis-remembering the needle valve, but my mnaual says there is a passage vented to atmosphere to prevent fuel pull-over through the accelerator jets during high-vacuum events. Check that, too.
Cosmo