Rochester Q-jet Carb

>>17285907
its too rich

what did you do to the car so far?

>>17285924
i drive is carefully. I cant slam the throttle to open the second air doors or else it backfires

>>17285924
Also I havent done anything to it.

>>17285966
Good luck.
Quadrajunks suck.
Too many options on that pos for what's wrong.
Find a classic Chevy forum.

>>17286324
gee, thanks..

have you considered a rebuild kit

Sounds like it's too lean, but I'm not very familiar with the metering circuit on the Qjet as I am more of a ford guy.

Put an autolite 4100 on there and all your problems will go away.

>>17286400
Just being real man.
Too complicated for no reason.
Look at how many moving parts are in a holley for comparison.
Not even going to mention metering rods.
It takes very little to get a quad out of tune.

How clean does it look!? As in, when was the last time it was opened up.
Are you running ethanol (e85 type crap) in it? It will eat the rubber components.
Does/has it sat for periods longer than a week? This can cause fuel to evaporate and leave deposits that will clog orifices.

>>17286576
4100's are square bore, his is spread bore.
Using an adapter plate is ghetto.
He can get an edelbrock (still has metering rods but overall a better design) or a holley in spreadbore.
But spending $400 for a new carb that will cause as many tuning issues is pointless.

>>17286623
OP here, not looking to waste money on after market carbs. My carb was rebuilt in late 2015 and has been good ever since till now.

>>17285907
Check timing

>>17286769
You won't be able to fix anything until your learn about the q-junk.
You probably have a torn diaphragm or gunked-up metering rod.
Metering rods are a pita to assemble. If they're not lined up you can bend them if you torque down the cover like an idiot.
Chances are you can pop the top plate off without damaging the gasket.
If theres a white residue in the bottom of the float bowl (the large chamber that fills with fuel) then you need to take the whole thing apart- chances are passages are clogged.
Just get a rebuild kit at the local auto parts store for $40 and start digging in.
If you're careful, you want have to adjust anything if there's a damaged diaphram- just replace and reassemble.

OP here, it drive okay at a moderate speed on highway but I cant open the throttle too fast or too much without it spitting like a camel. It idles and starts ok in the morning.