Camaro 69

If tripping the fast idle linkage doesn't do it, check to make sure your timing isn't too far advanced.

stop the rust

I had the same thing, it's because there's an idle bypass air bleed through the main body and through the base plate on some models suited to larger engines or engines with low vacuum signal. It's enough air for my six cylinder to run with the throttle plates completely shut. I blocked mine with screws and regained idle control. This does not apply to all Quadrajets and the air bleed location depends on the model of carby. If your going to mess with this you will need the Quadrajet book by Cliff Ruggles. I have also posted a video about air leaks from a warped air horn.
Quadrajet air leak fix and warped air horn repair. - YouTube

clintsy

Thanks for the info, that definitely helps.
A couple things happened this past month so I haven't been posting here lately.
My oil smelled like gas so I pulled the Carb and found the needle and seat assembly was messed up and not seating when the float bowl is full.
I found a couple extra qjets and rebuild kits my dad left me so I rebuilt an extra 86 e4me from a olds or buick, put that on and it runs a lot better but I still have that slight hiss.
I actually put a "warped airhorn" to fuel bowl gasket on that's pretty thick.
The idle is in check now, 750 in drive and it doesn't stumble like the other 83 carb
Ill take a look at the air bleed this afternoon and see if that's the problem, thanks again

kevinkpk

I think getting rid of the holley is the fix. Explain this hiss.

clintsy

I actually ditched the Holley remanned qjet and found a 86 qjet in my garage, it was a hot air choke but I switched it to electric and it had the front inlet so I grabbed a banjo inlet, and I put a rebuild kit on.

The hissing noise kinda sounds like a whistle, when I hit the gas slightly it doesn't whistle as loud. It was the same on both carbs, the kit had a matching base gasket that was on the old carb so I'm starting to think the base gasket may be wrong.

I asked cliff about this and he also said check out the air bleed

Thanks for the help,
Clint

kevinkpk

How thick is the base mounting gasket? How much torque did you put on the carb?

clintsy

The gasket is 1/4 of an inch, I don't have a torque wrench but when I tightened the bolts I did it in a x pattern until lightly seated then 1 turn or so. I didn't tighten the crap out of it or anything

kevinkpk

Ok, usually if it is a gasket, either seperated or "doubled up" thin ones it will sound like a person "blowing" through a paper with lips, squeal like. That carb should be torqued in a pattern, and progressive i.e 7 inch pounds all around, then 14 inch pounds all around. I'd suggest to check for a base gasket leak if it is, running, spot spray at the carb base with starting fluid (I use WD-40), if you have a leak there it will raise the rpms.

clintsy

Ok thanks I'll try that.

clintsy

No luck with WD-40 around the mounting gasket.
I also plugged the air bleed and nothing happened.
I grabbed an a/f ratio gauge and everything is in check so I guess I could leave it the way it is unless I could find another place to check for leaks.