My vette is running outragously rich! Within 3 weeks of new plugs, they are full of carbin and need to be cleaned, the exaust almost smells like straight gas, and it is starting to idle rough(it was smooth when the plugs where just put in). I have also been racing the engine the last couple weeks to break it in after a 6 year hybornation. I know racing the engine will put carbon on the plugs quickly, but I think 3 weeks is a little ridiculous...? What are my options here? A hi'flo air filter? I saw an air filter on a car on the forum that was triangular in shape, and like a dome, and it was all material, no solid areas except the base place. Is this just a metal mesh to keep big objects out? If the airfilter doesn't seem like the cause, then it must be the carb jetting(???) Its a rochester quadrajet. frankly I do not like this carb, if its not one problem its another. how do I rejet a carb, and how many steps down should I go in jet size (given what I have told you).

Thanks in advance;
Daniel
PS. Sunday begins my big rear suspencion rebuild. I have my digital camera ready.

 

Dan-
A new design air filter will not cure your problem. And stay away from those 'flathead' metal mesh airstrainers. They only keep small animals and sticks from getting sucked in! Sounds as if your carb needs rebuilding after a 6 yr rest. Good poss that the gaskets and float are deteriorated. Not to mention the old gas that was left behind and turned solid. Bet ya that the fuel isn't following its intended path within the carb, so it's just 'dumping' fuel instead of 'metering' it. Don't let this experience give you a bad attitude toward Q-jets. They are a decent carb if set-up right. (although not my choice) They are also fairly simple to rebuild. (which is just a disassembly, clean, parts replace and necess readj) If you d-i-y, take the parts someplace that will 'soak' them in a commercial carb cleaner. This removes all old residue and gunk, and provides the perfect 'base' to rebuild it. Don't mess with any 'rejetting' until you've gone thru above first. Step 2 & 3 is to replace plugs (and properly gapped) and replace old air filter element. Bet ya it'll run just fine as is.
Good Luck-

 

The steel plugs at the bottom of the fuel bowl are notorious for cracking and leaking. That should be one of the first things to check. Second, if you made any modifications to your motor that affects your engine vacuum, that could have a sour effect on the carb too. if all you do is short engine runs where the engine never gets up to operating temperature, you'll get carbon buildup on the plugs right away. Hope this helps.

 

Sounds like you need a new carb or at least a rebuild. Stay away form those air
you saw they are made by Edelbrock and will melt into your carb or even catch
on fire if you backfire.

 

What about your coil and module??
I noticed a BIG :D improvement once I bought the Accel coil and hi-po module.
She starts up quick, and the plug stay cleaner than before.
---I'm not saying this is the root of your problem, but it may be an area you might want look into.

 

Daniel

Your 77 carb is not too rich- it is too lean.

This is probably the problem.
The primary power piston is held down by vac. in idle. You can check w/ engine off by inserting something like straw or screwdriver down bowl vent & lightly press down on power piston assembly, should move down a little & the spring pushes back up. Note how far you are in w/ it up. Now start engine, should be down. Yours is probably up all the time. This would make too rich.
Spray out w/ carb cleaner. Possible vac. leak.

:cheers: