Quadrajet by Jett Performance Stage 2
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 2,297
Likes: 156
From: Clayton New Jersey
Quadrajet by Jett Performance Stage 2
Hopefully somebody can help with this. I have a Quadrajet by Jett Performance 800 CFM Stage 2. My Vette is a 1977 L48/4 speed. The block has been bored 30 over and flat top pistons were installed. The cam is a blue racer, lift is in the area of 480-490. The heads are Edelbrocks Version of the Vortec heads, ported and polished with 2.02's intake and 1.64 exhaust. Intake is also an Edelbrock that has been ported to the heads. I used 1.6 full roller rockers on top so, I'm not real sure were the valve lift would be now.
Anyway, Vette runs great. Until, once warmed up and choke is off it does not want to idle. It's seems to be loading up. If you take off and run through the gears there are no problems. Runs like a bat out of hell. Vette does blow some black smoke when you first jump on it. It smells like its running very rich. I've adjusted this carb every way possible. Maybe its to much carb? It's about to land in the bottom of the trash can.
Thanks, Bill
Anyway, Vette runs great. Until, once warmed up and choke is off it does not want to idle. It's seems to be loading up. If you take off and run through the gears there are no problems. Runs like a bat out of hell. Vette does blow some black smoke when you first jump on it. It smells like its running very rich. I've adjusted this carb every way possible. Maybe its to much carb? It's about to land in the bottom of the trash can.
Thanks, Bill
Melting Slicks
Joined: Mar 2006
Posts: 3,456
Likes: 102
From: Piedmont Va
St. Jude Donor '11-'12-'13,'19-'20
No way it's too much carb for your engine based on the description. Too much fuel at idle:
Float Stuck or out of adjustment
Needle/Seat debris etc
Rich Idle Mixture
Timing off
combination of any of the above.
I'm frustrated with my QJet as well and ordering a Holley tomorrow.
Float Stuck or out of adjustment
Needle/Seat debris etc
Rich Idle Mixture
Timing off
combination of any of the above.
I'm frustrated with my QJet as well and ordering a Holley tomorrow.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Carb was poorly set-up at the factory. Take it back under warranty [if you can], do your own rebuild and make correct adjustments per instructions and Lars rebuild papers, or send to Lars to have him fix it [if he's up-and-running again].
"How you doing, Lars?"
"How you doing, Lars?"
Race Director
Joined: Apr 2007
Posts: 14,062
Likes: 602
From: Henderson Nv-Rohnert Park/Sonoma C o. ca/born in NY Rockaway Beach.
I was just having the same problem with my quad rebuild...
Black smoke and bad idle.
we had to adjust the metering rods and its all good now.. its the best the car has run after my rebuild now.
Black smoke and bad idle.
we had to adjust the metering rods and its all good now.. its the best the car has run after my rebuild now.
Instructor
Joined: Feb 2008
Posts: 140
Likes: 0
From: Tulsa OK
