Quadrajet fueling problems!
Thread Starter
4th Gear
Joined: Jul 2011
Posts: 4
Likes: 0
From: Bloomington IL
Quadrajet fueling problems!
Ok so I have an 81 vette with a 355ci, edelbrock intake and for the last 2 years I have been using the original quadrajet carb and distributor. In 81 it was the first non California vettes to have the computer controls and I had eliminated them when swapping in the new 355 engine. Well this spring it started loading up and dieing out on me when idling and then Id kill the battery trying to get it restarted again because it would flood. Ive since swapped out the carb and distributor out of a 78 vette and I got it to run ok for a while but its back to the same issues. I can barely get it to start and then when I do I can only get it to idle at 1200rpm at 4 degrees advanced in park/neutral. When I put it in gear it bogs down and dies. It has the 350 trans with stock torque converter but it ran fine for 2 years like this so I would like to think its not the problem. Any ideas???
Melting Slicks
Joined: Jul 2006
Posts: 2,291
Likes: 492
From: Salmon Arm, BC
have you adjusted the idle mixture screws?.....screw in to lean mixture, and out to richen mixture. Hook up a vacuum gauge if you have one and try to get the best (most) vacuum reading with a nice stable idle.
Thread Starter
4th Gear
Joined: Jul 2011
Posts: 4
Likes: 0
From: Bloomington IL
Yeah I've been messin with the idle screws all over the place and every which way seeing if anything would work, I had seen looking online that at the highest vacuum point is where you want them and its right around 15in vacuum no matter where they are set. The only difference in running is when I completely lean out the mixture screws in but other than that there is little noticeable difference.
Burning Brakes
Joined: May 2008
Posts: 1,116
Likes: 5
From: Middleburg Florida
Might be a combination of issues. Are you sure there aren't any vacuum leaks? Maybe look for those first, and then, are you sure it's a rich condition and not running out of gas? Maybe a fuel pressure guage to help verify it's not rich condition??
Racer
Joined: Nov 2004
Posts: 485
Likes: 1
From: Oakville ON
Stock type cam? The reason I ask is my L82 cam gives 17 - 18" vacuum at idle in neutral (stable 750 rpm). So I think you have a vacuum leak - probably on one of the vac hoses.
If you are sure it is a rich start condition, on a QJ put your foot to the floor once and hold it there (do not pump the gas!). The unloader mechanism, if set right, will clear the rich condition and she will start.
If you are sure it is a rich start condition, on a QJ put your foot to the floor once and hold it there (do not pump the gas!). The unloader mechanism, if set right, will clear the rich condition and she will start.
Thread Starter
4th Gear
Joined: Jul 2011
Posts: 4
Likes: 0
From: Bloomington IL
Stock type cam? The reason I ask is my L82 cam gives 17 - 18" vacuum at idle in neutral (stable 750 rpm). So I think you have a vacuum leak - probably on one of the vac hoses.
If you are sure it is a rich start condition, on a QJ put your foot to the floor once and hold it there (do not pump the gas!). The unloader mechanism, if set right, will clear the rich condition and she will start.
If you are sure it is a rich start condition, on a QJ put your foot to the floor once and hold it there (do not pump the gas!). The unloader mechanism, if set right, will clear the rich condition and she will start.
gross lift .477 intake and .480 exhaust
duration .509 intake and .512 exhaust
duration @ .050 224 intake and 231 exhaust
lobe lift .3180 intake and .3200 exhaust
lobe separation 110.0
running 1.6 rockers
