New to Carb motors... could use some guidance.

[el corvino]

My 1987 Cutty Supreme with the 307 was completely gone through 2 years ago (sold to me in November of this year) and I left it up north when I went to Florida for about 3 to 4 months. Jumped the battery and not a single issue since... until now.

When punching to WOT, it stutters and chokes out a bit. If I immediately release the gas and the punch it again, No issue what so ever and right back on track. Any ideas on where I should start looking?

 

[MrSony]

Is it the factory carb? In this cold weather, carb could be gummed up. Or it could be a worn accelerator pump. But that's unlikely since you said the engine was gone through, which hopefully means the carb was too. Not to many people know how to actually fix and diagnose a qjet, let alone a CC one. http://www.hemmings.com/magazine/mus/2007/05/The-Inner-Workings-of-the-Quadrajet/1451978.html Also this is quite the read, give you a better understanding of the qjet's innards.

 

[PartsPile]

The Q-jet in my Grand Prix needed extensive cleaning after sitting for a few years, and even then, it would sputter under hard throttle for a few weeks afterward just like you describe before it digested all the gunk and cleared up. (I had feet on BOTH pedals at stoplights for a bit there to avoid embarrassing stalls, if it survived the initial stumble, it'd stay running fine) Sounds like the accelerator pump may have some fouling.

 

[el corvino]

I have the dealer receipt... so I would hope so. haah It also did go from 65 degrees to currently snowing, so if that's a possibility...

 

[el corvino]

oh no, from a dead stop it takes off and drives like normal - no issues at all. It's if I punch it to pass someone, I just noticed it does this

 

[MrSony]

Hmm.. sounds like it might be getting too much gas then at WOT while already at speed. If it's the factory qjet, take a few hours and take the carb off, grab an old tooth brush qtips and carb cleaner and get to work. Even if that doesn't solve the problem, it's one less thing it could be. Also check the linkage to teh carb and on the carb itself. Check for any vacuum leaks (ssssssssssss noises that get louder when engine is revved) and check the spark plugs and end gap.

 

[PartsPile]

Well, this is a prime example of why anyone who longs for the "Good ol days" before fuel injection should be beaten, severely.

In addition to the accelerator pump, I had two bad plug wires inducing misfires, things like this could be a combination of tiny things adding up.

 

[MrSony]

Well, this is a prime example of why anyone who longs for the "Good ol days" before fuel injection should be beaten, severely.

My 4 barrels whole heartedly disagree When in PROPER working order, Quadrajets are the most fuel efficient carburetor. Period. Some say it even runs as good as a modern (as in early 2000s) fuel injected car.

 

[PartsPile]

I'm getting spectacular mileage for a 38 year old V8 that has 1 hour driving a day... can't disagree.

 

[MrSony]

Well, this is a prime example of why anyone who longs for the "Good ol days" before fuel injection should be beaten, severely.

In addition to the accelerator pump, I had two bad plug wires inducing misfires, things like this could be a combination of tiny things adding up.

And for the record, fuel injection in it's basic form has been around since the 20s. Only as of the past 20-30 years have we started to get good at it.