Q-jet suddenly running WAY too rich, choke is open, should I .......

[mtnmankev]

As the title says, the Q-jet is suddenly running WAY too rich for no apparent reason.
The choke is fully open.
I am tired of messing with carburetors, so should I shoot the Q-jet and install the Edelbrock 1405 I have rebuilt and sitting on my shelf ?

 

[Blue Ox]

 

[RecklessWOT]

With as much hate as they get, I feel the quadrajet is actually a decent carb. They can get finicky at times, but if you get it dialed in there's no reason to shoot it. Without being there I can't tell you exactly why it's running the way it is. Are you sure everything is clean, nothing is worn out? Fresh fuel, truck hasn't been sitting? Not a single little chunk of dirt or varnish hanging out in there? How many miles on the rig? Everything look normal? Could be something as stupid as a stuck float and bogging out, have you tried banging on it with a screwdriver handle or the like?

 

[mtnmankev]

It's been doing great up till now, then it suddenly went to crap.
I can build them, but I hate doing it.
I was tired of having to depend on an undependable electric choke screwing me up, and despite my plans to invent a manual choke conversion for the Q-jet since none exist, I now have a manual choke and am in full control of cold engine starts.
The engine sounds beautiful with the 1405 on it, it even sounds happy .......
I will probably give the Q-jet a quick cleanup and throw it in a box with a bunch of other Q-jets and parts, and find a buyer.

 

[Dave M]

Don't be too quick to get rid of the old Quady , I'm a big fan of them and l have read on this forum the Edselbrocks can have their fair share of issues also. I put a rebuilt quady on my 454 and upgraded to the electric choke. Fires up nice, for the cold mornings we are heading into. Rebuild the quady while your vehicle is still running, you might change your mind later on.

 

[Matt69olds]

I bet the power piston is stuck. Engine vacuum is supposed to hold the piston down, as vacuum drops the spring is supposed to raise the metering rods out of the jet. If the piston is stuck in the raised position, the mixture is going to be rich.

Spray a bunch of carb cleaner down the vent tube in the carb. If the engine ran well with the Q-Jet, no reason to swap to the Edelbrock.

It’s hard to beat a well tuned Q-Jet for a street engine.

 

[mtnmankev]

The q-jet has been running fine since I rebuilt it a few years ago.
I might blame its issues on the rough roads I live on, or the space aliens messing with me (tough choice to make).
But, I am at the point in my life where failing health causes me to not do anything mechanical unless it's an emergency, like somebody is dying or the house is on fire.
That said, the q-jet is now sitting on the workbench and I am not going to mess with it.
The truck loves the edelbrock, so that's how it's going to be.
I do thank you for the advice and tips, though .......

 

[Garageman402]

The q-jet has been running fine since I rebuilt it a few years ago.
I might blame its issues on the rough roads I live on, or the space aliens messing with me (tough choice to make).
But, I am at the point in my life where failing health causes me to not do anything mechanical unless it's an emergency, like somebody is dying or the house is on fire.
That said, the q-jet is now sitting on the workbench and I am not going to mess with it.
The truck loves the edelbrock, so that's how it's going to be.
I do thank you for the advice and tips, though .......

Take it out for a spin, and get on it. If it feels a little lacking, go back to the Q-jet. We replaced my Q-jet with an Edelbrock Thermo-quad copy, 650CFM. At times I want my Q-jet back.

 

[mtnmankev]

I will find out tomorrow how it does under load, have to climb a 6% grade at 75 mph for 5 miles.
If I can't maintain at least 70 going up that hill, something is wrong.