ROCHESTER 4 BBL. CARB

[lenray]

I have 5 tractors-----Have this jaguar car with the V-12 REMOVED and replaced with a GM 350 4 bolt main engine with a 4 bbl. Rochester carb.
Just got the car--big mistake not my first--.
Broke down 6 times coming back to Michigan from the south.
Starts good runs very fast, BUT when you come of the freeway to get gas and slow down it stalls. Try to restart gas everywhere flooded. Will start after sitting for an hour.
Took the top off of the carb along the road and it was very dirty down in the bowl. Cleaned out and it ran good again.
It just stalls out on low RPM and will not start---flooded.
Need help and advice. THANKS

 

[Anonymous-0]

The float in these carbs are known to absorb gas and get heavy. There is a float that is better but I have forgotten the #.Most likely all you need is pull the top off and(replace and set)the float and a new top gasket. Do the needle & seat too.

 

[Anonymous-0]

That's one reason those who don't know their idiosyncracies call 'em "Quadra-JUNK" carbs.

For a brass float, try this link:
Quadrajet Floats

 

[Lamar Fudd]

I walked into the parts store with my q-jet float in my pocket. Parts man checked to be sure he had a replacement, then dug his thumbnail into it; gasoline oozed out. That new float cured it. Quadrajets are good carburetors-this from a Ford man that replaced his Autolite carburetor with a Holley.

 

[bradk]

Needs an overhaul plain and simple.If you haven"t done a Q-Jet before,take it to an older repair shop with experience with them.Needs a good soak with REAL carb dip and overhauled with a quality kit and nitrophyl float.Not sayin" you can"t do it,but some things are better left to the experts.

 

[Brian Jasper co. Ia]

You want a brass float. If you do the rebuild, dip type cleaner is what you want to use. Don't forget to file the top flat. Most Q-Jet carbs that don't work right are caused by someone overtightening the 2 front bolts putting it on the intake. The two front bolts go through the top and body and when overtightened, they warp the top and then it never idles right.

 

[Bob]

All the other guys are dwelling on the float and forgetting about the possibility of leakage from the lead "BB" and aluminum plugs in the fuel passages under the main body of the carb. These and loosen and leak or fall out altogether dumpimg LOTS of fuel.

Here's some photos of the plugs showing how one outfit puts screw-in plugs in. Most guys just clean 'em up and slather epoxy over them.

<img src = "http://www.mre-nnalert/quadrajet/images/plugs.gif">

<img src = "http://www.mre-nnalert/quadrajet/images/screwinplug.gif">
PLUG those holes

 

[buickanddeere]

Holley makes a retro-fit stand alone O2 sensor feedback fuel injection system.

 

[Anonymous-0]

Edelbrock does too...so what's your point?
Edelbrock EFI

 

[buickanddeere]

Why fool around with a carb when the fuel injection runs better and uses less fuel? Use a TH700R4 trans with lockup for even better fuel efficiency.

 

[Anonymous-0]

Let's see...the guy starts out by saying he's "cheap," so you recommend he change to a $2-3 GRAND fuel injection system, and then ADD a suggestion that he spend even more money for a transmission change.

Do I understand what you're saying so far?

If so, while I agree that swapping to fuel injection can result in better running and better fuel economy...and that swapping his transmission to one with overdrive will also help him achieve better fuel economy...I don't see where he asked about the fuel economy aspect. I beleive he simply asked how to make the car run better, for a low dollar outlay.

And a $400 carburetor [see my link to the Edelbrock remanufactured Q-jet below] seems to be a much less expensive solution to the problem...although repairing his current Q-jet and replacing the phenolic float with a brass one [see my link below to a source for brass floats for Q-jets] would be less expensive yet...even if h has to pay someone else to do the work.

Or maybe $3000 IS cheap, in your eyes...but $3000 is a lot of money, in my eyes. Maybe that's the difference, our frames of reference.

 

[Fred Martin]

OT OT Me and our church fishing group were up at Port Clinton, Ohio a couple of years ago at a Stop and Rob getting morning coffee and on the way out an older Jag started up and you could tell it had a cammed up V-8 in it. We watched it take off and I told the guys up ahead of me that I'd just as soon have a good chevy. One of them turned around and said "Did they make one!" This year who drives up to the church in a new chevy??? And did I rub it in when the fishin crowd was in ear shot. smile. ohfred

 

[Hobo,NC]

I don't think I would admit I could not fix one :wink: That's a good link thanks for the tip... My tip try windex any were you would normally use soapy water,,, it works great look'n for leaks... especially on AC leaks... What the magic is about it is dunno but it works were nuttin else will...

 

[36 Coupe]

I bought my Chevy pick up from a fellow who complained about poor gas milage.I found a plastic float that had absorbed gas and a vacuum advance that didnt work.The truck was easy on gas if you didnt lead foot it.Truck was a 3/4 ton and did plenty of work.Salt ate the frame up.No pollution garbage on it.It had a radio,heater,power steering and brakes.Good basic truck.