I've got a '64 Parisienne Cutom Sport with a 283 2-speed, and I replaced the worn two barrel with a rebuilt Rochester four barrel on a cast iron intake.. The car runs terrible, bad idle, stalling, etc, and I can't seem to tune it in. I've replaced plugs, cap, rotor, and still no change. I've been told by numerous individuals to dump the Rochester and get a Holley or Edelbrock. A few friends have done this and the cars run great without any tuning. Which carb would be the better choice if I went this route.
Have you checked for air leaks around the base. Have you adjusted the air idel mixture screws ? Do you have the correct base gasket ? I think there was something about the intakes with the hot slot on it you had to use the thin stainless insulater sheild .
I saw a white 64 conv. running down Day street the other day was that you ?
No, not me. Mine is red in color. I've set the idle mixture screws but don't have the ss shield. Could be a leak there. Thx for the info, will check on that.
I would keep working with the Rochester to get the bugs outs. Holley or Edelbrock(Carter) are no better or trouble free.
I agree. Who rebuilt the Rochester? Any chance of getting them to have a look at it? A vacuum leak anywhere can kill you so make sure everything is nice and tight. Your problems sound like they could be float related, does the car seem like it could be starved for gas?
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Hillar
1970 LS4 (eventually an LS5) Laurentian 2dr hdtp -and a bunch of other muscle cars...
I'd fix the q-j. Does the intake have an internal balancing tube? Or do you have an exhaust tube? Could be a pluged port on the Intake b-t, causing carb icing/starving?
what is that rochester off of? It looks like a quadrajet from the late 70's - or 80's. Was it rebuilt? The offset air cleaner stud and fuel inlet are my clues that it's for a much later engine.
Carbs are tricky items, and to be honest it looks like you've taken something from a later model car, and you're expecting it to work on something it wasn't designed to work on. There are numerous variables in the carbs, and any one of them can be the culprit.
- we had a guy in our local club that grabbed a quadrajet off a car in the scrap yard, then had someone rebuild it to the specs of a particular carb for his 455 SD. They said "no problem". It never worked right, and he now badmouths quadrajets. I double checked this concept with John Sawruck at a POCI convention. He said this fellow was sold a bill of goods, you have to start off with the right carb as there are numerous variables, and the carb body is built a particular way.
I agree, Qjets are probably the most reliable carb ever. Just need to get a good rebuild on it by a good ol GM tuneup guy & you'll be fine. :If you change your mind though, I have a square bore Edelbrock(carter) with an electric choke almost new. They are probably the simplist carb out there and the 600cfm would be just right on your smalllblock.
-- Edited by Elroy on Friday 3rd of July 2009 10:52:57 PM
Thanks to everyone for your help and input. I will keep the Roch and get it rebullt properly. Seems to have a bad vacuum leak that has gotten real bad since last time. It is a late 60's model but I'm guessing the rebuild was more amateur than I expected. Got it cheap so I can't really complain.
I know I'm months too late with my input but I bought a rebuilt 2 barrel and had the same problems - until an experienced guy found a hole behind the carb (right low down where it was difficult to see) that hadn't been plugged in the rebuild. It runs fine now, but - just like the old one - if I leave it more than a few days I have spray fuel on the air cleaner to start it.
I know I'm months too late with my input but I bought a rebuilt 2 barrel and had the same problems - until an experienced guy found a hole behind the carb (right low down where it was difficult to see) that hadn't been plugged in the rebuild. It runs fine now, but - just like the old one - if I leave it more than a few days I have spray fuel on the air cleaner to start it.
That's a fuel pump problem. It's leaking back instead of maintaining minimum pressure, usually around 3-5 psi
I know I'm months too late with my input but I bought a rebuilt 2 barrel and had the same problems - until an experienced guy found a hole behind the carb (right low down where it was difficult to see) that hadn't been plugged in the rebuild. It runs fine now, but - just like the old one - if I leave it more than a few days I have spray fuel on the air cleaner to start it.
That's a fuel pump problem. It's leaking back instead of maintaining minimum pressure, usually around 3-5 psi
I would second that. I've had the same problem, and a fuel pump should cure it.
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1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars
A genuine GM replacement pump was fitted at the same time as the carb. The problem used to annoy me but I've got used to it now. I just feel lucky to have one of the handful of RHD 64s in the UK.
The other possibility is that the carb bowl drains out when it is parked. However, that should also cause flooding if you shut it off and try to restart it an hour or two later, if the bowl has drained into the intake. Do you have any trouble with a restart after it has been parked for an hour or two?
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1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars
Thanks all for your distant diagnosis. Carl, my first thought was that the float chamber was somehow draining but I (touch wood) never have any trouble starting hot or cold winter or summer - except if I leave her for more than about 3 days or so when I need to "prime" through the air cleaner. I figure perhaps the chamber is draining somehow but so slowly it causes no other problem. Strange thing is it's exactly the same symptom with rebuilt carb and new pump as it was with the 45 year old original parts.
just the float being out a very tiny little bit for me was the problem i had with my two barrel on a 283. I had the same symptoms and even after the rebuild same thing. I took it apart 4 times and then realized the float was off a bit, fixed it and runs great. Same thing when i had a 4 barrel on my rochester, it was just in need of a rebuild and i had a guy calibrate it afterwards and never had a problem. I find the roch. easy to use and im a dumbass!!!LOL
That's interesting. I wondered if that was the problem after fitment back in the summer and adjusted the float on the rebuilt carb to hopefully fill the chamber a little more. My amateur effort didn't make any difference Is there a more exact way to adjust the float or is this something only an expert could do?
In a rebuild kit you get a carboard caliper to use but any measuring tool should do. You measure from the float seam line with gasket in place. Looks like float line should be 3/4 in. from closed position (upside down with float clossing the neadle and seat) and float drop should be 1-3/4 in. (right side up).
