At my wit's end Rochester 2 barrel float/needle sticking

I'm a desperate man and I need advice before I start flinging hammers through my windshield.

I have a 400 inch Chevy in my '52 Ford car. It's from a '73 Chevy truck. Has a '68 Chevelle 2 barrel intake and carb on it, small pattern Rochester "2 jet". Stock mechanical fuel pump I believe. When it gets warmed up, the float or the needle sticks until it pushes gas up through the top of the carb, out that little pipe that leads to the float bowl.

Carb was rebuilt by a friend of mine, have had it apart at least 4 times, tried swapping the new needle and seat back for the old one, tried swapping the whole top lid piece of the carb off because that spring-on-a-stick thing seemed to be sticking (don't know what that's called).

It just refuses to work. It'll work for a little while, but the issue keeps coming back. Am I missing something? I could damn near cry. I don't know what's wrong or what to do differently (I'm a welder/bodyman, not much of a mechanic)

Please help. This is the car (if it makes a difference, everyone likes pictures)

 

Put a Flathead in it

 

Just from what you did try, but did not replace.... I'd look at the float. Is it composition that could get "heavy" like some Q-jets, or is it brass that might have some gas in it?

 

Three things have caused this problem for me..

1) float level set incorrectly.

2) needle/rod/pin/whatever ya wanna call it that holds the float hinge in place is missing.

3) float is leaking and sinking like the titanic. When the titanic sank it caused problems too...

Here's how I fixed my leaking float, works great.

http://www.jalopyjournal.com/forum/showthread.php?t=681947

Of course, YMMV. But I'd be checking the float level and then for leaky float. It's also possible that your Ford is unhappy with a Chevrolet engine and is trying to self-immolate.

 

Apparently the needle and seat that was in the carb originally was all brass, and the one that came with the replacement had a rubber tip, does that sound right? We tried both sets, still has issues.

 

RLD14, a leaky float seems to make some sense, since it seems like it keeps having issues even when the other items were changed. I might try swapping out the float, I've got another carb for parts, maybe I'll do the hot water check on it first.

How is a float adjusted? I'm pretty new to this shit.

 

Usually, flip the carb top upside down, and there is a measurement from either the top of float or seam, to the gasket surface. You need to look it up in a manual, for whatever car it's from.

 

Use this link for manuals which will provide you the information needed to set the float level etc...

http://www.carbkitsource.com/manuals/index.html

 

Seems to me that the last holley that I put needle and seat in had the same problem, good for a day or 2 then over pressure.
. It turns out that there was a lot of chinese knock off needle/seats on the market and they were crap.
The only other issue I had was too much fuel pressure with the electric pump and once I set the regulator to 5 lbs all was good.

 

I took the float out of the carb on the car, and the one out of the parts carb. I don't see a hole in either, but I don't know if it'd be visible or not. But the one that was in the car has dents in it. Like it got dinged up during assembly. The other one is clean

I still don't know how to adjust it though. Should I just swap the other one in there and try it?

 

Factory manual or carb kit paperwork should show you how to set the float. Basically hold it to where it will close the needle and seat and measure the top of the float at its highest point to the top of the float bowl. You'd bend the arm that the float attaches to to raise or lower it.

However floats don't usually go THAT far out of adjustment unless someone has really fucked with them. It's not something that just goes out of whack under normal use.

As far as a hole goes, I couldn't physically see the one in my float without a 10x loupe. We're talking microscopic level holes. Get the float out and dried off, then put it in a pan of water that JUST stopped boiling and look for the tiniest stream of bubbles.

That's to see where the hole is. If you have a hole shaking the float next to your ear generally will produce a sloshing sound. Fuel gets into the float, sinking it.

As far as needle and seats go, check Daytona Parts, they have this kickass needle and seat, I have one in the carter ABD in my Lincoln and its awesome.

 

Moe raises a good point,

If you have way too much fuel pressure no float can overcome it. Remember these carbs are designed to work with really no more than 5-6 pounds of fuel pressure, some aftermarket pumps can produce way more than that, at, say, 10+ psi the fuel pressure can overcome the float and flood out the carb.

 

you can shake the float and just feel or listen for gas inside. I had that problem on the Rochester on my 235. napa had a new one in stock.

 

Been a long time, but, these are mechanical things, and mechanics need to look at the mechanical things.
Seat the needle unless it has a rubber end, you could go so far as to lap it in like a valve.
Check the actual part of the float arm that presses on the needle so see if it can bend under pressure. weak metal
Check the rod on which the float turns to make sure that the float does not bind when moving up to the needle.
And, of course, check the fuel pressure relief valve, should it so be equipped.

Much easier than electrical stuff.

But , remember I am 89 years old and may no longer remember things correctly

 

Well, I took the nicer looking float out of my parts carb and swapped it into the carb on the car. I didn't adjust anything since I don't really know how, but I can move the float up and down and see that the needle is opening and closing.

Took it for a ride and it's not pushing gas out the top anymore, so I'm hoping that the dented up float was the issue, but it was a sporadic issue so I'm going to drive it around some more tomorrow morning just to be sure. I'll also try testing the old float to see if it was leaking, although I couldn't hear anything sloshing around inside of it when I took it out.

I'll report back on what I find. I really appreciate all of the help. I'm no mechanic and I get very easily frustrated with things like these.

 

That's probably a good move. Banged up floats often leak or don't float at the proper level.. Remember ya adjust floats in 16ths of an inch, a damaged one might not sit at the correct level.

 

Hope you have it fixed!

If not, one small item that I haven't seen mentioned: there is a small hole in the float arm which looks like the ideal spot to hang the clip on the fuel valve needle - DON'T! The clip SHOULD be installed, but hang it onto the side or end of the float, never through the hole. Using the hole can cause the valve to bind in about the half-open position and thus cause flooding.

Jon.

 

Reduce fuel pressure to about 3-4 lbs.

 

I vote reduce the fuel pressure too. When I was running the orginal drivetrain in my Scout, I had an electric pump near the tank that put out around 5 psi of pressure. My old Holley 1 barrel leaked like a seive - gas everywhere. I went out bought a pressure regulator and dialed it back to something like 2 psi - no more leaks. It ran like a top until I grenaded the transmission input shaft - twice.

It then got a drivetrain upgrade!

 

Started the car up again this morning, still doing it. Going to get a pressure regulator and try that.

 

I've got a Holley fuel pressure regulator, and it's adjustable, but there's no gauge or dial or anything on it, how do I tell how much PSI it's set at? Also, is it OK to run a pressure regulator after a mechanical pump that doesn't have a return line?

 

That actually is a listing for print outs of the pages out of repair manuals that they have for sale.


When you are setting the float level also check for float drop. The float may be dropping down far enough when the car sits for a while that it is allowing the needle to slide out too far and get in a bind.

Take a look at this and scroll down the page to 6B-33 There detailed instructions for setting the float. The actual setting for the float level might be slightly different for a Chevrolet but the instructions on how to do it are what you are interested in.
http://www.pontiacsafari.com/L1EarlyV8Pontiacs/56ShopManual/6B - Engine Fuel Rochester 2.pdf

If it is a black foam float see if it feels heavy when compared to another float. If it is a metal float shake it and see if you hear anything splashing inside it. It looks like it should have a metal float though.

 

Might just try a remand carb their could be some thing wrong with the carb body.

 

Any time there is a carb issue, and I can't emphasize this enough!!!!!!
You need to know and verify that the fuel pressure going to the carb is correct.
Anything done without knowing that first is a waste of time.

 

+100 on fuel pressure. in the last couple of years I have gone thru 4 pumps on my 283. The failure has been that the pressure would creep up over time. One went to 11psi, one to 15 and the one I changed last week was running nice at 8 and suddenly in about a week went up to 25psi and was bouncing the gauge the the full range.

I need to take that one apart to see what went wrong, Still was pumping enough fuel that it let go leaving the gas station and in a mile and a half pumped out three gallons
out the carb vent


Frank

 

Fuck the 2-Jet. I fought with the one on my Dads '60 Buick for a long time. Rebuilt it, set it 's float, had a carb guy mess with it, regulated it, I did it all. I say get a Holley, Edelbrock or q-jet and take the 2 jet out back and give it a load of 4-buck from old Mr. Remmington.

Not that I have any strong opinions on the 2-jet.....

 

You may get a bad one once in a while Re-Animator but I've run a bunch of them over the past 40 years on my own cars and rebuilt who knows how many and never had a problem with them outside of what someone else damaged before I got to them.

 

I've got (4) 2bbl Rochester 2GVs on my coupe and had the same problem with one of them (the same carb each time) If the float's not working properly, the carb will do exactly what you describe. Seeing how you already changed the float with limited results, it may have something to do with the float hinge-pin assembly, not seating properly or could be dirt in the system, causing the float not to seat/shut off properly. Just a thought, but you're getting some good feedback on this one.

You're going to have to put a fuel regulating GAUGE in the system. I've got the same regulator. I mounted the Gauge (Summit/Jegs sells it) off the left side port, have the feed from the mechanical fuel pump going to the bottom port, and the feed line to the carb/s off the 3rd or last outlet. My pressure is 5-7lbs, but with a gauge, you should be able to adjust easily. If a lower fuel pressure doesn't help, you can always reset it back to the original pressure. (You will need to bush the gauge thread to fit the regulator) Good Luck!

 

That carb is awful small for a 400. You might do better with an intake and carb from somthing bigger, even if it's a stock 2bbl.

 

I went and got an adjustable fuel pressure regulator from Oreilly's, a Mr Gasket one that actually has a dial to show how much PSI it's set at. I set it at 3 and drove the car for a while, I can't seem to duplicate the problem anymore, so I think that might have been it, although 3 psi seems kinda low, maybe I should bump it up one.

I'm going to keep driving it and I'll report back as to whether it keeps working or not.

I really appreciate all the info and feedback here, this is the kind of stuff I'm pretty helpless with.