Frustrated with Carb

[wagerton]

I'm thinking about killing my car,...painfully and with great malice.
I cannot get the weber carb to run correctly,...I have a 1.9, with a header and the Weber. I thought I had vacuum leaks so I replaced the paper gasket with the thicker one from OGTS,...also replaced the electric solenoid with a regular weber idle jet holder. Electric chokes seems to schedule correctly (plates open over 3-5 minutes)I also blocked off all (incl brake booster)the vacuum lines under the carb. Trouble is that is runs correctly sometimes and at other times (most of the time)it just stumbles and won't initially take the throttle when accelerating. So I replaced the Accel pump innards. It squirts fuel OK when I look down the throat. No change with the accel pump renewal. Clear see through fuel filter,...looks clean. The float bowl should hold enough fuel so that the accel pump can squirt so low fuel pressure doesn't seem logical.
I was wondering about Carb Icing as a cause since it usually is much worse in the morning when the temp is down. For icing to occur I'd need humidity and we don't have that in the desert. Has anyone had trouble with the Carb just being too cold to atomize fuel? Since the exhaust manifold no longer heats the intake under the carb That came to mind. Timing checks out. I even raised the float level a little and richened the idle circuit,...no change.
I'm obviously not seeing some part of the big picture here,...

[BQS4]

Originally Posted by wagerton I'm thinking about killing my car,...painfully and with great malice. I cannot get the weber carb to run correctly,...I have a 1.9, with a header and the Weber. I thought I had vacuum leaks so I replaced the paper gasket with the thicker one from OGTS,...also replaced the electric solenoid with a regular weber idle jet holder. Electric chokes seems to schedule correctly (plates open over 3-5 minutes)I also blocked off all (incl brake booster)the vacuum lines under the carb. Trouble is that is runs correctly sometimes and at other times (most of the time)it just stumbles and won't initially take the throttle when accelerating. So I replaced the Accel pump innards. It squirts fuel OK when I look down the throat. No change with the accel pump renewal. Clear see through fuel filter,...looks clean. The float bowl should hold enough fuel so that the accel pump can squirt so low fuel pressure doesn't seem logical. I was wondering about Carb Icing as a cause since it usually is much worse in the morning when the temp is down. For icing to occur I'd need humidity and we don't have that in the desert. Has anyone had trouble with the Carb just being too cold to atomize fuel? Since the exhaust manifold no longer heats the intake under the carb That came to mind. Timing checks out. I even raised the float level a little and richened the idle circuit,...no change. I'm obviously not seeing some part of the big picture here,...

Well before you kill the car, was the weber a recent replacemet for the OEM solex? If so, did you use the phenolic spacer that was with the solex? This would have 4 1/2 moon notches in it to allow access to the 4 screws holding the intake and exhaust manifold together. The problem is, when you put a weber on this phenolic spacer, it does not account for these 4 notches and thus you have vacuum coming in at 4 spots. You need to cut a new spacer without these notches and that will cure the problem.

[wagerton]

well no the weber has been on there for 10+ years,...and worked fine,...I pulled it off to do the header and when I replaced it it had a audible vacuum leak,...OGTS sold me a solid spacer that keeps those crescent areas blocked off. If there is a vacuum leak right now I cannot hear of feel it,...I even used the tube stuck in the ear method to listen around the carb and manifold to head junction.
This is very frustrating,...

[wrench459]

Originally Posted by wagerton Trouble is that is runs correctly sometimes and at other times (most of the time)it just stumbles and won't initially take the throttle when accelerating.

Have you checked the fuel volume from the pump?
On a F/I unit it should be around a pint in 15 seconds.
But I forget what it should be for a carb. Dang oldtimers!

[Paul]

Originally Posted by wagerton well no the weber has been on there for 10+ years,...and worked fine,...I pulled it off to do the header and when I replaced it it had a audible vacuum leak,...OGTS sold me a solid spacer that keeps those crescent areas blocked off. If there is a vacuum leak right now I cannot hear of feel it,...I even used the tube stuck in the ear method to listen around the carb and manifold to head junction. This is very frustrating,...

I had the same problem.... One day Weber ran great and the next there was a vacuum leak... But not one that could be heard...

Fought with the problem for 4 months... Replaced new gaskets several times, tried a loaned Weber from a know good running car (thanks Gene)... even bought a NEW carb... Finally replaced the phenolic spacer with one I made at work, to get rid of the notches.... Waa Laa the problem was fixxed...

I don't know what spacer OGTS sold you but I worked with them several times over the phone and they never indicated they had a replacement for the phenolic spacer... that's why I made one at work. Did the spacer you installed have a plastic insert at each stud hole?

[RallyBob]

Originally Posted by wagerton well no the weber has been on there for 10+ years,...and worked fine,...I pulled it off to do the header and when I replaced it it had a audible vacuum leak,

If it was a Pacesetter header, then it's likely that the header flange differs in thickness from the intake manifold flange. So if the header flange is thicker, then the intake will NOT ever seal to the head properly. Something to look at anyway, and not uncommon given the fact that the Pacesetter flanges are 'trued' by hand with a disc grinder rather than milled or blanchard ground.

The correct thickness is 12 mm or .472", BTW.

Bob