Carb Question!

[Tenshi95]

Hello all, I have an aftermarket Holley Carb, 4160 iirc, that I rebuilt. The car starts without problem if I give it a few drops of gas from a bottle, but it seems that if I actually push the petal (or move the linkage) that I am getting to gas to squirt into the carb. Once started I can slowly increase engine speed, but if I 'hit' the gas it will stall. Any ideas? Do you need any more info? All vacuum lines are plugged that should be, vacuum advance is going to the right tube. Thanks all for the help! -Robert

[KULTULZ]

I have an aftermarket Holley Carb, 4160 iirc, that I rebuilt.

The car starts without problem if I give it a few drops of gas from a bottle, but it seems that if I actually push the petal (or move the linkage) that I am getting to gas to squirt into the carb.

That is the design. It is the accelerator pump being activated.

Once started I can slowly increase engine speed, but if I 'hit' the gas it will stall. Any ideas? Do you need any more info? All vacuum lines are plugged that should be, vacuum advance is going to the right tube.

Did it do this with the previous carb? If no, you have a problem with the rebuild. Was a quality kit used and were all adjustment procedures followed?

Tip-in hesitation is usually caused (your era engine) by a massive vacuum leak (check manifold vacuum with vacuum gauge), an inoperative or maladjusted accelerator pump or a defective vacuum advance (vacuum motor - breaker plates) (vacuum advance must receive signal from ported vacuum source unless the distributor has been reworked).

Also consider an improperly adjusted choke and/or front float. If the secondary's cut in too soon, the engine will also bog.

[Tenshi95]

Ooops!

"but it seems that if I actually push the petal (or move the linkage) that I am getting to gas to squirt into the carb."

That "to" should be "no"

I don't get any squirt of gas if I move the linkage, sorry bought that.

I'll pull the carb back off and check the accelerator pump. And The carb I had before this was dead so I have no baseline to compare it to, and I used a holley brand kit and followed all adjustments exactly.

Thanks!
-Robert

[DKheld]

When I rebuilt my Ford 4100 on my '60 the results were similar although my accelerator pump was working. It was my first complete 4100 carb rebuild and against my better judgment I adjusted the floats like the instructions said. (this is the original carb and motor - no one has touched it so didn't see how or why the floats would be out of adjustment)

Car was running really rich and rough before the rebuild. After the rebuild it would stall and or backfire through the carb when pressing the accelerator pedal - it idled great.

It basically had a flat spot where it would hesitate but then get past it and rev up. I set the floats back where I remembered they were before following the adjusting procedure in the kit.

Now it runs like a top.

Hope you find something simple like that.

Eric
registry 5347

[KULTULZ]

Ooops!

"but it seems that if I actually push the petal (or move the linkage) that I am getting to gas to squirt into the carb."

That "to" should be "no"

I don't get any squirt of gas if I move the linkage, sorry bought that.

I'll pull the carb back off and check the accelerator pump.

And The carb I had before this was dead so I have no baseline to compare it to, and I used a holley brand kit and followed all adjustments exactly.

Thanks!

-Robert

The engine does run so we know it (carb) is getting fuel. Of course we are not sure of fuel pressure or volume delivery.

If the front bowl is filled (to spec), then the accelerator pump should be filled. There is a spring that rides above the pump diaphragm. Is that there? There is an air gap adjustment @ the pump lever that has to be made that will ensure the diaphragm is not over compressed leading to a ruptured diaphram and then no fuel can be expelled.

If the accelerator pump is adjusted correctly, you should be able to hear it expel air (into front venturies ) when the linkage is opened and this before installation.

The fuel bowl level can be adjusted with the engine running (see instructions) after a preliminary dry setting is performed. These adjustments have to be exact and within the specs for the individual carb model. You can fine tune it afterwards.

[scumdog]

Ooops!

"but it seems that if I actually push the petal (or move the linkage) that I am getting to gas to squirt into the carb."

That "to" should be "no"

I don't get any squirt of gas if I move the linkage, sorry bought that.

I'll pull the carb back off and check the accelerator pump. And The carb I had before this was dead so I have no baseline to compare it to, and I used a holley brand kit and followed all adjustments exactly.

Thanks!
-Robert

Sounds like your problem!

If you push on the pedal/move the linkage and look down the carb (WITHOUT the motor running preferably!) you should see a fair amount of gas squirting down the front two bores of the carb each time the linkage is moved.

The symptom you described points to your accelerator pump not working, check that part of the carb first, especailly that little 'toggle' that goes under the front float-bowl on the drivers side.