Problem with engine loping

[christian]

Ever since I got my slant window up and running I have not been able to get the engine running perfectly. I have been having a problem with the engine loping. By fine tuning the timing and setting plug gaps and point gaps I got it running better but still has a lope, sounds like a snare drum beating for a second, them off for a half second then back on, you get the picture. Distributor is a new unit from snyders, coil new all new wiring, carb is from a reputable rebuilder.

One odd thing I noticed is when I finally gave up fiddling with it, I shut off the gas valve to let it run dry, after a couple moments it started to run perfectly, smoother that my wife's 2012 Toyota. Then after about 15 seconds if sputtered and died. Could this have something to do with the problem. I'm guessing its carb related.

Another off thing is that the engine won't run with the idle adjustment screw more that 3/4 open.

Thanks for any input
Christian

[ford3]

sounds like its running rich, check float level and any other fuel settings

[zzlegend]

I open my GAV about 1/4 turn when starting the notor cold and then have to open it to about 3/4 to 1 full turn open when warm to run down the road. But If i forget and leave it open 3/4 turn when i start it cold it will also lope. As soon as i reach over and close the GAV to about 1/4 turn it is fine. Just a little to much fuel when cold causes it to lope. Try just cracking your GAV 1/4 turn the next time you start it. Just a thought.

[christian]

I run the GAV at 1/4 when warm

[christian]

I'm going to remove the carb and check the float height, should be parallel hen upside down right ?

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Yes for 90 % of the time, but it is always best to test.

The vendors sell a tool that is a clear plastic tube bent in a U shape that attaches to the carb that shows the actual fuel level. Many floats have been used and abused, replaced, bent, soldered, etc. so the parallel to the seam check or measuring doesn't always work.

If you are anal on carburetors then make sure the flat area of the float that kisses the float valve is flat and smooth so it doesn't hang up the hanging valve pin. Also the pin holding the float to the hinge has to be perfectly straight. Roll it on a flat surface to check. A bent pin here can affect the correct float operation.

[700rpm]

Originally Posted by christian

I run the GAV at 1/4 when warm

That is the correct adjustment, + or - a bit.

[steve s]

Originally Posted by zzlegend

I open my GAV about 1/4 turn when starting the notor cold and then have to open it to about 3/4 to 1 full turn open when warm to run down the road. But If i forget and leave it open 3/4 turn when i start it cold it will also lope. As soon as i reach over and close the GAV to about 1/4 turn it is fine. Just a little to much fuel when cold causes it to lope. Try just cracking your GAV 1/4 turn the next time you start it. Just a thought.

Does this make sense to anyone? It's the exact opposite of how it's supposed to work.

Needing the GAV opened up for normal running suggests either a vacuum leak or a plugged jet or too-lean float setting, none of which are consistent with requiring GAV closed down for cold starts. ???

Steve

[zzlegend]

Originally Posted by steve s

Does this make sense to anyone? It's the exact opposite of how it's supposed to work.

Needing the GAV opened up for normal running suggests either a vacuum leak or a plugged jet or too-lean float setting, none of which are consistent with requiring GAV closed down for cold starts. ???

Steve

Ya Stev. I knew someone would question this, but that is how mine runs the best. I open 1/4 turn when cold and let it warm up. But when taking off to drive it wants to stumble and hesitateI reach over and open about 3/4 to a full turn and it just smooths out with plenty of power thru all gears. No vac leaks and carb is clean and float level good. I remember a couple of others on here that stated that they run theirs about 3/4 turn to run also. My other one with a Tilly seems to run better when open a little more than 1/4 turn. I think all A's have there own little quirks. Go fiqure. This is just what works besy for me.