when I get into about third gear it will start to miss and the faster I go the more it misses. If I slow it down a bit it will go back to normal. My carburetor is very old and already has problems accelerating, could this be the problem? HEI with mopar distributor and ACCEL 8140 Coil. New plugs set to 45 gap. 10 degrees BTDC.

When I put in the new fuel pump there was a old O ring in the fuel valve at the carburetor, it was in pretty bad shape and was leaking fuel all over the place. I took it out and it stopped leaking, but I bet that O ring worked like a shim on the valve and kept it farther out, am I right? Maybe Im not getting enough fuel in the carb

Did you make these changes after you switched to HEI, or before?

Also, HEI modules tend to misbehave if you have the distributor pick-up coil wired in backwards.

_________________
"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

At first I thought it was related to HEI since it sounds like spark failure, but It may also be not enough fuel in the carb. I suspect not enough fuel since it started doing this right after I replaced the fuel filter, and the broken seal on the carb fuel valve. It was running with HEI perfectly before this.

I was right with the cause of the problem, so how high should the float go when it cuts off fuel flow?

What type of carb.? That may help.

Also, I think that part number for your Accel coil is for a points type ignition. I'm not a huge fan of Accel coils, I like and run an MSD Blaster II two with their .8ohm resister (that you of course don't need). If you still have a misfire after adjusting your float level, switch coils with a coil made for electronic ignition and see what happens.

1920, the accel is universal

Oh, well for a 1920 the top of the float (flat part) should be parallel with the top opening of the float bowl. Its easier with the carburetor upside down, but you can do it on the engine as long as you use very light upward pressure on the float so you don't push the needle valve into its seat. Do you have any type of gasket for the fuel inlet/needle valve assembly?

that gasket started leaking, so when I removed it the needle valve moved in, so should I compensate by adjusting the float or find another gasket?

I would find another gasket. However, removing it should not make that much difference unless it was set way low already. You say your carb is old, so just get a rebuild kit and throw at it. They are easy carburetors to do, and you'll get a new inlet gasket. If you need help with the rebuild, don't worry. Plenty of people here to help you out if needed!

I set the float parallel and will probably get the rebuild kit sometime soon, thanks for the advice.

If I were to buy a new carb what would be best for mileage?

Get a 1920 Economaster from SlantSixDan. Hopefully he still has some for sale. It is a great carb! I can burn rubber with a posi and still get good mileage. The #57 jet is my all round favorite for spunk and economy.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

what kind of mileage you get with it?

Look below at the build below my name.

From 22 to 24 mpg, that is (stop and go) city and freeway combined. I haven't taken it on a trip yet to find out what it will get.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG