Weird Holley Accel Pump problem UPDATE

Posted By: topside

Weird Holley Accel Pump problem UPDATE - 02/09/13 11:56 PM

Here's something I've never run into before (800DP):
When running, Sec pump arm is locked, won't move. Pull carb off, disassemble, reassemble, works fine. Back on motor, start up, locks up again. Check ball @ pump is free, arm isn't bent. Right now with engine off, adjustment backed completely off, still locked.
Probably the 20th Holley I've been through at least; what did I miss? Carb was built up from a buddy's spare parts but otherwise seems OK.

Posted By: 70AARcuda

Re: Weird Holley Accel Pump problem - ??? - 02/10/13 01:14 AM

did you replace the pump diaphragm ?

had something happen on primary pump..

Posted By: topside

Re: Weird Holley Accel Pump problem - ??? - 02/10/13 01:18 AM

Oh yeah, all new gaskets & etc.
I should add that when I check it before putting it back on the car (no gas in carb), the lever is free.

Posted By: Quicktree

Re: Weird Holley Accel Pump problem - ??? - 02/10/13 01:30 AM

it could be clogged somewhere not letting fuel out.

Posted By: Pacnorthcuda

Re: Weird Holley Accel Pump problem - ??? - 02/10/13 01:38 AM

Could the intake be interfering with the pump arm? I had that happen with a 50cc pump on a eddy RPM

Posted By: 5spdcuda

Re: Weird Holley Accel Pump problem - ??? - 02/10/13 01:41 AM

Check the float bowl gasket. There is a small hole in the gasket for the fuel to flow through. Sometimes if you reuse a gasket often enough the hole becomes flattened and distorted enough to prevent fuel flow.

Posted By: Sixpak

Re: Weird Holley Accel Pump problem - ??? - 02/10/13 01:43 AM

I've had the hole in the bowl gasket close up when the screws holding the bowl get tightened. Check the die cut hole in the gasket. Teflon coated ones tend to do it less, the black thick paper ones or brown ones are usually the culprit. Old bowl gaskets used to only punch one hole for the pump passage and if you put the gasket on backwards it would block the hole. Most new gaskets have two holes in them to prevent this problem.

Posted By: topside

Re: Weird Holley Accel Pump problem - ??? - 02/10/13 03:02 AM

I'll get the carb off & check the bowl gasket, passages, sec. needle & seat. Arm isn't hitting anything. I'm amazed at how locked-up-solid it is.
Thanks for the input so far.

Posted By: barracudabob

Re: Weird Holley Accel Pump problem - ??? - 02/10/13 04:20 AM

Quote:

I've had the hole in the bowl gasket close up when the screws holding the bowl get tightened. Check the die cut hole in the gasket. Teflon coated ones tend to do it less, the black thick paper ones or brown ones are usually the culprit. Old bowl gaskets used to only punch one hole for the pump passage and if you put the gasket on backwards it would block the hole. Most new gaskets have two holes in them to prevent this problem.

X2 Had this happen on a 600 Holley. Gasket only had one hole for acc pump. I had it on backwards, and the arm wouldn't move.

Posted By: hustlin hoosier

Re: Weird Holley Accel Pump problem - ??? - 02/10/13 04:35 AM

You have a plugged passage somewhere . since it impossible to compress a liquid the arm is loched solid.

Posted By: sam64

Re: Weird Holley Accel Pump problem - ??? - 02/10/13 03:10 PM

i would be looking at the check under the squirter.

Posted By: topside

Re: Weird Holley Accel Pump problem - ??? - 02/10/13 07:00 PM

That looked OK last time, but I'll have the carb off & apart later today and check passages, gaskets, etc. I'll post what I find...or another question...
Appreciate the input so far, thanks.

Posted By: CHAPPER

Re: Weird Holley Accel Pump problem - ??? - 02/10/13 07:09 PM

Quote:

i would be looking at the check under the squirter.

Have seen them get a burr where they seat. I take a small pin punch and place on the top of the check, while it is seated, and tap with a hammer to clean up the seat/check area.

Posted By: topside

Weird Holley Accel Pump problem UPDATE - 02/10/13 09:02 PM

Turns out the metering block (where the jets & PV attach) has NO HOLE at the gasket surface to feed the accel pump. Gasket is fine & correctly located. Accel pump squirts when the bowl is removed.
Seems like if I drill that hole into the passage (obviously blow air through to clean & test) that it'll work.
Accel pump must be filling with fuel and without a route out to the block, the lever can't move, right?
What size hole: same as the depressed locating area?
Anyone seen this before?

Posted By: bigtimeauto

Re: Weird Holley Accel Pump problem UPDATE - 02/10/13 10:22 PM

you have a vac secondary meetering block not one from a dbbl pumper

Posted By: topside

Re: Weird Holley Accel Pump problem UPDATE - 02/10/13 10:45 PM

D'oh!

Any idea on hole size? Passage is drilled near PV, well plug at bottom of diagonal feed passage tells me that's drilled. My guess is that same size as hole near PV is OK, but...

Posted By: bigtimeauto

Re: Weird Holley Accel Pump problem UPDATE - 02/10/13 10:55 PM

its actually 3 holes you will have to drill and then plug the bottom of the block where you drill. just look at your front block.

I'm not even sure if you have the boss in that block. not to mention the fueling is also going to be off as the emulsion tubes are different on pumpers versus vac secondary carbs.

Posted By: topside

Re: Weird Holley Accel Pump problem UPDATE - 02/11/13 02:12 AM

Actually, 2 of the passages are drilled, just not the one to the diagonal feed from the pump. But your comment on the emulsion is a good thought: probably not a good idea to screw up the "baseline". Found the proper block for sale, which is most likely the best fix.
Moral of the story here is to NOT throw a carb together during a few beers with friends in a nearly dark garage!

Posted By: CHAPPER

Re: Weird Holley Accel Pump problem UPDATE - 02/11/13 02:49 AM

This should be in the DAMHIK thread...

Posted By: topside

Re: Weird Holley Accel Pump problem UPDATE - 02/11/13 03:59 AM

That crossed my mind, but it's embarrassing enough already!