Weber Accelerator pump weak or no flow

[jabb]

Originally posted by mistake in Engine Rebuild Forum

I have a 3.0 with 40 IDA's that has sat for a couple of years.
I have drained all the fuel put in fresh fuel. The car does run but is hard to start.

I recently cleaned idle jets main jets and emulsion tubes.

What I noticed is the accelerator injectors 2 out of the 6 have a good flow.
2 have no flow and 2 of them just dribble.
This is when I am pumping the accelerator pump manually.
I am not sure how to clean / clear this issue.

[Jack Stands]

If it was sitting for a few years, I'd assume that the fuel has turned to jelly and the carbs should be completely disassembled, cleaned, and rebuilt. Paul Abbot @ Performance Oriented seems to be the Weber carb guru, but I understand that he's quite backed up with work. He does have some great information on his website that should be very helpful if you want to try to do the work yourself.

[jabb]

Looks like I can take off the accelerator pump and appears to be 3 passages I can spray with carb cleaner think I will try this before doing a full rebuild. The other jets I cleaned were not that bad and the fuel I drained of was yellow in color it was not that bad.

[moneymanager]

The membranes inside may be shot as well. Think Pegasus has them, not sure about our host but check. The float bowl control valves at the bottom of the float bowls could also be filled with crud. You will need to pull the carbs to get to these.

[yelcab1]

Jabb

Don't do this half ash with the ... not that bad comment. You will have more running trouble down the road. Just get 2 rebuild kits, disassemble, soak, clean, and reassemble. Check for air leaks on the main shaft.

[chris_seven]

The float bowl valves in a 40IDA are already blanked unlike in a 40DCE so they allow maximum flow.

[jabb]

Originally Posted by yelcab1

Jabb

Don't do this half ash with the ... not that bad comment. You will have more running trouble down the road. Just get 2 rebuild kits, disassemble, soak, clean, and reassemble. Check for air leaks on the main shaft.

Your right the more I think about this the more I am leaning towards just getting the rebuild kits and going through the rebuild process also pull and clean the fuel tank.

[KTL]

Like Jack Stands said, do yourself a favor and check out Performance Oriented (Paul Abbott is member 1QuickS here on the forum) for an incredible resource of Weber technical information.

[jabb]

Originally Posted by KTL

Like Jack Stands said, do yourself a favor and check out Performance Oriented (Paul Abbott is member 1QuickS here on the forum) for an incredible resource of Weber technical information.

Thank You I am in touch with Paul......

[1QuickS]

When I service Webers I take special care to perform two tasks which result in even squirt from all squirters:

• rebuild the inlet check valve at the bottom of the float bowl by re-sizing the seat & installing a new check ball
• ream the squirter nozzle passageways with both 0.50mm diameter drill for the tip & a #53 drill for the larger passage

The valve in the screw that secures the squirter nozzle needs to be clean as well.

[matthewb0051]

Once you do rebuild, try using non-ethanol (marine) gas frequently. Ethanol tends to pull moisture in which gums up your carbs. If your area is humid then it compounds the problem. When I lived in Hawaii I ran every other tank with marine gas.

[KTL]

Use marine Sta-Bil