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Posted by: arkitect Sep 29 2014, 05:31 AM

I've been working on my dual carb setup for awhile now. Thought I would have them sorted by now. Having trouble with getting fuel to the passenger side carb. I can see the fuel going into the driver side fine but the passenger side just barely one barrel getting fuel.

I am using the Weber IDF40 carbs with a faucet electric pump. Maybe not enough fuel pressure?

After the fuel filter I have a single to dual fitting to split the fuel line to the carbs. Stronger pressure to one side?

Any comments would be helpful. Thanks.

Dave

Posted by: stugray Sep 29 2014, 07:18 AM

Explain more please.
How can you tell "barely one barrel getting fuel"?

Posted by: wndsrfr Sep 29 2014, 07:24 AM

Crack the inlet fitting to the passenger side carb......I'm betting that you have adequate fuel there and the problem is inside that carb....

Posted by: jsaum Sep 30 2014, 10:34 AM

Are you using a fuel pressure regulator? Here's a picture of my set up with EMPI 34's on a 1.8. I used a T fitting and didn't have any issues.


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Posted by: URY914 Sep 30 2014, 05:35 PM

Get a real fuel pump and use a real pressure regulator.

Posted by: URY914 Sep 30 2014, 05:38 PM

And an inline pressure gage

Posted by: arkitect Sep 30 2014, 08:22 PM

Here is a shot of both carbs. The driver side carb shoots a nice stream of fuel to both barrels. The passenger side carb, not so much - the barrel closest to the fire wall, dribbles out and the rear barrel has no fuel coming out of the jet.



Here is a close up of the driver's side, the jet is visible in the left barrel, bottom.

Posted by: jsaum Sep 30 2014, 08:55 PM

Try switching the carbs. If the problem follows then you'll know it's the carb.

Posted by: vw505 Sep 30 2014, 09:00 PM

Could be a bad diaphragm

Posted by: jsaum Sep 30 2014, 09:01 PM

Even easier just switch the hoses around. If you have flow problems then it's in the hoses or your connections. Eliminate each section until you find the issue.

Posted by: arkitect Sep 30 2014, 09:20 PM

Thanks for the suggestions. I was thinking along the same line, blocking the fuel line to the driver side carb and see if there is a change.

Switching the carbs, not so easy. I've had the passenger off and on so many times that I'm getting quicker with it. The driver side carb didn't go on as easy and will be a major pain to take off.

It would be nice to actually drive this car instead of it being a yard ornament.

Dave

Posted by: stugray Sep 30 2014, 10:15 PM

So you are talking about when you turn the throttle and the fuel squirts down the barrel?
If so, that is your accelerator pump. And as mentioned above, bad diaphram or clogged jet. Or if you have the adjustable accel pump lever, it may be out of adjustment or broken.

Or do you mean you are looking down the barrel with the engine running and are seeing gas dribble?

Posted by: arkitect Sep 30 2014, 10:48 PM

Without running the engine. I key on the electric fuel pump to get some pressure then throttle by hand to see if I get the squirt. I've checked the diaphram and it's good. Maybe clogged jet?

Dave

Posted by: stugray Sep 30 2014, 11:10 PM

Another possibility is a stuck float.
you can pull the tops and see if the bowls are full, but you would need to do that to check the accel pump input valve/jet anyway.

You 'should' have a set of spare gaskets before you pop the top one one of those.

Posted by: pilothyer Sep 30 2014, 11:36 PM

Did you check the floats in the carbs before you put them on? Have you had them apart or just bolt them on?

GENERAL INSTRUCTIONS: Float level, in mm, typically refers to the distance from the face of the carburetor top cover to the float. With the top cover held vertically (float pivot at the top) and the float tab (Lc) resting against, but not depressing the spring loaded ball in the needle valve, measure between the face of the carburetor top cover to the top of the float. On carburetor models where it is required to remove the float to replace the top cover gasket, the measurement should be made with the gasket in place to the gasket face. You need to set the floats to 10 mm closed and 32 mm opened as shown.

Posted by: URY914 Oct 1 2014, 04:30 PM

That's just a temporary location for your pump right?

You can't mount a pump higher then the bottom of the tank. Pumps are made to "push" the fuel from the tank to the engine, not to pull a vacuum and especially not up hill from the tank.

Also get rid of that glass filter.

Posted by: URY914 Oct 1 2014, 04:35 PM

My car is plumbed like this:

Tank-pump-filter, in the front of the car.

Regulator-pressure gauge-Y- carbs, in the engine compartment.

You may want to add a return line before the regulator but I don't run one.