"Assist" fuel pump on dual Weber system, Takes awhile to get fuel to the carbs when first starting after sitting Options

[mewing]

I searched and did not find this issue addressed in the last few years in the forums, but if I missed it, feel free to direct me to the post.

I think I covered it in the topic description, but when my '76 2.0 with a dual Weber system has been sitting for a week (I know, drive it every day!), it takes so much cranking to get fuel back to the carbs that I usually spray a little starting fluid over the carbs to get it to fire sooner and get the fuel moving. I have heard of adding a small (10psi or so) 12v fuel pump between the tank and the carbs, to electrically pump fuel back there so the engine will fire quicker without so much cranking and heating up the starter.

Has anyone done this with success? If so, what pump did you use?

Thanks in advance!

[URY914]

You don't have a fuel pump?

[r_towle]

(IMG:style_emoticons/default/cool_shades.gif)

[930cabman]

You don't have a fuel pump?

no worries of over pressurizing

[VaccaRabite]

By any chance do you have a bus motor with a mechanical fuel pump in your 914?
This is the only way I could imagine having to crank to fill the carb bowls. No 4/ 914 ever had the mechanical pump.

A 10psi pump for a car with dual carbs is a HORRIBLE idea. Like, horrible HORRIBLE. Car is on fire in your garage burning down your house horrible.

A proper carb pump and low pressure regulator is all you need, and should have the carb bowls filled before you start cranking if you have it wired properly.

You have work to do, and a lot more information is needed in this thread for us to help with it.

Zach

[BK911]

After your car has been sitting for a week or so...
Remove your air filters and push down on the throttle linkage.
Look to see if any gas is coming out of the acceleration jets.
These jets work off of a diaphragm and squirt out a bit of gas when you press the go pedal to compensate for the lag between the air and gas flow into the combustion chamber.
If no gas is coming out of these jets before a cold start, either the jets are clogged or your float bowls are draining somehow.
If the jets are clogged, you should notice a hesitation during acceleration.
Look for signs of gas leaking around the diaphragm cover.
The EMPIs (weber clones) on my bug needed to have gasket gunk applied on the accel pump cover to keep the float bowls from leaking out between starts.
Also I used sand paper on glass to make sure the cover was ~perfectly flat.

[GregAmy]

By any chance do you have a bus motor with a mechanical fuel pump in your 914?

Ah, I was trying to think of how it was possible that it ran AT ALL, so that makes sense.

The 914 tank is at or below the level of the carbs, so there's just no way that those should have been installed without an electric pump. Even with a mechanical pump (which is sounding a lot more likely) the fuel would drain back down to the level of the fuel tank (making it worse when low on fuel).

This sounds like a DAPO addition for sure. - GA

[jhynesrockmtn]

Whoa, for a moment I thought I was on the 356 registry

[BK911]

By any chance do you have a bus motor with a mechanical fuel pump in your 914?

Ah, I was trying to think of how it was possible that it ran AT ALL, so that makes sense.

The 914 tank is at or below the level of the carbs, so there's just no way that those should have been installed without an electric pump. Even with a mechanical pump (which is sounding a lot more likely) the fuel would drain back down to the level of the fuel tank (making it worse when low on fuel).

This sounds like a DAPO addition for sure. - GA

Fuel bowls will not drain back into tank.
Pump it a couple times and it should start right up, unless the bowls are evaporating or draining, or your accel jets are clogged.

[nditiz1]

I'm not sure I understand this unless the bus engine was an early style bus/bug engine where the mechanical fuel pump was on the top of the engine. I have never seen a setup like that as even the cooling is different (doghouse). I don't think the 76/77 type 4ish style ever had a mechanical fuel pump.

My money is on the bowls are draining and the pump takes a little to refill after sitting.

Anyone running carbs should use a CB performance rotary pump OR the existing FI pump with a PMO regulator to drop it down to 3 psi.

[brant]

Bowl draining. Modern gas sucks
My guess is that owner thought it was mechanical
But it’s probably already electric

[GregAmy]

Fuel bowls will not drain back into tank.

Didn't mean to imply that it did.

But the fuel in the lines will, and carbs will evaporate fuel over time and need to be refilled.

Bowl draining. Modern gas sucks...it’s probably already electric

Even so, an electric pump would quickly fill even completely drained bowls.

My race car with Dells has to refill the bowls each weekend because I run the bowls dry before closing it up in the trailer (to minimize the evaporation and smell). Restarting involves fuel pump on, count to five while I listen to the bowls fill, couple good accel jet pumps to prime it, and it fires right up on a few rotations. - GA

[r_towle]

Modern fuel evaporates very fast due to alchohol content.

[Spoke]

I searched and did not find this issue addressed in the last few years in the forums, but if I missed it, feel free to direct me to the post.

I think I covered it in the topic description, but when my '76 2.0 with a dual Weber system has been sitting for a week (I know, drive it every day!), it takes so much cranking to get fuel back to the carbs that I usually spray a little starting fluid over the carbs to get it to fire sooner and get the fuel moving. I have heard of adding a small (10psi or so) 12v fuel pump between the tank and the carbs, to electrically pump fuel back there so the engine will fire quicker without so much cranking and heating up the starter.

Has anyone done this with success? If so, what pump did you use?

Thanks in advance!

(IMG:style_emoticons/default/welcome.png)

I have dual webers and it does take a little while for the bowls to fill after sitting. I usually let the key in ON for a couple of seconds to start the bowls filling. Then a couple of pumps on the accelerator to get the engine going.

[PCH]

I was going to give exactly the same advice as Spoke. You can hear the fuel pump come on when you turn the key. As for the number of pumps of the accelerator, the number of times I pump it is dependent on the ambient and engine temps. I don't event have trouble starting it in cold weather-it just requires more pumps of the accelerator.

[RRietman]

I was going to give exactly the same advice as Spoke. You can hear the fuel pump come on when you turn the key. As for the number of pumps of the accelerator, the number of times I pump it is dependent on the ambient and engine temps. I don't event have trouble starting it in cold weather-it just requires more pumps of the accelerator.

on a carbed engine,sometimes, as a safety feature, the electric fuel pump will be set up to run only if the starter is cranking or if there is oil pressure. I have set up a couple engines like this. he might be dealing with a similar set up---- then there is the ethanol not helping.

[mewing]

I was going to give exactly the same advice as Spoke. You can hear the fuel pump come on when you turn the key. As for the number of pumps of the accelerator, the number of times I pump it is dependent on the ambient and engine temps. I don't event have trouble starting it in cold weather-it just requires more pumps of the accelerator.

on a carbed engine,sometimes, as a safety feature, the electric fuel pump will be set up to run only if the starter is cranking or if there is oil pressure. I have set up a couple engines like this. he might be dealing with a similar set up---- then there is the ethanol not helping.

Thanks to all for the responses. I didn't get notifications so I didn't realize so many people had responded with advice.

I don't hear an electric pump with just the key on (like I do in my '55 Chevy with a high-volume external fuel pump), so it may be correct that it only runs while the engine is cranking. I will check the bowls, as I think them draining certainly makes sense.

I will report back with what I find. Thanks again!