Weber DGV, cont'd... Electric fuel pump install

[tosoutherncars]

Well, my DGV and higher compression have upped the power, but I'm getting a stumble on accelleration... sometimes. And the vendor that sells DGVs online is adamant that they will not run well on either a) mechanical pumps with pressure regulators, or b) Facet-style electric pumps.

So, time to install the Carter... model 4070, rotary vane-style, high volume, low pressure. This, and no regulator, is *supposed* to be the ideal setup. Time will tell.

Here's the rear bulkhead, which is where I'm mounting the pump.

On the right is the return line from the engine bay, which I'm no longer using. I disconnected the fittings, both here and at the condensor (right side of trunk) and removed the piece that runs over the axle.

Oh, you can see that there is a ridge running across the bulkhead. there's a captive bolt, originally used to hold down those two fuel lines. That's what I'm using for the top bolt to hold on the Carter.

Here's what I'm using... the Carter 4070

Thankfully, my local big box car parts place had slightly smaller fuel fittings in their nuts & bolts bin. Smaller is on the pump, original beside it for comparison. Oh, and a clear filter I'll be installing... somewhere. (?)

And here it is in all its glory. Because the top bolt is on the ridge, I slipped a large nut between the cage and the bulkhead, just to keep it plumb. A dab of sealant, fender washer and lock washer on each.

Impossible to tell from the photo, but the way the mounting kit fits, the bolts, even when fully tight, only squeeze the rubber donuts very loosely. With light pressure, you can move the pump slightly back and forth.

And the plan, roughly, is this...

Tank to 'IN' side, 'OUT' side to (former) vent line. Vent line exits...

...right behind the carb. Installed a spacer to raise it up a bit, and it's plumbed in already. Might put the filter up here. Frankly, I don't think I have that much crap in my tank. And I think I'd rather replace a fuel pump than rebuild that carb!

 

[tosoutherncars]

Oh... and I pulled the mech. fuel pump, took off the hoses, removed the actuator arm, and reinstalled it. If this all works, I'll eventually make a block off plate, but for now the pump body should work just fine.

 

[jcatnite]

Looks good Duncan. That is a good location. So with this pump you can dial the pressure down to less than 3.5psi? When I move mine I might ditch the one I have and go with the carter if it works out for you.
JC

 

[jlaird]

nice job.

 

[PAUL161]

The "stumble" your talking about, seem to be a trade mark of the DGV carb. I had one on the 79 and it did the same thing. I had one on my Jeep and it did the same thing. I haven't heard of anybody solving the problem. To me it seems like it would be the acceleration pump inside the carburettor. To much or to little fuel?
I use the one off the 79 as a paper weight! So to speak.

 

[regularman]

That is the kind of fuel filter I used. I would recommend it to anyone. Easy to see what is in it and very easy to remove and clean out. With that tempered glass and o ring seals it should last forever.

 

[tosoutherncars]

Looks good Duncan. That is a good location. So with this pump you can dial the pressure down to less than 3.5psi? When I move mine I might ditch the one I have and go with the carter if it works out for you.
JC

No, the pump is preset. I suppose it will have lost a bit of pressure by the time it hits the carb. But I think the characteristics of vane pumps, rather than pulsed pumps, are the big difference here. With a Facet, or the original mechanical pump, once the carb bowls have been filled... they just keep pumping, right? They have no choice. As opposed to vane pumps, which keep spinning, but essentially without pumping? Anyway, here's one of the vendors...

https://www.racetep.com/webfuelspark.html#webfuel

The "stumble" your talking about, seem to be a trade mark of the DGV carb. I had one on the 79 and it did the same thing. I had one on my Jeep and it did the same thing. I haven't heard of anybody solving the problem. To me it seems like it would be the acceleration pump inside the carburettor. To much or to little fuel?
I use the one off the 79 as a paper weight! So to speak.

Absolutely, it's a trademark problem, but there are a couple of well-known reasons. Air leaks, either at the manifold-to-head or elsewhere... And failure to set the carb up lean enough at idle. Tony (the Autoist) has a good webpage to discuss the former. I posted some links to a discussion of the latter, in previous threads.

I had mine set up pretty well before I blew my engine, requiring a rebuild! :frown: Now it's just a matter of dialling it in again, with higher compression added to the equation.

 

[George Zeck]

Duncan -

I just installed the DGV and have installed the facet pump in the back of the car along with a holley regulator. All runs fine. Your absolutely right about the spacer. I even added a fuel line shink wrap to keep the heat off the incoming fuel line. Mine is new. For the price of a fuel pump - a good move.

Hope all works out.

 

[tosoutherncars]

OK, here we go... all plumbed in, and ground strap on. Still haven't run the power wire yet.

Note the arrow on the pump head, so I don't forget which way everything's going... :wink:

Started the wiring at the front, getting switched power from the ignition. Fusible link to start. This would be a quick security feature, when leaving the car somewhere deserted... pull out the fuse, and would-be robbers would only get a block or two!

This will all be tied back up when I'm done, of course. The black /grn / black you can see near the shifter is the powered switch for the electric fan conversion. Works well, just have to finish mounting it... probably in the console.

Power tomorrow, and maybe a drive.

 

[jbuffalo]

Mg Midget 1500-I see people are using the vent line connecting it to the installed electric fuel pump to run fuel to the carb, is this the way to go? Jim

 

[Morris]

Duncan,

Please consider using a relay to direct power to your pump. Your ignition switch can barely manage the current it has to carry without the addition of the pump. And ignition switches are a bear to replace. You can use the wire from ignition as you have it to switch the relay, and take power for the pump where the alternator and battery bolt to the starter relay. This will also give you a much stronger and more reliable signal to your pump. Just keep a spare relay in your care for those worst case scenario moments.

 

[tosoutherncars]

Dammit... Yes, I'm sure you're right Morris. I relayed my fan and horn, but not the pump. I'll grab a kit the next time I'm at the store.

FWIW... works fine, perhaps a little louder than I expected, but not audible once the engine is running. Seems to work great, as far as keeping up with supply, without overwhelming the carb (I've taken off the pressure regulator.)

 

[Woodie]

Duncan just to let you know,, the Cheshire cat is holding a british car day this weekend.. it is sat 1pm-4pm.
https://www.cheshirecatpub.com/events.htm
they are at Carp rd and Richardson side rd, exit queensway at carp rd turn right at the dump and the first light is it...I will try to make it, but we have a family gathering that day

 

[Morris]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]perhaps a little louder than I expected,[/QUOTE]

If you can mount some kind for rubber isolation between the pump and the car, it will help make things much quieter. My pump uses a clamp style mount. I wrapped the pump with an old mouse pad before placing it in the clamp. This makes the pump barely audible.

 

[tosoutherncars]

Oh, it's suspended by rubber grommets, there's no metal-to-metal. Once the car is running, it's inaudible... I'd say it's about as loud as the pump in my modern VW. (Just more noticeable due to the lack of roof!)

 

[tosoutherncars]

So, my 'DGV stumble' seems to be gone... but I have a distinct miss throughout the rev range. Will investigate tomorrow... swap out spares until I find the culprit. Thankfully I've got extras of just about everything on hand: coil, wires, rotor, plugs, cap, even a spare (new) dizzy. I know it's not very scientific, but I plan on swapping everything one part at a time, until the stutter disappears.

Once I've got rid of the stutter, I'll be able to dial in the carb more accurately, and report on performance.

Today I:

- finished flushing the rad,
- refilled with about 10% coolant mix and some Water Wetter
- hollowed out my thermostat*

*(I don't have a heater, or run the car in cold weather, so I'm not really worried about it. I *may* switch back once I figure out the root of my cooling problems.)

 

[tosoutherncars]

Mg Midget 1500-I see people are using the vent line connecting it to the installed electric fuel pump to run fuel to the carb, is this the way to go? Jim

:shocked: Someone else?!? Darn, I thought I'd come up with a real innovative mod there! :frown:

 

[jcatnite]

Duncan,
I think you did the same thing I did. I learned yesterday that the two inlets to the DGV aren't the same. One has a restrictor in it with a very tiny orifice for a fuel return line. On my carb that is the outboard connector (same as where your fuel line is connected). Weber told me that using the return connection will starve the fuel bowl. I ran with it connected there a long time (18 months). I'm not sure it it really matters. I'm down for the count right now. Ignition switch is ruined. I have to hot wire it to tinker on it. I think I have the weber set up a little better but can't drive it to confirm. It certainly idles better. They also told me that the fuel leakage from the the secondary shaft after shutdown was due to high float level and rich condition. I have a bunch of info from them that I can share if you are interested.
JC

 

[tosoutherncars]

Interesting!! I'm pretty sure it was already plumbed in there when I got it, but might be a case of DPO. I'll certainly double-check... and yes, the more info I can get my hands on, the better!

 

[RonMacPherson]

Congratulations on the pump installation. Have you considered rotating the pump to straighten out the hosing? I don't believe the pump needs to be in a "true" upright position. Things may have changed, but I mounted the early blue Carter at about a 60 degree angle to straighten out the hoses on my 6, course this was back in the 80's. As long as the pump level is below fuel level doesn't matter which direction is up. And for noise insulation I got some of the MB aircleaner mounts(little studs with rubber biscuits in the middle) as isolators.

A fuel pump relay is agood thing. I recommend safety wiring it into the oil pressure circuit.