Aftermarket Fuel Pump Mounting Issues

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whc03grady
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Location: Livingston Montana
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Aftermarket Fuel Pump Mounting Issues

Post by whc03grady » Mon Jul 07, 2014 8:14 am

Ludwig's electric fuel pump often made such a racket where it used to be mounted that Colin and I moved it atop the transaxle in 2010 or 2011 or sometime. It made a lot less noise there (or, better, its noise was much less readily-transmitted to the cabin from there).

Last weekend we found ourselves idling at the shoulder on an onramp in SW Montana for a diaper change, maybe for 10 minutes. Everyone dry, I accelerated to get back in the flow when the engine gave me a brief but definite hiccup, toward the top of 3rd gear (ca. 47-50 mph). It instantly recovered so I blamed it on bad gas [Question: Is there such a thing? I mean, the gas wasn't old, but maybe it was an off-brand or batch? Maybe I put in the wrong octane? I always go for the cheapest, the 87 or whatever.] There were no other problems the rest of the hundred or so miles home.

Fast forward to this weekend. On the way home, on the hottest day of the year so far (low 90s), same situation: idled for awhile during a pit stop, stumbled while getting up to speed. Except this time it was much more pronounced right off the bat. It stumbled at the top of each gear, excepting 4th which I didn't get into; I pulled over to see if it was overheating. It didn't seem to be; the fan shroud was plenty warm but not exceedingly so. I pulled out the dipstick with no trouble. After sitting for a while I gave it another go and after a couple hiccups it seemed to resolve itself so we kept on barreling toward home. It was running fine, 65-70 mph, until I had to downshift to get over the last major pass of the trip. It stumbled like crazy and this time I couldn't limp it forward.

Terrified that I was cooking this pretty-new engine, I went out back but again, it didn't feel or smell hot. Thinking the stumbling felt as though we were simply running out of gas, I went to look at the fuel filter(s). Well well well. The first thing I see is that the fuel line coming out of the tank is rubbing on the axle, which has worn through a good part of the cloth. "Why is it hanging that low anyways?" I thought. Because the fuel pump has liberated itself from its perch atop the transaxle, that's why. The only things holding it on were the fuel lines and its wiring.

Not of a mind to wait on a busy interstate shoulder for it to cool down enough to really crawl underneath and wrestle with it (again, on a busy interstate shoulder), especially with the family, I made the call to have Ludwig make it the rest of the 38 miles home on the hook (flatbed actually).

I'm not sure why I posted this since I don't have any questions yet (except the bracketed one above). I suppose I did because I'll have some after I take a closer look at everything this week.
Ludwig--1974 Westfalia, 2.0L (GD035193), Solex 34PDSIT-2/3 carburetors.
Gertie--1971 Squareback, 1600cc with Bosch D-Jetronic fuel injection from a '72 (E brain).
Read about their adventures:
http://www.ludwigandgertie.blogspot.com

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Amskeptic
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Re: Aftermarket Fuel Pump Mounting Issues

Post by Amskeptic » Fri Jul 11, 2014 10:22 am

whc03grady wrote:Ludwig's electric fuel pump has liberated itself from its perch atop the transaxle. The only things holding it on were the fuel lines and its wiring.
How did this liberation affect the hiccupping behavior?

What were the fasteners holding the pump to the transaxle? 13mm bolt/nuts? Did the pump have a belly band? Still there?

Solution would be to double-nut the bolt (better than any lockwasher).
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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whc03grady
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Re: Aftermarket Fuel Pump Mounting Issues

Post by whc03grady » Fri Jul 11, 2014 9:27 pm

Amskeptic wrote:How did this liberation affect the hiccupping behavior?
The hiccuping became severe enough that the vehicle was undrivable. Was the pump bouncing around, pulling on its own wiring, intermittently breaking a circuit and shutting off? I don't know. Did the hiccuping have anything to do with the fuel line rubbing on the axle, maybe making the fuel really hot (I'm grasping at straws here)? I don't know. It didn't leak any gas, I know that much.
Amskeptic wrote:What were the fasteners holding the pump to the transaxle? 13mm bolt/nuts? Did the pump have a belly band? Still there?
I don't remember, honestly. The pump didn't have a belly band, as it is not the cylindrical kind; it's one of those boxes.
Amskeptic wrote:Solution would be to double-nut the bolt (better than any lockwasher).
I'll get under it tomorrow or Sunday. I'm thinking I'll just put it back where it was for the time being. I have one of those cylindrical ones, that I recall you remarking was a better pump in any case. Maybe we'll put it on in August, depending on what you think of my list. (Note to self: pm Colin my list.)
Ludwig--1974 Westfalia, 2.0L (GD035193), Solex 34PDSIT-2/3 carburetors.
Gertie--1971 Squareback, 1600cc with Bosch D-Jetronic fuel injection from a '72 (E brain).
Read about their adventures:
http://www.ludwigandgertie.blogspot.com

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whc03grady
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Location: Livingston Montana
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Re: Aftermarket Fuel Pump Mounting Issues

Post by whc03grady » Mon Jul 21, 2014 5:26 pm

One of the ears on the old pump had broken off.
Image

Rather than see what kind of life the old pump could live as an amputee, I think I should go with this never-used one I have hanging around. My engine builder sent it with the engine, which he knew would be carbureted, and I think you signed off on it as well, amskeptic, so I think it'll work.
Image

However. Like the old, the new doesn't have the correct nipple sizes for the hoses from the tank and to the carbs. The old pump had the correct size on its inbound side, but it was too large downstream. So we stepped it down with a fuel filter. The new pump is too large on both sides. Here's my beautiful hand-drawn diagram of the situations (suitable for framing).
Image

Questions: Where to put this new pump? I'm leaning toward the spot the old one used to live, before it was relocated above the transaxle. That support that runs perpendicular to the frame rail, going up and over the trans/engine mating. Or, the angled beam connecting the torsion bar housing to the frame rail. Any better spots?
Should I or shouldn't I just chop off the old pump's wiring, fit some spades, and use it? If not, what gauge am I looking for?
Ludwig--1974 Westfalia, 2.0L (GD035193), Solex 34PDSIT-2/3 carburetors.
Gertie--1971 Squareback, 1600cc with Bosch D-Jetronic fuel injection from a '72 (E brain).
Read about their adventures:
http://www.ludwigandgertie.blogspot.com

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Amskeptic
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Re: Aftermarket Fuel Pump Mounting Issues

Post by Amskeptic » Tue Jul 22, 2014 9:19 pm

whc03grady wrote: Where to put this new pump?
Should I or shouldn't I just chop off the old pump's wiring, fit some spades, and use it? If not, what gauge am I looking for?
You have full discretion here.
Mounting Think: rock blasts/vibration/chafing/access/heat-sources-nearby, etc.
Wiring Think: amperage/resistance/heat/corrosion
Quality Think: is it pretty? sensible? elegant? robust? thoughtfully executed?
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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whc03grady
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Location: Livingston Montana
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Re: Aftermarket Fuel Pump Mounting Issues

Post by whc03grady » Tue Jul 22, 2014 10:48 pm

Amskeptic wrote: Wiring Think: amperage/resistance/heat/corrosion
I'm reasonably confident I can handle the other two Thinks, but have no frame of reference for this one. I know I probably shouldn't use speaker wire, and that's it.
Ludwig--1974 Westfalia, 2.0L (GD035193), Solex 34PDSIT-2/3 carburetors.
Gertie--1971 Squareback, 1600cc with Bosch D-Jetronic fuel injection from a '72 (E brain).
Read about their adventures:
http://www.ludwigandgertie.blogspot.com

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Amskeptic
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Re: Aftermarket Fuel Pump Mounting Issues

Post by Amskeptic » Wed Jul 23, 2014 10:23 pm

whc03grady wrote:
Amskeptic wrote: Wiring Think: amperage/resistance/heat/corrosion
I'm reasonably confident I can handle the other two Thinks, but have no frame of reference for this one. I know I probably shouldn't use speaker wire, and that's it.
It is pretty low amperage, 18-22 gauge is utterly fine.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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