TheSamba.com :: View topic - Fuel pump 72-74 type 4 engine?

Wed Nov 18, 2009 10:12 am

I am normally on the Thing forum but I am considering a Type 4 engine upgrade with the DTM cooling set up.

I would like your kind advice about the mechanical fuel pumps on these beasts. Can you even get them and the associated parts? Can you get them new or rebuilt or are only used one s available…? And if so where do I go to get them…? Should I just forget this quant setup and do an electric one…. I like the simplicity of a mechanical fuel pump but if it is going to be a headache then I will just go electric…

Your opinions would be kindly accepted.

ThanX 8)

http://jeffgilleland.googlepages.com/my_air-cooled_cars

Wed Nov 18, 2009 10:59 am

expensive to replace a mechanical pump on this thing.....

http://www.germansupply.com/home/customer/product.php?productid=16620&cat=&page=3

http://www.germansupply.com/home/customer/product.php?productid=16622&cat=&page=3

I would say most people use the 3.5 psi CB electric pump and ideally use a good regulator with it and wired using a relay not on the + side of the coil.

http://www.cbperformance.com/catalog.asp?ProductID=577

Wed Nov 18, 2009 5:27 pm

Spot on, Randy. My pump didn't 'fail' exactly as much as became so leaky as to be dangerous. Brazilian crap.

I'm using an electric pump and a Holley low pressure regulator.

Be damn careful about the pump you get. I paid nearly $100 for one (cheapest I could find) and later found out it was putting out 8+PSI. Hence the regulator.

The facet style pumps rattle like a bitch too, so you'll need vibration damping. On a bay I can get away with mounting it somewhere on the engine / trans assembly as the mass of the drivetrain and the rubber mounts essentially silences the vibration noise transmitted. It can still kind of be heard from outside though.

On my S beetle I had a facet mounted up back with no issues. Probably a lot better off mounting it up front on a beetle or thing though.
Definitely run it through its own relay and fuse. I cannot stress this enough. I had a pump go short circuit. The fuse saved the loom. Damn shame too. I liked that pump. It was an electric diaphragm pump. Pretty much had the guts of a mech pump actuated by a solenoid. At idle the pump would pulse at a bit under 1hz like a heartbeat. If I could find another I would get it.

Wed Nov 18, 2009 6:16 pm

Randy in Maine wrote:
I would say most people use the 3.5 psi CB electric pump and ideally use a good regulator with it and wired using a relay not on the + side of the coil.

http://www.cbperformance.com/catalog.asp?ProductID=577

Why a regulator Randy? I've installed a few of those and am currently running one on the 72, the pressure is dead on every time I check it (and I check it alot being a skeptic an all :wink: ) unlike alot of the other pumps mentioned.
I've gotta say it's absolutely the best aftermarket pump I've dealt with, quiet and reliable.

Wed Nov 18, 2009 6:38 pm

I am not a carb guy, but was under the impression that a fair number of them like to see lower fuel pressures ~ <2.0 psi.

I will certainly defer to someone who knows better though.

Wed Nov 18, 2009 7:21 pm

They do prefer low pressure, but that rotary pump is somehow regulated internally right out of the box and so far always makes the 2.5 PSI (or whatever pressure the particular model spec's) , most of those solenoid pumps make more or are very inconsistant even though they claim to be constant pressure. If your pump clicks you need a regulator. Same with the big Holley rotary pumps that look like a remote oil filter with wires, way too much pressure for any carb on a VW unless you are a serious drag racer.

Wed Nov 18, 2009 7:31 pm

The Facet pump I have is rated at <4#. Worked well with the solexes but now I have Weber 40's ready to bolt on. Hope this is low enough for these.

Thu Nov 19, 2009 10:04 am

Thank you Volks for that information, I will defiantly not be using a mechanical fuel pump. 8)

Thu Nov 19, 2009 10:18 am

busdaddy wrote: Randy in Maine wrote:
I would say most people use the 3.5 psi CB electric pump and ideally use a good regulator with it and wired using a relay not on the + side of the coil.

http://www.cbperformance.com/catalog.asp?ProductID=577

Why a regulator Randy? I've installed a few of those and am currently running one on the 72, the pressure is dead on every time I check it (and I check it alot being a skeptic an all :wink: ) unlike alot of the other pumps mentioned.
I've gotta say it's absolutely the best aftermarket pump I've dealt with, quiet and reliable.

Randy and Bdaddy, what relay do you recommend? I just purchased a pump from CBP, but they do not carry a proper relay for it.

Thu Nov 19, 2009 10:51 am

peaceful warrior wrote: busdaddy wrote: Randy in Maine wrote:
I would say most people use the 3.5 psi CB electric pump and ideally use a good regulator with it and wired using a relay not on the + side of the coil.

http://www.cbperformance.com/catalog.asp?ProductID=577

Why a regulator Randy? I've installed a few of those and am currently running one on the 72, the pressure is dead on every time I check it (and I check it alot being a skeptic an all :wink: ) unlike alot of the other pumps mentioned.
I've gotta say it's absolutely the best aftermarket pump I've dealt with, quiet and reliable.

Randy and Bdaddy, what relay do you recommend? I just purchased a pump from CBP, but they do not carry a proper relay for it.
Germansupply has a nice relay kit that uses a relay from a rabbit, it senses ignition activity.
I went with a pressure switch teed into the oil pressure, same end result with the bonus of low pressure shutdown :wink:

Thu Nov 19, 2009 12:28 pm

How did you hook up that pressure switch? I mean the thread ends? Any photos?

Thu Nov 19, 2009 12:35 pm

Sorry, no pics yet (took em, just can't find em) and bus is stored for the winter now.
I used a M10X1.0 to 1/8 "NPT adaptor and an 18" grease gun/hydraulic hose at the case end and a 1/8" brass + fitting on the roof of the engine compartment, enough holes for the pressure switch, OG idiot light switch and sender for the pressure gauge.

Thu Nov 19, 2009 12:40 pm

busdaddy wrote: Sorry, no pics yet (took em, just can't find em) and bus is stored for the winter now.
I used a M10X1.0 to 1/8 "NPT adaptor and an 18" grease gun/hydraulic hose at the case end and a 1/8" brass + fitting on the roof of the engine compartment, enough holes for the pressure switch, OG idiot light switch and sender for the pressure gauge.

So you used hard line on both sides? I'm sure I can get the parts I need here in town. I was planning on running hardline all the way except in those areas that soft line is necessary.
BTW, CBP recommended mounting the pump under the tank, instead of up high in the engine compartment, as some have done. They stated that it would put too much strain on the pump if mounted up high.
Any response to that. I am trying to decide the best way to go!

Thu Nov 19, 2009 12:42 pm

busdaddy wrote: If your pump clicks you need a regulator.

Not necessarily true...I have had a "box" style, "clicking" pump that came with Bessie for 6 years...I ran it with the stock 32/34 solexes, the aftermarket 34 solexes, and now it is pumping into my Holey/Weber, and no issues with too much pressure. It's rated at 3.5 psi, according to the sticker, and I dangerously run it off the coil.

Come to think of it, my BN4 pump has a unique click...

Thu Nov 19, 2009 12:56 pm

The clicking is due to the style of pump, not for the lack of a relay. The CB pump (rotary style) is not much of a sucker, more of a pusher, so gravity fed fuel from the tank as in placing it somewhere under or lower than the tank is ideal. The Facet is a diaphram style of pump and is a sucker, it will draw fuel, or is perfectly happy having gravity fuel. The safety factor is having the pump out of the engine compartment, the relay is for safety.

I use a double relay set up, here is a link to the set up.
http://www.paultaylorimaging.com/VW/Fuel_Pump_Relays/Fuel_Pump_Relays.htm

Thu Nov 19, 2009 1:31 pm

peaceful warrior wrote: busdaddy wrote: Sorry, no pics yet (took em, just can't find em) and bus is stored for the winter now.
I used a M10X1.0 to 1/8 "NPT adaptor and an 18" grease gun/hydraulic hose at the case end and a 1/8" brass + fitting on the roof of the engine compartment, enough holes for the pressure switch, OG idiot light switch and sender for the pressure gauge.

So you used hard line on both sides? I'm sure I can get the parts I need here in town. I was planning on running hardline all the way except in those areas that soft line is necessary.

No hard line in the oil pressure setup, just short brass fittings and the flex hose running up to where I mounted the senders, IIRC the M10 adaptor had a female 1/8NPT on one end and a flare cone on the male metric end I had to file off, came from the brass brake and fuel fitting display at the FLAPS but any jobber supply outfit should have something similar. The 1/8NPT will thread into the case as is but the threads really don't match perfectly.
I mounted the pump under the tank at the top of the sloping firewall and used hose from it to the carbs. Hard lines are on the list but that 1/2 hour job turned into a day and a half as it was and I just wanted to go camping.

73Kombi wrote: busdaddy wrote:
If your pump clicks you need a regulator.

Not necessarily true...I have had a "box" style, "clicking" pump that came with Bessie for 6 years...I ran it with the stock 32/34 solexes, the aftermarket 34 solexes, and now it is pumping into my Holey/Weber, and no issues with too much pressure. It's rated at 3.5 psi, according to the sticker, and I dangerously run it off the coil.

Come to think of it, my BN4 pump has a unique click...

You're a lucky man, older domestic manufactured pumps generally put out a fairly constant pressure, the newer ones made overseas? not so much.
The pump on your heater works on a different principal and infact produces no pressure, but it does provide an exact volume of fuel with each timed click :wink:
As for running it off the coil? suit yourself, I sleep better at night knowing my pump will shut off if engine issues arise and there's no extra load on my ignition switch or the 30' of wire connected to it.