Mech.Fuel Pump - Pressure test at Colin's request on O72 Bus

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Oregon72
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Post by Oregon72 » Wed Aug 04, 2010 4:57 pm

Latest post of the previous page:

I'm planning on going this route - even though it barely makes sense to me how to put this in action

http://www.paultaylorimaging.com/VW/Fue ... Relays.htm

Apparently this way incorporates two relays - one that runs the pump while cranking and the other that runs the pump while the engine is actually running.

I'm going to be leaving the mechancal fuel pump in place and loop a 6 inch piece of fuel line to the inlet and outlet for now. That will serve as my backup to limp home if need be. It is my understanding that removing the mech pump and pushrod and putting in a block off plate can cause an internal oil leak of sorts because there is a gallery that lubricates the pushrod.

I'll need to figure out where to tap into the power and such - lets schedule a time as I could use help if you've done this type of thing before. Electrical stuff has never been my strong suit.
-'72 Westy-

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dtrumbo
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Post by dtrumbo » Wed Aug 04, 2010 5:11 pm

That diagram is similar to what VW designed into the 'double relay' used in their fuel injection vehicles for that exact application. One thought. I would use the appropriate size wire and NOT install the fuses as depicted in the diagram. VW doesn't fuse the ignition or fuel pump wiring and I tend to agree. The last thing you need is your bus dying at a very inopportune moment because a fuse blew. This is just one opinion, I'm open to discussion on the topic.

Fuses or not, you can do this. The relays, wire and connectors are cheap and easy to get at your FLAPS. Sounds like you've got good, local help too. Let us know how it goes.
- Dick

1970 Transporter. 2015cc, dual Weber IDF 40's
1978 Riviera Camper. Bone stock GE 2.0L F.I.
1979 Super Beetle convertible.

... as it turns out, it was the coil!

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Amskeptic
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Post by Amskeptic » Wed Aug 04, 2010 9:12 pm

dtrumbo wrote:That diagram is similar to what VW designed into the 'double relay' used in their fuel injection vehicles for that exact application. One thought. I would use the appropriate size wire and NOT install the fuses as depicted in the diagram. VW doesn't fuse the ignition or fuel pump wiring and I tend to agree. The last thing you need is your bus dying at a very inopportune moment because a fuse blew. This is just one opinion, I'm open to discussion on the topic.

Fuses or not, you can do this. The relays, wire and connectors are cheap and easy to get at your FLAPS. Sounds like you've got good, local help too. Let us know how it goes.
I would most certainly fuse the pump. Absolutely.

VW does fuse the FI pump through the B+ to 88y (?) circuit.

Oregon72, you can run the pump itself from the heater blower Big Red Wire AFTER the 16 amp fuse. Splice in and send it to #30 on your generic relay. #87 goes to the pump itself. #86 is control relay signal wire that you can patch off the blue wire at the voltage regulator-to-Alt warning lamp. #85 is grounding.

I would not waste the time to do a starting relay. Your float bowls have more than enough fuel to start the engine for months. If you ever need to prime the pump, just hot wire from battery to #87 on your fuel pump relay.
Colin
BobD - 1978 Bus . . . . . . . . . . .111,130 miles
Chloe - 1970 bus . . . . . . . . . . . 206,787 miles
Naranja - 1977 Westfalia . . . . . 94,615 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 72,990 miles

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Oregon72
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Post by Oregon72 » Wed Aug 04, 2010 9:32 pm

OK - how about this question - where do you all have your electric fuel pumps mounted. In the engine compartment makes the most sense because it is cleaner and dryer and easier to check and access but potentially more fire hazard. Under the bus near the fuel tank outlet is more dirty and wet and harder to access but would seem safer from a fire aspect. ????

Wouldn't the second relay for cranking be useful if the bus was to ever run out of gas? I guess I have some things to think about here.
-'72 Westy-

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Post by Westy78 » Wed Aug 04, 2010 9:42 pm

Oregon72 wrote:OK - how about this question - where do you all have your electric fuel pumps mounted. In the engine compartment makes the most sense because it is cleaner and dryer and easier to check and access but potentially more fire hazard. Under the bus near the fuel tank outlet is more dirty and wet and harder to access but would seem safer from a fire aspect. ????

Wouldn't the second relay for cranking be useful if the bus was to ever run out of gas? I guess I have some things to think about here.
Factory FI pumps are mounted on the frame rail right in front of the drivers side rear wheel. Make sure to isolate the pump with some rubber mounts or it'll make a racket.
Chorizo, it's what's for breakfast.

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Amskeptic
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Post by Amskeptic » Wed Aug 04, 2010 9:46 pm

Oregon72 wrote:OK - how about this question - where do you all have your electric fuel pumps mounted. In the engine compartment makes the most sense because it is cleaner and dryer and easier to check and access but potentially more fire hazard. Under the bus near the fuel tank outlet is more dirty and wet and harder to access but would seem safer from a fire aspect. ????

Wouldn't the second relay for cranking be useful if the bus was to ever run out of gas? I guess I have some things to think about here.
Mount the pump under the tank like the rules tell you. These pumps are a lot happier pushing than sucking. There are many options for mounting under there. I do tank-filter-pump-regulator-carbs. That would be so cool if your engine would be able to pull up to 4,000 rpm once more.

Do NOT run out of gas for cryin' out loud. If you did run out of gas, you would still have enough accelerator pump to fire up the alternator and thus fuel pump. But if you didn't, you'd get your little piece of wire and run it from the battery to the #87, run it for ten seconds, start the engine.
Colin
BobD - 1978 Bus . . . . . . . . . . .111,130 miles
Chloe - 1970 bus . . . . . . . . . . . 206,787 miles
Naranja - 1977 Westfalia . . . . . 94,615 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 72,990 miles

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dtrumbo
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Post by dtrumbo » Thu Aug 05, 2010 6:36 am

Amskeptic wrote:VW does fuse the FI pump through the B+ to 88y (?) circuit.
Nope. Double relay 88y is directly connected to the battery. No fuse. I'm still open to debate, however.
- Dick

1970 Transporter. 2015cc, dual Weber IDF 40's
1978 Riviera Camper. Bone stock GE 2.0L F.I.
1979 Super Beetle convertible.

... as it turns out, it was the coil!

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Amskeptic
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Post by Amskeptic » Sun Aug 08, 2010 11:00 am

dtrumbo wrote:
Amskeptic wrote:VW does fuse the FI pump through the B+ to 88y (?) circuit.
Nope. Double relay 88y is directly connected to the battery. No fuse. I'm still open to debate, however.
Later VWs circuit breaker the circuit, or fusible link the circuit.

Here's the mystery for me. I do not see fuse in ignition coil #15 circuit from ignition switch which gets its juice from the upriver side of the fuse.
That means there is no fuse-blow to stall the engine. Right? OK, I had a choke wire fall off the Road Warrior and ground against the throttle link. It would only temporarily stall the engine. I felt circuit breaker behavior.

How does VW protect that circuit? Later cars all seem to have noticeable fusible links.
Does VW use the relay itself as a fuse?
:withstupid:
Colin
BobD - 1978 Bus . . . . . . . . . . .111,130 miles
Chloe - 1970 bus . . . . . . . . . . . 206,787 miles
Naranja - 1977 Westfalia . . . . . 94,615 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 72,990 miles

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dtrumbo
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Post by dtrumbo » Mon Aug 09, 2010 6:28 am

Amskeptic wrote: Does VW use the relay itself as a fuse?
From my experience with my Beetle, I would have to say yes.

When I bought the car, the wires going to the AAR were poorly routed, became chaffed by the alternator belt and were shorted together. What finally stopped the current flow was the burned traces (aka fuse) on the circuit board inside the double relay.

I don't have an explanation for the Road Warrior's behavior other than the wire shorting to the throttle link was itself intermittent?
- Dick

1970 Transporter. 2015cc, dual Weber IDF 40's
1978 Riviera Camper. Bone stock GE 2.0L F.I.
1979 Super Beetle convertible.

... as it turns out, it was the coil!

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Oregon72
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Post by Oregon72 » Wed Aug 11, 2010 4:15 pm

So I've finally completed the install of my Carter rotary pump and converting my system from mechanical fuel delivery to electric. The mechanical delivery was way more simple no doubt. I went to the trouble of using correctly colored wires and shrink tubed groups of wires where it made sense. Took me several hours to do this and was in the garage way too late last night. Most of the work was trying to figure out where to mount the fuel pump with the metal filter that came attached to it. Finding a flat surface near the tank with a run of length such that the fuel lines don't get pinched took some thinking. I finally determined that I would just mount it above the transmission. One tricky thing is the fuel pump has larger inlets and outlets than the normal dual carb fuel line size. I put in another fuel filter after the pump to step down the size. This one is in addition to the metal one that is before the pump and came with it. Is it OK to have a filter before and after the pump.


Location - this may change, but for now I'm fine with it.
Image

Image

Disabled mechanical pump by connecting inlet and outlet together
Image

At the lucky lab on Monday, Tristessa set me up with the perfect relay to take care of this conversion and a great diagram that even a dummy could understand. This relay takes power directly from the battery via a 7.5 amp in-line fuse. The relay takes signal from the coil.

The relay had no way to mount, so I got a thin piece of flat tin and JB Welded the relay to it so I could mount it to the firewall next to the voltage regulator. Kinda looks like it was meant to be there. If the relay ever goes bad, I'll have to make another mount, but this is nice and clean looking.

Image

Image

Here is the in-line fuse I used for power supply from the battery.

Image

Sooooo how did it run?? Seems a little bit better, nothing huge or drastic as far as improvement, but I'm still feeling a little bit of pulsing or maybe I'm insane and it is just bumpy pavement. Anybody have a mile long sheet of glass I could drive on just to verify???

I"ll be testing the fuel pressure with my harbor freight gauge to see if my pressure has gone up or not.
-'72 Westy-

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Amskeptic
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Post by Amskeptic » Thu Aug 12, 2010 7:25 am

Oregon72 wrote:So I've finally completed the install of my Carter rotary pump
Tristessa set me up with the perfect relay to take care of this conversion and a great diagram that even a dummy could understand. This relay takes power directly from the battery via a 7.5 amp in-line fuse. The relay takes signal from the coil.
If I am reading this correctly, taking the signal from the coil defeats the entire purpose of a relay.

You need a signal that "stalls with the engine". A coil signal will still dump gasoline under pressure all over you and your wounded passengers at the bottom of the gorge.

Take the fuel pump signal from the alternator blue wire as suggested previously, and have a handy little hot wire for the two times a year you need to energize the pump to prime the carburetors.
Colin
BobD - 1978 Bus . . . . . . . . . . .111,130 miles
Chloe - 1970 bus . . . . . . . . . . . 206,787 miles
Naranja - 1977 Westfalia . . . . . 94,615 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 72,990 miles

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hambone
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Post by hambone » Thu Aug 12, 2010 7:31 am

Did you remove the pump actuator rod? Otherwise it's just gonna keep pumping to nowhere. Doesn't matter I guess, you disconnected the fuel source.
Can you still get rebuild kits for type4 pumps?
http://greencascadia.blogspot.com
http://pdxvolksfolks.blogspot.com
it balances on your head just like a mattress balances on a bottle of wine
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Amskeptic
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Post by Amskeptic » Thu Aug 12, 2010 7:42 am

hambone wrote:Did you remove the pump actuator rod? Otherwise it's just gonna keep pumping to nowhere. Doesn't matter I guess, you disconnected the fuel source.
Can you still get rebuild kits for type4 pumps?
Oregon72 August 4th:
"It is my understanding that removing the mech pump and pushrod and putting in a block off plate can cause an internal oil leak of sorts because there is a gallery that lubricates the pushrod."
BobD - 1978 Bus . . . . . . . . . . .111,130 miles
Chloe - 1970 bus . . . . . . . . . . . 206,787 miles
Naranja - 1977 Westfalia . . . . . 94,615 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 72,990 miles

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hambone
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Post by hambone » Thu Aug 12, 2010 7:57 am

:geek:
You could still remove the pushrod though.
http://greencascadia.blogspot.com
http://pdxvolksfolks.blogspot.com
it balances on your head just like a mattress balances on a bottle of wine
your brand new leopard skin pillbox hat

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RSorak 71Westy
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Post by RSorak 71Westy » Thu Aug 12, 2010 8:18 am

You could but you wouldn't want to, because the internal oil leak Colin refers to above is NOT a good thing..
Take care,
Rick
Stock 1600 w/dual Solex 34's and header. mildly ported heads and EMPI elephant's feet. SVDA W/pertronix. 73 Thing has been sold. BTW I am a pro wrench have been fixing cars for living for over 30 yrs.

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Oregon72
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Post by Oregon72 » Thu Aug 12, 2010 9:28 am

Amskeptic wrote:
If I am reading this correctly, taking the signal from the coil defeats the entire purpose of a relay.
Hal and I talked about this at the lab. Hal said this would be safe because it was a 5 prong relay. This came out of a vw rabbit. Hal correct me if I'm wrong. The relay is hooked up to both #15 on the coil as well as #1 (green points wire).

This is what I have currently

Image


Edit ----- Just found this thread on the Samba http://www.thesamba.com/vw/forum/viewto ... pump+relay

Here is the difference and the point Hal was trying to make to me after I had a pint of Superdog IPA --- 31b on the relay to #1 terminal on the coil is the thing that makes this relay safe. When the coil stops firing, the fuel pump stops. Let me know if my bus is still a rolling inferno of hell-fire waiting to happen at the bottom of some gully in the Clacky.
-'72 Westy-

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