fuel pump relays

Hi all,

can someone tell me when the VW fuel pump relays began having the "priming" feature where the pump would run for a few seconds after you turned the key on?

No, Dave, I haven't forgotten that you'd offered a socket, I'm *finally* getting back to that project after working my butt off for a few months at my real job.

nate

Reply to
Nate Nagel
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Forgot to mention, the reason I'm asking is I think that I want to use

321 906 059 C (with the integral fuse) but am not sure that it will prime my carb. That relay looks like it was used through '82.

nate

Reply to
Nate Nagel

I think someone did a breakdown of which fuel pump relay did what. Initial prime Hot start feature Not sure where I saw that info YEARS ago!

later model relay diagram

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>> Hi all,

Reply to
dave AKA vwdoc1

They all do that. When you turn on the ign key it gets triggered by the ign. coil (neg). It's not a priming feature it just lets the pump run for a couple of seconds. A real priming system would also inject a little fuel to get things wet...

SFC

"Nate Nagel" schreef in bericht news: snipped-for-privacy@news2.newsguy.com...

Reply to
SFC

Really? I could have sworn I'd read/heard somewhere that some earlier models did not do that. I guess "prime" is the wrong word, should read "pressurize fuel rail" or "fill carburetors" as appropriate. I def. want that feature though as when I go to start the car after it's been sitting, it takes a long time for the mech. fuel pump to refill the fuel bowls after all the fuel has evaporated out - that is my main reason for wanting to switch to an electric (that and for whatever reason I can't seem to find a mech. fuel pump that isn't loud as heck.)

The oldest WCVW I've owned was an 84, hence my question. The only socket for which I've been able to get a part number (thanks Dave!) is for an earlier car, and it looks like the later FP relays have larger/ different terminals. I doubt I would be able to find a socket for a later relay as I believe that they were integrated into the fusebox on the later cars. I do know that my '84 (and other '84, '88, and '89) all ran the pump for a few seconds after initial key on.

nate

ws2.newsguy.com...

Reply to
N8N

The reason for this electronic fp relay is not to quickly fill up the fuel lines, filter etc. but it's a safety device. In case of an accident the fp is disconnected. Why do you need a socket? You can use amp connectors that go straight on the relay.

SFC

"N8N" schreef in bericht news: snipped-for-privacy@35g2000pry.googlegroups.com... Really? I could have sworn I'd read/heard somewhere that some earlier models did not do that. I guess "prime" is the wrong word, should read "pressurize fuel rail" or "fill carburetors" as appropriate. I def. want that feature though as when I go to start the car after it's been sitting, it takes a long time for the mech. fuel pump to refill the fuel bowls after all the fuel has evaporated out - that is my main reason for wanting to switch to an electric (that and for whatever reason I can't seem to find a mech. fuel pump that isn't loud as heck.)

The oldest WCVW I've owned was an 84, hence my question. The only socket for which I've been able to get a part number (thanks Dave!) is for an earlier car, and it looks like the later FP relays have larger/ different terminals. I doubt I would be able to find a socket for a later relay as I believe that they were integrated into the fusebox on the later cars. I do know that my '84 (and other '84, '88, and '89) all ran the pump for a few seconds after initial key on.

nate

Reply to
SFC

AFAIK Yes the relay is a safety device but it is also a way to get enough power to the fuel pump(s) without overtaxing the ign switch or other circuits. Most pressurize the fuel lines in those couple of seconds after the ign switch is turned on, but I want to say that some FP relays are slightly different with their characteristics. I just can't find the information that I once saw comparing them. Unless I am totally mistaken and am thinking of something else like the Hot Start Pulse Relay.

It seems like the 83+ Rabbit had a couple of different FPRs

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description on how the FPR works
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BTW you don't have to use a VW relay and socket! ;-)

Reply to
dave AKA vwdoc1

I know that I don't *have* to, I just like the ignition-pulse safety, and the pre-run when you turn the key on. I sure could use a regular Bosch relay and/or an ice cube, but then I'd have to use an oil pressure switch and still have to put a pushbutton under the dash to bypass it to fill the fuel bowls. I know that that's not *hard,* but my concept with this car is to have an old car that I could give to my mom or girlfriend to drive without having to explain any special instructions (oh, and fast and loud.) That, and VWs are what I know :)

I wish I knew enough about electronics to determine from that schematic as to how the relay worked. I guess I could just buy a relay and test it on the bench.

If you still have that socket you sent me a pic of, drop me another email...

nate

Reply to
Nate Nagel

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