Fuel pump regulator

If I ever need some extra work, I reckon that circuit could be done in about 20 minutes on a decent CAD package.

 

Looking at my Bus wiring diagrams, any reason why 15 shouldn't come off the positive on the coil? It seems a convenient place to pick it off....but something in my head is saying bet it's noisy as hell there, as a supply....

 

Yep, take it off the coil +ve.

 

Ah, ok bit more study, looks like there's a switched ignition supply to the rear light clusters, or I might be able to steal one off the T socket.

My struggle is I don't have a diagram for my Bus, I got a 1700 and USA model diagrams, mine is a cross between the two.

 

Take. It. Off. The. Coil.

 

Found a 15 driving my split charge relay

 

Just take it off the coil!

 

Non! Actually it's perfect as I think I can mount the relay next to the T connector

 

Well spent more time figuring out where to eventually mount it and then how to 'bench' test it, but..........wait for it....





Success


I had to work out how to test it with no one to help me and no fuel in the Bus. The red and yellow clip leads are going to my trusty Fluke in continuity mode, which is sitting on the R&R bed. Turn the engine over and I get a satisfying audible beep that I can hear from the driver's seat

 

The coil back EMF hits about 100 volts.
With a 123 there is no back EMF, just a 12 volt tall switching signal.

 

Would one of these relays work with a T25 electronic ignition setup?

Seems a better option than just using ignition feed for the fuel pump as ours is currently.

 

Yes

 

+1

Regret to say, the place where I got mine has unfortunately sold out

 

Looks like I'll have to get one ordered then! Thanks both, another job to add to the list!

 

Last one with integral fuse, German made by Herth & Buss. https://www.ebay.co.uk/itm/New-Fuel-Pump-Relay-with-fuse-for-Audi-80-Mk1-Golf-Jetta-K-Jetronic-engines/172740434564?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=20160908105057&meid=3426bc71602c47bc978e05c0e66b44da&pid=100675&rk=5&rkt=15&mehot=ag&sd=323298227155&itm=172740434564&pmt=0&noa=1&pg=2380057&_trksid=p2380057.c100675.m4236&_trkparms=pageci:155a51f6-7aed-11ea-b04b-4e422690e81a|parentrq:6295f5d61710ad397eef37f0ffed47bb|iid:1

 

Or this one without a fuse. https://www.ebay.co.uk/itm/AUDI-80-...a=1&pg=2334524&_trksid=p2334524.c100667.m2042

 

Resurrecting an old thread while watching Car Sos and remembering the time my Sierra suddenly cut out leaving an uneven campsite, has anyone considered or fitted one of the cut off valves that used to stop the fuel pump in the case of an accident ... or isn't it appropriate for our purposes?

 

Yep.. fitted in line with fuel pump same live feed to open ( and close )

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Did you get a specific new one or raid a breakers yard ?