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| udidwht |
 Posted: Wed Jul 14, 2010 5:42 pm Post subject: Odd fuel pump issue |
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1100cc
Joined: 23 Sep 2005
Posts: 12
Location: Ca.
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Went out and started the bus and noticed fuel leaking from the fuel pump once started. Traced it to the line from the fuel pump to the carbs. Replaced an no more leak. Or so I thought...the next day started it and the same issue again. This time fuel line/s all bone dry. Suspect fuel pump. So I undo the fitting for the filter screen on the pump to check for any FOD. Nothing found replaced fitting. Fired up the bus and no leak anywhere. Drove bus for 20 miles or so without issue. Parked the bus for the night and the next day went out and started the bus only to have the exact same issue. Again only seems to leak at start up a bit and only after setting overnight.
I've checked for fuel in the crankcase and no fuel is present. As I said earlier I checked the in pump screen for debris of any kind and screen was clean. Replaced the screen and started the bus and no leak/s in both instances. Was able to drive the bus after both instances without any fuel delivery issues. At this point I've ruled out a bad diaphragm. I'm leaning towards an intermittent blockage of some sort. Also running two fuel filters. One between fuel tank and pump and another between pump and carbs.
Bus specs:
72 Westy hardtop
96mm P/C's
42x36mm Heads
73 Web Cam w/Solids
71mm Stroke
Dual 40mm Webers (50idles, 120Mains, F11tubes, 28mmVents)
German 009 w/Pertronix
S&S 4-1 exhaust w/Quietpack
Mechanical fuel pump
Any other ideas/suggestions before I tear into her? |
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| 58 |
| Posted: Thu Jul 15, 2010 5:40 am Post subject: |
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SBS #34
Joined: 29 Jul 2004
Posts: 1250
Location: South Hill
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Have a spare pump on hand to rule out the pump? Maybe a small hole somewhere in the fuel line (Seen this a few times)
Umm, ya..
Personally I have a CB rotary pump these days so one less 'issue' so to speak.
(shrug)
_________________
Jax
'58 Single Cab,'95 GTI,'71 Panel
Well, the only way to fully describe this is: can on side, lid approximately 3 feet away, worms everywhere... -Bugly |
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| udidwht |
| Posted: Thu Jul 15, 2010 10:29 am Post subject: |
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1100cc
Joined: 23 Sep 2005
Posts: 12
Location: Ca.
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Just an update:
Went out to the bus fifteen minutes ago checked the oil. No gas in oil. Good sign. Fired up the bus and no leak/s. Not a drop. Crawled underneath and everything is bone dry. Just to add I replaced all the lines recently with the exception of the one I replaced earlier mentioned (Pump>firewall>carbs)line. That hose was approximately 2-3 years old. Old hose showed no obvious signs of damage other than being stiff. Hose was Brazilian made (braided). Replaced it with some German made hose.
At this point I'm just going to monitor it closely. In the event It needs replacing I have a rebuild kit for the pump. I know... Where did you get that? (Holy grail item) I bought it a few months back off a site in Europe. Probably the last one on the planet.
Hey 58 you running a regulator with that CB pump? Where did you wire it in. |
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| udidwht |
| Posted: Sat Jul 17, 2010 7:59 pm Post subject: |
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1100cc
Joined: 23 Sep 2005
Posts: 12
Location: Ca.
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Update:
Went a whole day no leak. The next day it leaked again. Pulled pump and found no obvious tears/holes etc. It appeared that the top diaphragm (smaller one) had rusted some on one side and lifted the guide that it slides back and forth through threw. The guide itself had come off the three pins it sits on and turned slightly sitting on top of the pins and not allowing the diaphragm to sit fully seated.
That pump has lived a long good life. I managed at least 15 yrs or so with it. |
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