Parts Catalog Accessories Catalog Tech Info Tech Forums
 
  Search our site:    
 Cart  | Project List | Order Status | Help    
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Dec 2004
Location: Westcoast Canada
Posts: 16
Electric Fuel Pump

It has been some 2 years since I started this project (probably over my head) but I worked on it off and on during this time. I finally put the rebuilt engine back in the old car, and hooked everything back together. Turned the key with my wife watching for leaks (or small fires), it started but died very quickly maybe 30 seconds. It seemed to be starving for fuel. After hours of checking past posts, everything from cleaning the screen in the tank to checking fuel lines, the fuel pump hums but doesn't pump gas out of it. Before I buy a new expensive fuel pump, a question. Is there anything I might have missed? There is fuel coming out of the line from the tank by gravity. The thing that I wonder is, could some old sediments of gas or rust plugged it up. I read that you can't rebuild these pumps but can you clean them up if debris went inside?
Thanks Wade
__________________
'72 911 T
Old 08-26-2007, 02:42 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #1 (permalink)
Registered User
 
Walt Fricke's Avatar
 
Join Date: May 2004
Location: Boulder, Colorado
Posts: 3,567
Wade

Bummer. Good idea having someone doing leak/fire watch. Starting up a rebuild is always a bit tense.

30 seconds sounds suspiciously like one float bowl's worth of running time. If the pump is bad, how did these get filled to start with?

What do these Ts run? Zeniths? And a low pressure fuel pump? Anyway, don't Zeniths have a float system, and a float level? Can you check that? If the float bowl in the carb is full, your fuel pump is most likely working.

If you can't check that, can you disconnect the fuel line at the carbs? See if the fuel pump will pump out from there. If yes, probably not a pump/obstructed line issue.

If no, disconnect the carb side line from the pump and (carefully - best would be to attach another length of hose so you can direct it into a can or bottle) see if it pumps out there. If yes, perhaps there is a problem with the long run of the fuel line.

If no, and you say you have fuel coming out by gravity at the fuel pump inlet, then there is probably a pump problem. I'd remove it and see if I could fill it with carb cleaner from the outlet side, then blow air through from that side to backflush it. If it has a screen, it will be on the inlet side. Then rig up the pump on your workbench to see if it will draw when fed 12V. If it won't, sounds like time to get another pump.

Just my approach based on what you have said. I'm trusting that you checked out the ignition side, and the distributor didn't get loose, or the points break, or the CD box (if it has one) or coil just happened coincidentally to fail - i.e., you have a nice fat spark at about the right time.

Walt Fricke
Old 08-26-2007, 09:52 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #2 (permalink)
Registered User
 
Join Date: Dec 2004
Location: Westcoast Canada
Posts: 16
Thanks Walt,
This engine is a MFI system. I did disconnect the electric pump and attached a hose from the supply inlet to a container with fuel, then connected a the pump to a battery but no fuel pumped out the outlet that would be connected to the fuel filter. I will try your idea of injecting carb cleaner to the pump and will let you know the result.

Thanks Wade
__________________
'72 911 T
Old 08-27-2007, 11:54 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #3 (permalink)
Registered User
 
Join Date: Feb 2007
Location: new zealand
Posts: 28
strip the pump if its a roller pump the rollers can get gummed up with the residue from old gas this happened to mine after five years in storage use spray pain thinner to remove residue rebuild and test if the rollers are not free they dont fly out and pump properly (they can sit glued into the impeller)
Old 08-30-2007, 12:55 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #4 (permalink)
Registered User
 
Join Date: Dec 2004
Location: Westcoast Canada
Posts: 16
Thanks Walt & jsbc,
I took it apart, and noticed that the valve by the return tube was a little sticky. I removed the crimped fitting on the side of the pump and cleaned up the spring assembly inside. I then put it back together, pumped some carb cleaner through and seemed to work fine. I hooked it up to the carís fuel lines, and turned the ignition and the car fired up. Thanks again, Wade.
__________________
'72 911 T
Old 08-30-2007, 07:36 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #5 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 07:34 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 


DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.