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Fuel Pump Removal problem...

Discussion in '365 GT4 2+2/400/412' started by 57Wayne, Apr 17, 2021.

  1. 57Wayne

    57Wayne Karting

    Mar 29, 2015
    120
    Wilbraham MA
    Full Name:
    Wayne Thresher
    #1 57Wayne, Apr 17, 2021
    Last edited: Apr 17, 2021
    Well, being spring time, it is the start of the new repair season...after being put away last fall all ready to go, one fuel pump has finally died over the winter slumber. Confirmed dead; connector off at the connector under the boot in the engine bay, power at the connectors at the pumps, right side not running, left side running. So I bought both pumps and new filters. Got into it today, lines off, retaining rings off and it feels like whoever was in there last might have used silicone on the seal rings, The pump assembly housings are stuck firmly in place. I've put some acetone around the flange area hoping it will seep in and dissolve the silicone. I tried prying around the edges and can see a little movement of the black (plastic?) top of the assembly. hoping the acetone does not damage that material if it is a plastic.
    Has anyone run into this and successfully resolved it before?
    While I am at it, the lines connecting to the fuel pump assy are all the tan colored lines; seem to be in OK shape, but pre-ethanol. These are shrink fit on the plastic elbows at the tanks and have fittings to attach to hard lines after they exit the trunk area. What is the recommended replacement for these? Standard 3/8" hose and hose clamps? And what looks like 1.25" hose, 5" on each side, coupling the fuel tanks. I assume there is a fuel hose this size available; has someone done this recently and can advise where to get it? (I have not checked anywhere, just thought of it while I was typing.)
    Thanks.
     
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  3. raemin

    raemin Formula 3

    Jan 16, 2007
    1,218
    Lyon (FR)
    Full Name:
    R. Emin
    I've replaced most of my lines with Cohline(UK) products. You can drop them an e-mail if need be they are very helpful, do accept small quantities orders, are willing to order from the fctory if need be and do offer reasonable shipping. I cannot give first hand experience on these fuel lines, as when I was about to order these last lines, Brexit was a huge mess, so had to source an alternative locally.

    The fuel lines are not as hard to substitute as other lines, these are the ones I bought : https://www.oc-pro.fr/durite-carburant-de-14-x-22-c2x19017768 . The specifications of the Cohline are better though.
     
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  4. 57Wayne

    57Wayne Karting

    Mar 29, 2015
    120
    Wilbraham MA
    Full Name:
    Wayne Thresher
    Of course the acetone was all evaporated by today..turned out they were both just good and stuck, no RTV. I used a paint can opening tool to get at and just under the edge. After the first spot popped free, the rest followed!
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  5. 57Wayne

    57Wayne Karting

    Mar 29, 2015
    120
    Wilbraham MA
    Full Name:
    Wayne Thresher
    Next the rubber collar around the pump was a gummy mess and lots of black used to be rubber pieces were in the tank filter and in the tank. If you didn't know, the filter basket pops out of the plastic housing.
    If the pump strap clips are broken on the plastic housing it will be impossible to geth
     
  6. 57Wayne

    57Wayne Karting

    Mar 29, 2015
    120
    Wilbraham MA
    Full Name:
    Wayne Thresher
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  8. raemin

    raemin Formula 3

    Jan 16, 2007
    1,218
    Lyon (FR)
    Full Name:
    R. Emin
    Which car do you have? Pictures of the pump also would help as there are some significant differences between early carbed cars, 400i and 412.
     
  9. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    22,191
    Texas
    Full Name:
    Steve Magnusson
  10. raemin

    raemin Formula 3

    Jan 16, 2007
    1,218
    Lyon (FR)
    Full Name:
    R. Emin
    This complexity adds another possible hot start problem: one would not notice when the hoses inside the tanks get leaky and cannot retain pressure any-more. Did not experience it myself, but my cousin scratched his head for an entire week before he could track this loss of pressure. On the positive side, the trunk of the 412 smells much better as most of the fuel leaks do remain within the tank...
     
  11. 57Wayne

    57Wayne Karting

    Mar 29, 2015
    120
    Wilbraham MA
    Full Name:
    Wayne Thresher
    Sorry for the gap in responses. My phone does strange things when I try using the app on it. Thank you for the replies. I ended up getting the pump "gaskets" and vibration isolators from Ricambi in North Carolina. Bought the fuel filters from eEuroparts and pumps from Rock Auto. Also bought the seal rings for the tank interface and a second set of isolators in parallel from Ferrari Parts Exchange. I had ordered parts and not heard anything from them so bought a set from Ricambi. Received the parts from North Carolina and then got word my parts were coming from FPE. Viton o-rings came from a Harbor Freight kit. A110 size. The lines inside the tank in the pump assembly are some kind of plastic that was still flexible and in good shape. Lines from the tank are the same material with a rubbery coating. They are shrink fit to the fittings and again were in good shape so I reused them. Drained the tanks using an in-line fuel pump hooked to a switch and enough fuel line to neatly pump fuel into my empty gas cans.
    Came up with a pretty simple repair for my cracked tabs on the fuel chamber. Interestingly, a 348 uses the same chamber but does not use the retainer tabs. (slots). Had to file a little extra clearance in the tank opening to clear; maybe .020". Put a rag in the tank and let the aluminum chips fall into it, then collected it out and wiped it down with the little remains of the gas in the tank.
    Drained the fuel out of the crossover and changed the filters underneath the car. All back together; put in 5 gallons of fuel...still running on six cyl. Disconnected pump power and ran the car until it wouldn't run to make sure pressure was bled down. Went to remove the right side pump again and fuel sprayed out. Tried to run the car down again and no difference. No fuel to the injectors (plugs are dry) and holding pressure. Waiting for an M12 banjo fitting to be able to connect a line to the CIS distributor outlet to check flow. I am thinking the filter at the outlet of the CIS distributor is blocked. That would keep the diaphragm deflected upward and prevent flow to the injectors. Should have the parts tomorrow to test.
    Photo is my left side pump assy with repaired fuel chamber tabs.
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  13. raemin

    raemin Formula 3

    Jan 16, 2007
    1,218
    Lyon (FR)
    Full Name:
    R. Emin
    #10 raemin, May 6, 2021
    Last edited: May 6, 2021
    have you tried to disconnect the fuel distributor return line? If some fuel (more or less 10 litres / minutes from memory) is not coming back to the tank, then you can disconnect the distributor input and check if the fuel is coming from the pumps.

    If the fuel gets in but does not get out then , you will have to check the k-jet. If it does not get in then focus on the pumps.
     
  14. 57Wayne

    57Wayne Karting

    Mar 29, 2015
    120
    Wilbraham MA
    Full Name:
    Wayne Thresher
    Thanks @raemin . I received my banjo fittings to run the fuel test today and ran it tonight. I knew my theory on the check valve was wrong when I got back out to the garage because the filter is on the inlet...in the fitting between the line and CIS distributor.
    No flow at the outlet...disconnected the inlet and plumbed it up...nothing from the hose but had fuel coming out the inlet port on the CIS distributor. Just a small amount, but apparently the source of the pressure in the line that made me think the pump was running until it couldn't.. The crossover looks like it is between the two WURs and the small diameter line crosses the front of the engine.
    Disconnected the power to the left side pump and the trickle flow stopped. Still nothing from the right side pump.
    Disconnected both and hooked a separate battery and power supply to the right side pump. Switched on and got ~1300 ml of fuel in 30 sec. Hmmm... back to the car wiring...I measure 12.2 volts at the connectors, hook up the pump to the car wiring and nothing...So I hooked up one of the old pumps that does still work. Nothing...terminals were exposed so I checked...0 volts essentially. Disconnected the ground and measured again...12.2 volts.
    SO...I am getting voltage but not current. Thought I had resolved all that with the new relay board and all new relays, new connectors to replace any heat damaged. Soldered any crimps I was not happy with.
    Guess I have to scratch my head and think about it some more...back at it tomorrow night. Might need some thinking fluid.
     
  15. raemin

    raemin Formula 3

    Jan 16, 2007
    1,218
    Lyon (FR)
    Full Name:
    R. Emin
    Just saw my horrendous typo: that's obviously not 10l / min. 850cc / 30 seconds is what you should have... That's for the return line. 1300cc out of the input line does not seem seem totally off, but I would check the return line for 850cc in order to validate for sure that the pump properly works.

    As far as your electrical gremlins are concerned, may be:
    1. try fist to apply 12V on the cable directly after the relay board
    2. if 1) works remove the pump relay and apply 12v the the post that is normally fed by relay pin 87
    3. if 1) & 2) work use silver grease wherever you can (fuse tabs, relay tabs, connectors pins) & Swap left/right relays
    4. if 1) fails, remove passenger seat and carpets and trace the big cables under the cigarette lighters that are heading toward the door pillar. Pay attention to the cables that are under the rear passenger feet.
    5. if 4) works remove the central console and trace the cable further... Next to the gearbox shifter, there are quite a few fastin-faston , connectors that do allow to "split" the harness, I do not remember if the fuel pump harness is passing through one of these, but give it a look.

    That's where the cables for the pumps are located:
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    the pump cables are the one in the black sleeve (the coloured ones are specific to my car audio).
     
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  16. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    22,191
    Texas
    Full Name:
    Steve Magnusson
    This indicates that you have a bad connection somewhere. It's not a completely open bad connection (infinite Ohms), but more like 100s~1000s Ohms. Along the lines of raemin's comments, remove each fuel pump relay, and measure the resistance from the metal female terminal 87 of the relay socket to the disconnected +12V wire at each fuel pump. Should be something like just a few Ohms maximum or even less. This will help you decide whether the unwanted high resistance is: 1) in the path from the relay terminal 87 to the fuel pump, or 2) in the path from the +12V terminal of the battery to terminal 30 of the fuel pump relay socket.
     
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  17. 57Wayne

    57Wayne Karting

    Mar 29, 2015
    120
    Wilbraham MA
    Full Name:
    Wayne Thresher
    Found it...started with a resistance of 322 MegOhms... pretty bad. Disassembled the interior looking for the errant junction. Never found the wires to the pump under the console; they actually run through the RH rocker panel and up over the RH rear wheel housing, through a grommet into the trunk. This would have been a 30 minute job if I knew where the connector shown on the schematic is located! There is only one connector shown between the relay board connection and the fuel pump. It is located directly behind the battery. Since the battery was already disconnected, all I had to do was remove the one retainer bolt and remove the battery! Next person doing this job will hopefully find this. Photos below. It was obvious as soon as I found it, which pin was at issue. The plastic of the connector housing was discolored from heat as the connector on the relay board had been when I replaced it. Should have dealt with this back then, but I did not know it was there!
    So, when you replace your relay board and see evidence the fuel pump circuits had experienced high current / heat MAKE SURE YOU CHECK THIS CONNECTOR AS WELL!
    I don't have it back together yet; scratched the connector contacts with a tiny screwdriver and applied stabilant 22. Measures 0.05 ohms. from the relay terminal 87 to the fuel pump connector now. Pretty sure that's going to work. The other side is about 1.3 ohms.
    Since I have it all apart, I figure I should address my failed neutral safety switch (starting control switch). I have it jumped at the relay to ignore it. Also I can correct a swapped wire issue I had from last time. Another positive of pulling the interior apart is that I found all of my missing combs! The biggest pain in removing things was the air vent above the gages to access the two upper console bolts. It's been damaged by a prior removal effort.
    Has anyone found an alternate to the $100+ Neutral safety switch?
    Thanks @Steve Magnusson and @raemin for your thoughts.
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  18. raemin

    raemin Formula 3

    Jan 16, 2007
    1,218
    Lyon (FR)
    Full Name:
    R. Emin
    Congratulation on solving this issue. The new relay board and the harness relocation was a move in the wrong direction on these cars.

    Judging by your pictures, they downsized to connectors. The stock 6.3mm spade connectors already had a hard time coping with the fuel pump current no wonder why these 4.8mm connectors are burning.

    The location is also a big issue. This is how my windscreen wipers connector ended. It is roughly in the same location as your failed fuel pump connectors.

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  19. 57Wayne

    57Wayne Karting

    Mar 29, 2015
    120
    Wilbraham MA
    Full Name:
    Wayne Thresher
    That's a pretty scary looking connector! Checked mine; tucked behind the wiper motor, and it looks fine. The wipers work kind of slowly so deserve a little more checking.
    Still contemplating splitting the fuel pump wires from the connector and running them through a separate heavier duty connector.
     

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