No sound from Fuel Pump | FerrariChat

No sound from Fuel Pump

Discussion in '308/328' started by GeoMetry, May 26, 2008.

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  1. GeoMetry

    GeoMetry Formula Junior

    Apr 14, 2008
    471
    Virginia
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    Richard
    #1 GeoMetry, May 26, 2008
    Car has been sitting in the garage for two days. I got in today turned the key to the run position where I always hear the fuel pump and all I heard was silence. I was pretty sure that it wouldn’t start but I tried it anyway and nothing.

    I checked the fuse it looks ok.

    So back into the house and fire up FerrariChat (At least that works)

    I searched quite a bit and found a few things that I am not sure apply to my car.

    Does an 85 308 QV have a fuel pump strap switch under the driver’s seat???

    There was a long discussion about the [post=136964772] safety switch [/post] I’m not sure if it applies to my problem.

    Until today my fuel pump ran constantly when the ignition switch was in the run position but there was a thread discussing whether or not that was normal.

    I guess I am looking for the step by step trouble shooting process.

    Is there a safe way to check the fuel pump? Can I just apply 12v to it directly?
     
  2. Hans

    Hans F1 Veteran

    Feb 17, 2006
    7,734
    Hilversum, Netherlands
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    Hans Teijgeler
    #2 Hans, May 26, 2008
    Yup, you can apply 12 volt to it. Bear in mind that without fuse, you run it unprotected. But since your fuses checked out okay, this will most likely be no issue.

    You could also turn the thing around: Check if you've got 12 volt AT THE PUMP. Just use a light bulb if you don't have a multimeter available.

    These pumps DO fail, and tend to do it rather suddenly. I've replaced mine just a couple of weeks ago. Drove 100 miles with the car and had the engine die on me 15 feet from my garage.

    Hans
     
  3. desire308

    desire308 Formula 3

    Oct 19, 2007
    1,433
    Florida
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    Peter W
    #3 desire308, May 26, 2008
    I think the safety switch can be disconnected at the fuel distributer. Its a harness connection on the side. Un plug it and turn the igntion to the first position. You should hear the pump running. Also check your pump relay. It could be dead.
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,146
    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
    #4 Steve Magnusson, May 26, 2008
    This is definitely not stock (and somewhat unsafe) for an '85 308QV and would indicate that modifications have been made to your car.

    No, the "safety switch" (and a couple of relays) is (are) what the V8 K-Jet F use to give the desired result of:

    engine not running + key "on" = fuel pump does not run
    engine running (drawing in air and opening the contacts in the safety switch) + key "on" = fuel pump runs
    starter motor cranking = fuel pump runs (whether or not the safety switch contacts are open or closed)

    As Hans said, it's just a simple +12V motor so no problem to apply +12V via another source to see if it runs, but you should really try to figure out what modifications were made, why they were made, and why you shouldn't put it back to stock IMO. Unlike the tape switches in the seat bottom of the carbed cars, that everyone rightly does remove because they are just too unreliable (and the fuel pressure isn't nutty high), your stock 308QV safety system works fairly well, and most other K-Jet F model Owners aren't making any modifications.

    Another area to check is the condition of the fuseblock itself (not just the fuse). Unless your modification involved adding a new +12V power wire from some other source, you may still be getting the large current from the fuseblock which can melt/degrade the riveted connections.

    Have you examined the safety switch? Do you have one? Is it plugged in?
     
  5. GeoMetry

    GeoMetry Formula Junior

    Apr 14, 2008
    471
    Virginia
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    Richard
    #5 GeoMetry, May 26, 2008
    No voltage at the pump. I am beginning to suspect that there have been some electrical system modifications. Clues... Wires hanging out from under the dashboard that don't go anywhere. Snipped off wires in a few places. The dealer said they noticed some "after market wiring" And now this fuel pump problem and the statement Steve Magnusson made about the proper functioning of the safety switch and the fuel pump. I'll post some pictures soon. I may as well order my Fuse blocks from Birdman today.
     
  6. GeoMetry

    GeoMetry Formula Junior

    Apr 14, 2008
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    #6 GeoMetry, May 26, 2008
    Last edited by a moderator: Sep 7, 2017
    I have pointed out several things that look odd to me in this picture

    1 Wire changes from yellow to blue (then back to yellow not shown)
    2 Says it is an antenna noise isolator
    3 In line fuse. connected to the sixth terminal on the fuse block
    4 another in line fuse
    5 Wire to nothing
    6 Some sort of FM signal booster

    Are the markings on the relays normal? Do you see anything else odd?
    Image Unavailable, Please Login
     
  7. GeoMetry

    GeoMetry Formula Junior

    Apr 14, 2008
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    Richard
    #7 GeoMetry, May 26, 2008
    Last edited by a moderator: Sep 7, 2017
    Ignoring the entire power amplifier mess...

    1 Once again the wire to nothing
    2 I think this used to be the lead from the antenna
    3 Why would someone cut this wire?

    Do you see anything else unusual here?
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  8. GeoMetry

    GeoMetry Formula Junior

    Apr 14, 2008
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    #8 GeoMetry, May 26, 2008
    Last edited by a moderator: Sep 7, 2017
    One more loose end. And there is an inline fuse connected directly to the battery as well. Where should I start?? Oh and I almost forgot the speedometer doesn't work either.
    Image Unavailable, Please Login
     
  9. tele013

    tele013 Formula Junior

    Nov 19, 2003
    761
    Malaga, Spain
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    jesus
    #9 tele013, May 26, 2008
    Hi, i have the same problem in my 328. have i safety switch in my car ?
    Looking in the ignition key, i found no colour cables, all are red....
    have anyone outthere the cable colour codes and the correct position in the ignition key ?
    Thanks in advance
     
  10. GeoMetry

    GeoMetry Formula Junior

    Apr 14, 2008
    471
    Virginia
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    Richard
    #10 GeoMetry, May 26, 2008
    Last edited: May 26, 2008
    Here is what I have done so far to Trouble shoot my fuel pump issue.

    1 Check the fuse [PASS]
    2 Check for 12 volts at the pump [FAIL]
    3 Check for 12 volts prior to the fuse [PASS]
    4 Check for 12 volts after the fuse [FAIL]
    5 Order fuse block from Birdman.

    The fuse is good but there is no power after the fuse so I guess the fuse block is the culprit. I hope this gets me back to where I was before. Then I need to resolve the issue where the fuel pump runs constantly when the key is in the on position regardless of whether the engine is running or not. Heck I didn't even realize that was a problem until I started researching this problem. (Maybe she was trying to tell me something)
     
  11. GeoMetry

    GeoMetry Formula Junior

    Apr 14, 2008
    471
    Virginia
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    Richard
    #11 GeoMetry, May 28, 2008
    Last edited: May 28, 2008
    While waiting for the fuse blocks (to resolve the initial problem) I did some additional tests to try and solve the problem where the pump runs when the key is in the run position even if the engine is not running. I pulled the relays and tested them, they are all OK so I put them back. I tested the safety switch, it is OK. Then before reconnecting the safety switch, I bypassed the fuse (since it doesn't work), turned the key to the run position and I heard the fuel pump doing its thing. Then I turned the key back to the off position, reconnected the safety switch, turned the key to the run position and... silence. Just like it is supposed to do. I am waiting for the fuse blocks before I try to actually start the car but, I think the problem is resolved. My theory is that just the process of unplugging the safety switch and plugging it back in removed enough corrosion to make it work correctly. Probably needs some additional cleaning and maybe I should disconnect and reconnect things when ever I get a chance.

    In the second picture I posted I am still curious about the cut wire #3. What is that device under the passenger floorboard and what is the effect of cutting that wire?
     

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