Ridemalibu Motorcycle Rentals & Tours – Los Angeles CA
  1. Ciao Guest - You’ve landed at the ultimate Guzzi site. In SoCal? See the SERVICE tab above for the best in service, tires, tuning and installation of our products or custom work. NEW FORUM REGISTRATIONS REQUIRE EMAIL ACTIVATION - CHECK YOUR SPAM FOLDER. ALWAYS TRY A SEARCH BEFORE STARTING A NEW TOPIC - Most questions you may have are already answered on the Forum with FACTS, NOT OPINIONS. PLEASE DON'T BE A DRIVE-BY POSTER: As a common courtesy, check back if you are posting elsewhere on the web. Note there's decades of Guzzi hands-on experienced help on this site, all whom give endless amounts of their time for free; BE COURTEOUS AND RESPECTFUL! There is zero tolerance on personal attacks and off-site links to other Forums or competing products. Also be sure to click on the STORE link also above for our 600+ product inventory, including many of our 100% Made-in-house-USA GTM products and engine kits. We appreciate the consideration, understanding and your business... past and future. And if you haven't seen our MotoCycle (not) art, click on the BUILDS tab above to see our work at our sister business; GT MotoCycles®-- WE ARE ONLINE ONLY - NO PHONE CALLS MADE OR RECEIVED.

Quota 1000 Fuel Pump

Discussion in 'Quota & TT' started by DavidN, May 14, 2019.

  1. DavidN

    DavidN Just got it firing!

    Joined:
    May 14, 2019
    Messages:
    7
    Likes Received:
    0
    Location:
    Portugal
    Hey there!

    New to the forum and new to the guzzi world.

    Got myself a '91 Quota 1000. I bought it knowing that it had some running issues but I decided to bite the bullet anyway. This bike is to good looking and rare to be ignored.
    First of all, is it normal for the fuel pump to run continuously? I guess it would stop once it got to a certain pressure.
    I´ve balanced the throttle body and check the TPS... everything seems nice. However after riding a bit I have a very hard time to restart the engine. I will crank and crank but just won't fire up. If I let it cool down it will start again pretty easily.

    Any thoughts on this guys?

    Cheers from Portugal.
     
  2. john zibell

    john zibell Moderator Staff Member GT di Razza Pura

    Joined:
    Oct 28, 2008
    Messages:
    8,016
    Likes Received:
    852
    Location:
    Huntsville, AL
    When you turn the key on, it should only run for a few seconds and stop. Once stops then try to start. Considering the age of the fuel pump, it may need replacement.
     
  3. DavidN

    DavidN Just got it firing!

    Joined:
    May 14, 2019
    Messages:
    7
    Likes Received:
    0
    Location:
    Portugal
    Thanks for your reply. I thought so as well. But since this is a very rudimentary EFI system I had my doubts.
     
  4. john zibell

    john zibell Moderator Staff Member GT di Razza Pura

    Joined:
    Oct 28, 2008
    Messages:
    8,016
    Likes Received:
    852
    Location:
    Huntsville, AL
    Duration of the fuel pump running is controlled by the ECU. There may be an issue with the programming. Or the fuel pump relay may be stuck closed making it run continuously. Let's hope it is the relay.
     
  5. DavidN

    DavidN Just got it firing!

    Joined:
    May 14, 2019
    Messages:
    7
    Likes Received:
    0
    Location:
    Portugal
    Thanks John. I'll check the relay. I wonder if the fuel pressure sensor is built in the pump or if it's external...
     
  6. V700Steve

    V700Steve High Miler GT di Razza Pura

    Joined:
    Dec 8, 2008
    Messages:
    919
    Likes Received:
    327
    Location:
    Atlanta area, GA
    There is no pressure sensor, it is timed by the ecu. There is a pressure regulator in the system to keep fuel at a steady 3bar in hoses to injectors. It is mechanical not electronic. It is in line on the 1000cc and on the return tap to tank on the 1100cc.
     
    Last edited: May 16, 2019
  7. DavidN

    DavidN Just got it firing!

    Joined:
    May 14, 2019
    Messages:
    7
    Likes Received:
    0
    Location:
    Portugal
    Thanks Steve. I'm aware of that regulator. If memory serves me right, it has one fuel inlet supplied from the filter, one vacuum connection to the intake manifold, one outlet to the injectors and one outlet bypass to the tank.
    But I'm missing something. If it is only timed, how can the that pressure (3bar) be maintained? I guess there would be a pressure drop sooner or later... Hummm

    BTW... since my pump works continuously, there is a constant stream of fuel flowing back into the tank. This obviously can't be right.


    Thanks for the feedback guys!
     
  8. john zibell

    john zibell Moderator Staff Member GT di Razza Pura

    Joined:
    Oct 28, 2008
    Messages:
    8,016
    Likes Received:
    852
    Location:
    Huntsville, AL
    David,

    The ECU runs the fuel pump for a few seconds to pressurize the system then shuts off. On a correctly functioning bike that is your indicator to start the engine. Once the engine is running, the ECU keeps the fuel pump running. Besides it being a stuck relay, someone may have bypassed that relay in the past to keep the pump running.
     
    V700Steve likes this.
  9. DavidN

    DavidN Just got it firing!

    Joined:
    May 14, 2019
    Messages:
    7
    Likes Received:
    0
    Location:
    Portugal
    OK. That finally makes sense to me. Wouldn't be surprised if it had been bypassed... The bike has clear signs of being mistreated.
    I'll keep you guys posted.
    Cheers! Have a good one!
     
  10. DavidN

    DavidN Just got it firing!

    Joined:
    May 14, 2019
    Messages:
    7
    Likes Received:
    0
    Location:
    Portugal
    Hi!

    So yesterday I finally had some time to get my hands on the Quota.
    The relays seem to be working properly. Even interchanged the injection solenoid with the pump solenoid and nothing changed. I traced the pump wiring back to the ECU and everything seemed ok. The pump, on the other hand, seems to have been replaced. So, long story short, the pump runs continuously as soon as I flip the switch to RUN. So I guess it might be ECU related, as John Zibell pointed out.
    But my pursuit for Gremlins didn't stop there. The horns work, but somehow someone bypassed the horn relay. I didn't think much of this so I plowed ahead.
    I tested the engine head temperature NTC. It was ok.
    Then I spotted the air sensor mounted underneath the left horn. It was clearly damaged... half of it was missing. How much can a non existing air temperature sensor affect the poor performance and the hard start when hot??
    It's exactly the same model as the engine temperature sensor, so I'm going to order one right after I post this.

    Cheers!
     
  11. john zibell

    john zibell Moderator Staff Member GT di Razza Pura

    Joined:
    Oct 28, 2008
    Messages:
    8,016
    Likes Received:
    852
    Location:
    Huntsville, AL
    A damaged air temperature sensor will impact starting and running. It is part of the calculation for air density. It seems engine temperature has more effect on running, but the air temperature part of the equation is needed as well.
     
  12. DavidN

    DavidN Just got it firing!

    Joined:
    May 14, 2019
    Messages:
    7
    Likes Received:
    0
    Location:
    Portugal
    So I finally replaced the air temperature sensor but the symptoms didn't change. I checked the valves and the intake had no clearance whatsoever. Tuned them but unfortunately the bike is still very difficult to restart when hot and stalls at full throttle. On a cold start the quota revs up nicely but as the engine starts to get warmer she will act up on me.
    Considering going to a Guzzi dealer to see what they have to say.
     
  13. john zibell

    john zibell Moderator Staff Member GT di Razza Pura

    Joined:
    Oct 28, 2008
    Messages:
    8,016
    Likes Received:
    852
    Location:
    Huntsville, AL
    Next possibility is the engine temperature sensor. Have you checked that yet? That sensor has more impact on a hot engine on controlling injector timing.
     
  14. johnno

    johnno Cruisin' Guzzisti GT Contributor

    Joined:
    Nov 6, 2008
    Messages:
    151
    Likes Received:
    14
    I have tested a few ECU on my 1100 sport I and it was always a faulty ECU once relay as been checked .
     
  15. Moto-Uno

    Moto-Uno Cruisin' Guzzisti

    Joined:
    Aug 7, 2016
    Messages:
    124
    Likes Received:
    25
    Location:
    B.C
    I s there a remote possibility that you may have a coil problem when it heats up ? Have a spare plug handy
    and remove the ground electrode ( it simulates the spark energy required under compression) and simply
    remove a plug lead , install test plug and crank engine to test for spark (test plug grounded of course ) Peter
     

Share This Page