News

to rifledriver (poor running 1990 tr)

Discussion in 'Technical Q&A' started by mjcdc, Sep 1, 2004.

  1. mjcdc

    mjcdc Rookie

    Jun 8, 2004
    5
    colfax california
    Full Name:
    mark
    couldn't send to you, so posted. took your advice, used timing light and have all 12 cyls firing, have 65lbs of pressure before fuel filter and just replaced filter, removed airbox and i call them air plungers? depressed good side and the engine stumbles and once to die, the bad side has no change when you depress it.

    thank you, look forward to hearing back.

    mark
     
  2. To remove this ad click here.

  3. Rifledriver

    Rifledriver Two Time F1 World Champ

    Apr 29, 2004
    26,951
    Austin TX
    Full Name:
    Brian Crall
    I think your timing light test has pretty well eliminated an ignition problem, and depressing the air flow plate has located the bank that is not firing. But you still don't know about compression. Just to eliminate it as a problem I think you should perform a compression test. Pull all twelve plugs, remove the multi plug located on the top of each ignition coil and check compression. If all twelve are reasonably close you can eliminate that and concentrate on the fuel sys. Also when you depressed the air flow plates did they offer about equal resistance? And when you pull the plugs pay attention to their appearance, you are looking for consistancy from bank to bank. Are one side dry and clean and the others wet, black, or otherwise?
     
  4. ferrarifixer

    ferrarifixer F1 Veteran
    BANNED

    Jul 22, 2003
    8,520
    Melbourne
    Full Name:
    Phil Hughes
    If pressing down your fuel metering plate has no resistance/makes no difference on the one side, then you most likely have lost fuel pressure to that bank. Check your pressures/filters for both banks? (Your post just said filter, not 's)

    A compression problem would not remove the fuel pressure from it.

    If you have lost pressure, go to the fuse/relay board and bridge terminals 30/87 of each pump relay with engine off but ign on. Each pump will run in turn. if not, check the big white plastic connectors on the fuse board for brown stains from burning etc. Of course, check fuses too.
     
  5. Rifledriver

    Rifledriver Two Time F1 World Champ

    Apr 29, 2004
    26,951
    Austin TX
    Full Name:
    Brian Crall
    We don't know if the plate has no resistance yet. And it's obvious that compression has nothing to do with that. I'm just trying to get him to do some methodical diagnostic work to eliminate other potentials before diving head first into the fuel system. You and I have a great deal more experience and equipment at our disposal to narrow it down quickly than he. But to prevent him from on going on non productive goose chases, I think it wise to be certain it's fuel related before performing fuel related tests.
     
  6. mjcdc

    mjcdc Rookie

    Jun 8, 2004
    5
    colfax california
    Full Name:
    mark
    depressing the plate makes no diff in it's running on the bad bank, and felt softer. did confirm 12 volts to pump, and have replaced pump,(that was the first thought) and switched electrical connections down at the pumps, talked to buddy who was holding pressure gauge, he said it shot to 65psi and then started spraying so we shut it down, our connection was not exact science!

    my buddy heard from someone that the system is pretty fullproof, the vehicle has about 17k miles, and that typically it is an electrical connection (simple) failure, any comments or ideas, the car did spend sometime in Japan prior to my ownership.

    thank you,

    mark
     
  7. To remove this ad click here.

  8. Rifledriver

    Rifledriver Two Time F1 World Champ

    Apr 29, 2004
    26,951
    Austin TX
    Full Name:
    Brian Crall
    65 lbs. is low for that sys but if you had a great big leak I'm not surprised you got a low reading. And yes the sys is pretty foolproof (except for a variety of reasons that keep the pump from running) and the Bosch KE sys that was peculiar to US Testarossa's has a rather involved diagnostic scheme. All the more reason I still want you to do a compression check and to give a report on the spark plugs. There are really no shortcuts if you want to find a problem efficiently. You are dealing with a car that has a significant running problem, we are reasonably certain that it has ignition, it has a running fuel pump, and we all agree that those fuel systems except for the pumps are very reliable. The one question that really needs to be answered to go any farther, we haven't even asked yet, COMPRESSION. And besides having a good look at the spark plugs (all of them) could possibly tell us a lot. Then and only then if we decide it is a fuel sys problem I will be happy to fax or mail you a copy of the factory diagnostic procedures (several pages), the bulk of which you can perform with a good VOM, a few jumper leads and a friend to help.
    A competant professional mechanic doesn't ignore any of these things, in an unknown situation you always have to go to basics. We just have equipment at our disposal to test, comfirm, or eliminate many things in a hurry so that we can focus on a specific area to find a resolution. So get to it, once we know where to look fixing it will be in sight.
     

Share This Page