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Thread: Diagnosing loss of fuel pressure

  1. #11

    Default Re: Diagnosing loss of fuel pressure

    It would be very handy of Haltech would update to the LSU4.9 sensor type. The advantage of the CAN based Haltech one (Apart from having Yet Another Box to find a space for) is that when you use the Haltech CAN one the ECU can see the status of the sensor in the CAN messages and ignore it if it is not ready or indicating a fault.

  2. #12

    Default Re: Diagnosing loss of fuel pressure

    Installed the Radium Surge tank before I had to fly to New Zealand for work. Pump not wired in yet but the tank pump works and there are no leaks...

    Bracket for the surge tank. Where the jack used to go. I may add a brace as whilst it feels solid who knows at track speeds.
    DSCN4096 by Eipeip, on Flickr

    Bracket in place
    DSCN4097 by Eipeip, on Flickr

    Surge tank mounted
    DSCN4098 by Eipeip, on Flickr

    DSCN4099 by Eipeip, on Flickr

    in line 100 micron filter to replace the OEM. This goes to the surge tank
    DSCN4100 by Eipeip, on Flickr

    Bulkhead connectors installed
    DSCN4101 by Eipeip, on Flickr

    Hoses nipped up. Need to purchase some hose seperators and clamps to keep the hoses from rubbing on anything.
    DSCN4107 by Eipeip, on Flickr

    DSCN4108 by Eipeip, on Flickr[/quote]

  3. #13

    Default Re: Diagnosing loss of fuel pressure

    Finally the issue has been 'fixed'. Turns out fixed one problem to find another that needed to be fixed...

    Due to heat soak issues the surge tank was moved:
    DSCN4143 by Eipeip, on Flickr

    The surge tank fixed the fuel delivery issue, however the car then was reporting erratic fuel pressure. With the car's ECU sending the car into limp mode if fuel pressure dropped outside pre-set limits it was frustrating to say the least...

    As part of the surge tank install the fuel sensor was moved to the end of the fuel rail, however this was corrected and moved off the engine.
    DSCN4285 by Eipeip, on Flickr

    When this job was done, the reported fuel pressure was reporting low again... Jiggled the plug and suprise, suprise, suprise normal pressure. Turns out that the ground pin on the plug was not crimped properly and all the playing around with the plug caused a dodgy connection.

    Fuel pressure before sensor wiring fix. The 'noise' on the channel should have been obvious, but for some unknown reason I did not think to check the sensor wiring:
    20170429 Fuel_Presure by Eipeip, on Flickr

    After sensor fix
    20170601 Fuel_Presure by Eipeip, on Flickr

    When you look at when the problem was first found, the fuel pressure trace is not 'noisy' and there was an obvious power loss. The 'dodgy' wiring was different as there was no loss of power and was intermittent...
    Car Health by Eipeip, on Flickr

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