Back to Forum
Post a Response
    Nissan Skyline GTR 2.6 twin turbo '99-'02 RB26DETT Archived Message

    Posted by Nick Bell on May 19, 2008, 12:03 pm

    Hi All,
    Looked at this for garage. No data for it, or code read/live data facility. Idles lumpily and no 'pulling power'. Reported by owner that problem getting worse. Said I would do some generic checks. Plugs 1 & 2 seem to show lean, with white ceramic insulators under electrode, but 3 to 6 are sooty. Noticed this seems to have linked throttle bodies, in pairs, between inlet manifold and head.
    Compared lean and rich cylinders; fuel inj. durations same at 1.9mS idle, and coil secondaries appear the same. CTS only got to 1.25V when hot. Would have expected lower then this, say .5 to .8V. Found engine speeded up when sprayed carb. cleaner in several places near inlet man./throttles areas, indicating leak. Should there be NO perceptible change, even near throttle valve spindles?

    In. man. vac. bit low at 16 to 17 inches Hg.. Cam belt was changed a while ago (5000 miles).

    O2 sensors appear to be in, or very close to, turbos. One is switching badly. That is, slowly and hardly going lower than 0.5V. Have recommended replacement, but feel this isn't the whole story!

    HCs reported to sometimes go up to 1400, but customer says exhaust gets very hot suggesting lean??

    Fuel pressure OK at 2.5 to 3 bar (vac. pipe to regulator on or off) and MAFs peaking at 3.5V to 4V (Bosch ESI suggests vaguely 1 to 3).

    TPS 'scoped showing typical waveform and no dropouts.

    Should manifold come off to investigate leaks or is this expected and a 'red herring', and is a compression check in order?

    Would appreciate some help with this one. Thanks in advance,

    Regards,
    Nick Bell

    Message Thread:


Copyright © uk autotalk