Problem With Misfiring.......

[shufti]

hi guys

i own a 2000 a6 avant 1.8T which has devoloped a misfiring fault. it generally drives on average at 30mph max with my foot to the floor with intermittent bursts of power that last no more than a couple of seconds.

has anyone had similar problems or from the codes below can anyone help me in locating the problem, i can't afford to give it to audi so will try and replace the relevant parts myself once i know what is causing the problem.....

i've had suggestions of the maf filter or coil packs that could be causing this but these were suggested before i done the scan... i was able to arrange a vag-com scan today and this is what come back........

vag com - faults found......

17544 - Fuel Trim: bank 1 (add) system too rich - P1136

17536 - Fuel Trim: bank 1 (mult) system too lean - P1128

16684 - random/multiple cylinder misfirwe detected - P0300

16685 - cylinder 1 misfire detected - P0301

16687 - cylinder 3 misfire detected - P0303

16688 - cylinder 4 misfire detected - P0304

16686 - cylinder 2 misfire detected - P0302

17925 - main relay (j271) electrical malfunction - P1517

18010 - Power Supply Terminal 30: voltage too low - P1602

18034 - Power train Data Bus: missing message from TCU - P1626

17834 - EVAP Purge Valve (n80) open circuit - P1426



i called audi with the details of the main relay fault (17925 - main relay (j271) electrical malfunction - P1517) i thought that replacing this would be as good a place to start but after calling 3 dealers nobody could tell me what relay this is! anyone out there know????

thanks

[Laseron]

Oh man.... Sorry brother but I don't have books on the 1.8T. Try to buy a Bentley's service manual for you ride. I have one and its been very helpful.
Main power relay? I don't know.... The lean / rich codes are usually the MAF. Coil packs also make sense for misfires. I think there was a recall involving coil packs around 2000. You may want to check this out.
Good luck!