More on non-starting Ur quattro

["Jim Haseltine" <Jim@ur-q.freeserve.co.uk>]

To recap:
Subject, 1988 Ur quattro - MB engine.

Symptoms - Engine turns but will not start, no spark at plugs.
The situation as of last night was that I thought that the problem was with
the distributor cap and rotor arm, there was a spark (loads of them) at the
coil but none at the distributor cap plug lead sockets.


A new distibutor cap and rotor arm made no difference because this morning I
couldn't get sparks at the coil either.
I've been working my way through the tests on Scott Mockry's web site,
the ignition coil driver module checks out ok as do the coil resistance
checks. The distributor Hall sensor sits at 4.88v and drops below 1v when
the engine is cranked.

I've tried pulling the codes but all that I'm getting is the engine check
light on continuously. The ECU is fitted with an aftermarket 'tuning' chip
of unknown origin.

I'm now waiting for the battery to recharge...

Still stumped

Jim Haseltine