Audi 100 Starting Problems

[John Larson]

Geoff asked:  "Well you guys helped me get my Audi started before, so I 
figured I
would ask again. Well it finally quit firing (guess I got a bad
Distributor Cap from the junk yard) So I went out and bought a new cap
and rotor from Pep Boys. Installed it, and the car fires and cranks,
but before it will start something makes a loud bang. Also if I try
cranking it when the battery is low, after the bang it will stop trying
to crank at all. Could this be a started problem? And if so, where is
the starter on these vehicles. I heard rumors that you have to pull the
tranny on some Audi's to replace the starter, but I don't have the car
here right now and cannot look for myself. Any incite to what the bang
could be, or why I can get it started is appreciated.

Thanks!"

If the cap and rotor you bought aren't genuine Bosch, toss 'em and buy the 
correct parts.  The backfiring into the intake is caused by the wires being 
attached to the cap in the wrong order.  I know of no Audis where the 
transmission has to be removed to replace the starter, but that doesn't 
matter here because the symptoms you describe have NOTHING to do with the 
starter.  Shopping for Audi tune-up parts in the junkyard, or at Pep Boys 
for that matter, makes no sense at all.  HTH, John