[s-cars] Diagnosing 1.8t coil pack failures

[Dave Forgie]

Well, after a year of driving my 1.8t coil pack conversion experiment, I
finally (inevitably?) had a coil pack fail. Its been coming on for
awhile, i.e. some missing/ hesitation under boost (24 psi plus) but
nothing in "normal" driving.  Just like a "real" coil failure mode. 
Like the OE system and a POS failure, you can't find the offending
cylinder until you get a total failure, i.e. a failure at idle.  As a
result, diagnosing which cylinder is the problem is the same as tracking
down a OE POS channel failure:  1) Remove the injector cover 2) Start
the engine (in neutral with the hand brake on) 3) pull the injector
connectors one at a time. Since you will be going from a 4 out of 5
cylinder mode to a 3 out 5 mode, it is very clear which cylinder has the
problem.  In my case, based on other failures, I was willing to bet it
would be no. 5.  Wrong:  No. 3.  Solution: disconnect the coil pack from
the harness, pull coil pack, remove rubber "seal" ring from dead coil
pack, add seal ring to new coil pack, insert new coil pack (to engage
the hex part of the plug), reconnect to harness, start car. 
Purrrr.....Total time from removing injector cover to finish: 5 minutes
(and some of that was wiping dirt off the fuel rail).  Now to find out
whether the 115 R coil packs are really any better.

Dave F.