5ktq electrical problems update (not fixed)

[Dan Cordon]

> I trust the EFI readings because I have checked it multiple times vs a
> multimeter connected to various spots including directly to the battery.
> Every time I check the EFI is within a tenth (usually a few thousanths off
> to be exact) of a volt of the battery. Even so I do also check with my
> multimeter at the battery directly usually. No voltage drop at speed, it
> stays solid ± 0.1v from 13.5v no matter what the engine speed when all
> accessories are off. The cars main supply is fairly good it seems, the only
> problem is voltage supply to the ignition I think.
>
> -Cody Forbes

This one's really been bugging me. I love troubleshooting (hence why I
own some audis), but it seems that we don't have the data we need yet.
If the problem really is ignition, then why not measure parameters
effecting that system? I haven't seen any posts yet that detail voltage
or signal to the coil, or from the crank sensors. Those would be my
first two locations to measure. If those are producing/recieving the
signals expected, I'd then look to the wiring between them and the ECU.
Perhaps you could measure the signals *at* the ECU when driving. If that
all checks out, the ECU itself would be my next target. You've probably
swapped a spare in already though. In theory you could pull a few key
components off the car (distributor, coil, crank sensors, and ECU) and
do all the testing on the bench. To me it seems odd to put so much
effort in to looking at alternator wiring and such (which may help the
problem, but certainly isn't the most likely cause).

After all, the car starts.....I'm guessing that the voltage during
starting is far less than the 12.6 volts that have been causing problems.

Also, since the same symptoms existed prior to the EFI swap (wasn't that
posted at some point?) I would rule out the EFI system as being a
contributor. Of course, if you really wanted to solve things, you should
talk to Javad and see about getting a beta version of the direct fire
setup :o) That would pretty much get rid of all the current ignition
components, except the two crank sensors. Just a thought.

--
Dan Cordon
Mechanical Engineer
University of Idaho - Engine Research Facility