85 4kq intermittent loss of electrical power

[SJ]

> From: "thorkq" <thorkq at gmail.com>
> To: <quattro at audifans.com>
> >
> > engine starts cutting out.
. But then the cutouts got longer and more
> > frequent. I noticed that while the cutout was occurring I would seem
> > to loose power to my accessories, like the turn signals, and the
> > battery icon on the dash would light up. I would coast for a few
> > seconds and everything would be fine, engine starts running, turn
> > signals work, battery icon goes off.

**** First thing to check is the fuel pump electrical connections. On my 85
4k, the FP connections were spring type clip-ons. The contacts would heat
up, expand, and lose electrical contact -- fuel pump would stop. After
sitting along the side of the road for 10 minutes or so, the contacts would
cool off, shrink, and electrical contact established.
I removed the electrical connections, cleaned them, put them back on AND
ADDED A WASHER AND NUT. That fixed the problem.
If its not the pump, as you suggest, because electrical stuff dont work, how
about attaching a wire to the coil B+ connection and connect to a voltmeter
inside the car. If the cutout occurs and you see no voltage on the meter .
.then you know its most likely the ignition switch problem.

Intermittant problems are a bitch to find. If it was me, I would attach
several wires to strategic test points(make one of these a good ground) and
run the wires inside the passenger compartment. (running 10 wires is just as
easy as running 1). Put small bolts into a piece of wood and terminate each
wire at a bolt, and label the bolt locations with test point information.
Use a systematic approach . .linear path for current (voltage) thru system.
When the car fails again, you can quickly check each wire for B+.
For example: #1 is battery, #2 is battery side of ign switch, #3 is run side
of ign switch, #4 is B+ side of Ign coil,  . . .etc.

When a failure does occurrs, and you get voltage at #2, but not at #3, you
know its the ignition switch.
Oh, and use a lamp bulb for checking voltages, in addition to the voltmeter.
Voltmeter has a high impedance and may show 12 volts . . .like thru a 1 meg
ohm resistor(bad contact) . .but 0 volts when you put a load on. The light
bulb wont light up if there is a high resistance connection.
I've been fooled more than once with a high resistance connection which
shows 12 volts on the meter. And you end up wasting a lot of time chasing
your tail.

Oh yes, and redo ALL your ground connections. No ground, no current flow - -
but the voltmeter will show 12 volts everywhere.
Inspect each ground cable/contact . . .unbolt it . .clean it . .clean the
chassis/engine mounting surface . .bolt it.


SJ
85 Dodge PU, D-250, 318, auto
85 Audi 4k - - sold but still on the road
88 Audi 5kq
90 Audi 100q