1987 5k CSQ starting problem - long

[Chander Balakrishnan]

Fellow listers:
This is a bit of long story...  my brother-in-law's 1987 5k csq has been
giving problems for sometime now.  The symptoms are as follows:  The car
would not start when cold or for that matter even when it is warm outside -
the problem began in Fall when it had not become so cold here in Chicago,
yet.  Jump starting the vehicle with another  vehicle would enable an almost
immediate start.  I finally took it to our trusted mechanic who did the
following and is still stumped.


He found several problems when he inspected the car.  The ignition/starting
key switch were hard to turn and the starter would only energize with the
key turned to the extreme, nearly twisting the key off.  The battery was in
a very discharged state from extended cranking and the starter was also
failing from excessive cranking.  The spark plugs were well worn and the
ignition cables were old and deteriorating.  The ignition switch mechanical
and electrical portions were replaced.  The starter was replaced with a
remanufactured unit.  The battery was charged fully and tested OK.  The
alternator output was tested and was found to be OK. The ignition coil was
tested for proper resistances and found to be outside of tolerances.  It was
replaced with a good used unit. The sparkplugs, distributor cap, ignition
cables and ignition rotor were replaced.  Compression was tested also at
that time and found to be OK.  Fuel pressure was tested and found to be in
spec.. Fuel delivery was checked and also found to be in spec..  The fuel
mixture was properly tested and found to be within specifications.   A used
fuel pump power supply relay was installed as a test measure. The cold
starting system including acceleration enrichment were tested.  The cold
start valve is operated thru the engine ECU and has a slight delay in
energizing the cold start valve.  The duration of the initial operation of
the cold start is within the specification of the temperature/time operation
graph.  It also operates to provide acceleration enrichment and is operating
properly.  An extended test on the operation of the fuel pump power supply
and cold start valve were conducted using two small light bulbs. One bulb
indicated the power supply to the fuel pump circuit and the other indicated
power supplied to the cold start valve.  Upon starting the vehicle in very
cold conditions, the fuel pump is working fine and the cold start valve
powers up initially.  If when first started the engine doesn't start, the
cold start valve doesn't get any more current without stopping cranking and
waiting for an undetermined time.  Repeated attempts to start the engine
results only in draining the battery. But if it is jumped with another
vehicle, it starts right away.  Can anyone give us a clue as to where else
to look ? TIA.



Chander