[s-cars] Intermittent cutout

[Dave Forgie]

Bob, in frustration (no doubt) stated:

"Measured voltage across FP.  Zero.  Told wife to crank 
engine.  Voltage rose to ~11.7 or so volts and then engine fired and 
voltage went to a rock steady 13.58 volts and held there until engine 
died again (and voltage dropped to zero) after perhaps a minute."

Bob: The ECU controls the J17 fuel pump relay.  Until it gets a signal
from the cam position sensor to tell it that the engine is cranking,
there would be zero volts at the fuel pump.  While cranking, the
alternator is not putting anything out (and in fact, may be on the load
reduction circuit) so the voltage during cranking would be battery
voltage, i.e. 11.7 V.  Once the engine fired and the alternator is
working, the output should be in the 13.7 V range (minus the small
losses from your battery-relay system) so 13.58 V makes sense.  Also
once the engine is running, the signal from the engine speed sensor is
used to tell the ECU that it the engine is still rotating and that its
okay to keep the FP relay locked on. 

So the obvious question is why the fuel pump is being cut-off.  To me,
the reasons could include: 

1) Joey P.'s ECU socket suggestion, i.e. the ECU has a problem.
2) There is still a problem with the J17 FP relay 
2) The socket and J17 relay are fine but the engine rotation signals
from the CPS or the engine speed sensor (G28) are bad.

Since you are getting a CEL and the 00513 code keeps coming up, I think
the ECU is telling you something - its the G28 engine speed sensor.  I
think it is time to swap the Crank position sensor and engine speed
sensor pair from the running car to the problem car.  I believe that
will be the answer.

HTH

Dave F.