ed hess
race or get outta the way
Symptom:
start truck cold.
Runs and idles fine.
wait a few seconds
engine stops.
Looking at this on dm frame by frame you can see
frame no drp rpm
618 drp rpm=925
620 drp rpm=950
622 drp rpm=925
624 drp rpm=925
630 drp rpm=950
632 drp rpm=950
635 drp <------- 5 frame gap in drp starts here rpm=925
636 --- rpm=925
639 --- rpm=900
640 drp <------- gap in drp ends here rpm=900
641 --- rpm=900
642 --- rpm=850
643 drp rpm=850
644 --- rpm=850
645 drp <------- 2nd gap starts here rpm=800
646 --- rpm=750
647 --- rpm=750
648 --- rpm=700
649 --- rpm=650
650 drp <----- 2nd gap ends here rpm=650
651 --- rpm=600
652 --- rpm=525
653 --- rpm=550
654 drp rpm=425
655 --- rpm=275
656 --- rpm=275
657 --- rpm=0 <----mention something about mom & dad here
The O2 mv has a steady drop from frame 635 at 808mv to frame 656 at 31mv. then it finally stalls at frame 657.
given the symptoms shown above I am wondering if the cause of the stall is fuel cut off mode. The cd says
"fuel is not delivered if no reference pulses are seen from
the distributor"
So the questions here are.
where does the reference pulse come from?
Is this the same reference pulse i.e. drp as seen in dm?
How long of Not Seeing a Pulse is enough to trigger fuel cut off mode?
What am i missing?
Am I barking up the wrong tree.
You all know ive been chasing an odd problem for a long time. The only things i havent changed are pickup coil, and fuel pump.
It took a while to type the dm stuff above. It clearly shows 2 gaps in drp reference pulses.
If you prefer i can email you the dm file. graph curves using rpm, advance, DRPmS, and O2mV. And then expand the view at the very begining.
ed
start truck cold.
Runs and idles fine.
wait a few seconds
engine stops.
Looking at this on dm frame by frame you can see
frame no drp rpm
618 drp rpm=925
620 drp rpm=950
622 drp rpm=925
624 drp rpm=925
630 drp rpm=950
632 drp rpm=950
635 drp <------- 5 frame gap in drp starts here rpm=925
636 --- rpm=925
639 --- rpm=900
640 drp <------- gap in drp ends here rpm=900
641 --- rpm=900
642 --- rpm=850
643 drp rpm=850
644 --- rpm=850
645 drp <------- 2nd gap starts here rpm=800
646 --- rpm=750
647 --- rpm=750
648 --- rpm=700
649 --- rpm=650
650 drp <----- 2nd gap ends here rpm=650
651 --- rpm=600
652 --- rpm=525
653 --- rpm=550
654 drp rpm=425
655 --- rpm=275
656 --- rpm=275
657 --- rpm=0 <----mention something about mom & dad here
The O2 mv has a steady drop from frame 635 at 808mv to frame 656 at 31mv. then it finally stalls at frame 657.
given the symptoms shown above I am wondering if the cause of the stall is fuel cut off mode. The cd says
"fuel is not delivered if no reference pulses are seen from
the distributor"
So the questions here are.
where does the reference pulse come from?
Is this the same reference pulse i.e. drp as seen in dm?
How long of Not Seeing a Pulse is enough to trigger fuel cut off mode?
What am i missing?
Am I barking up the wrong tree.
You all know ive been chasing an odd problem for a long time. The only things i havent changed are pickup coil, and fuel pump.
It took a while to type the dm stuff above. It clearly shows 2 gaps in drp reference pulses.
If you prefer i can email you the dm file. graph curves using rpm, advance, DRPmS, and O2mV. And then expand the view at the very begining.
ed