Life approaching 500K is a never-ending adventure. October's incident with the gas pedal still working out fine.

Last night, truck shut off like a light switch. Plenty of crank - no run. Small trail of oil droplets leading to where I came to rest. First sign of any oil leak - have been parking on top of snow for quite a while now, would certainly notice fresh leak activity. Trying a few starts created a small puddle underneath - not a large one. I added a quart to get it back to 'operating area' on stick - it is cold-start blue smoke season and I do know that smoke is actually oil leaking past really really cold, quite old o-rings on the injectors, so oil was a tad low, but not off the stick low. No change -

No oil pressure on gauge.

Optimistic scenario is just a blown line ending at HPOP or at head. Or maybe just a broken/cracked line?

Pessimistic scenario is the HPOP would have pumped out way more oil out of a bad / completely broken line.

Another scenario is one failed injector seal - HPOP can't create enough pressure for truck to run. But then where is small oil leak coming from?

More mysterious scenarios to me are leak from low pressure system but I can't quite conceptualize interaction with failure to run. Even deeper problem with head gasket perhaps? It's 19 years later, anything is possible and it could be That Time with this truck.

On the optimism front - could a small leak simultaneously make it impossible to create enough pressure to run?

Shop #1 is diagnosing as I type. Shop #2, which currently has a 503K 7.3 under repair for similar issues and def. has plenty of experience in this whole system, laid out the more pessimistic scenarios for me on their kindly call back.

 

What does the HPOP make for pressure while cranking?

 

Still waiting in line for a scanner connection. Maybe in another hour.

Someone mentioned to me that the gauge on the dash reflects the low pressure system ... maybe low pressure pump failed?

I always assumed that gauge was tied in with the HPOP.

 

Easy check, is the HPOP full of oil? This could point to the LPOP either supplying oil to the HPOP or not.

 

Easily could just be an o-ring blown on an injector. not enough pressure to fire once the system is open like that. Hang tight and see what the ICP is when they get the scanner on it.

 

My readings have been around 500 and they quickly spike up into the 2000's on start up then come back down.