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Have a 99 7.3l with extended crank with no codes. If I turn key off for 30 seconds and try to start crank is extended. If I leave key on with engine off for 30 seconds engine fires right up. Have another 7.3l here compared readings and they are the same. I suspect HPOP but would like that comfirmed.
No difference. It's 75 here today. Engine will start after extended crank but it's slow to build oil pressure. Like I said before if after running I turn engine off but leave key on the oil pressure drops slow and after 10 minutes it fires right up. If after running I turn engine off with key off after 30 seconds oil pressure drops to 0 psi and engine has extended crank.
So, if you leave the ignition on for a extended length of time it will start? Sounds more like a low fuel pressure issue to me. Check fuel pressure, it could be a weak low pressure fuel pump or clogged fuel filter. Leaving ignition on shouldn't affect oil pressure but it may be running fuel pump and letting it build pressure.
Happy New Year. Yes fuel pressure is good. On my scanner I notice the high oil pressure takes a bit to build. What gets me is when turn engine off but leave key on I can let it sit for 30 minutes and it will fire right up. If I turn key off and let it sit for 30 seconds it has extended crank. It's like the oil is draining from rails. Doesn't make sense.