7.3 trouble starting

[mdkallam130]

My issue began after the truck had sat at the fire station for 24 hours. When i went to leave duty after my shift the truck would just crank and crank and finally fire up. The starter was turning plenty fast enough with almost brand new batteries. truck just cranked and cranked and the motor started to change sound almost like it was building up enough pressure to sustain running. once it fires up it runs fine with no codes and no issues starting after driving it with the exception of just a little longer cranking.

this morning however just cranked and cranked with no sign of it starting up... batteries dropped to low so no possibilty of cranking after that point. glow plug relay and glow plugs replaced recently. been in the 50s in the mornings here. Any ideas on what might be occuring/

[Ford7three]

When was the last time you changed you oil? 50* shouldnt be causing issues but there is a possibility the oil is dirty and can not flow up fast enough. If your weather is expected to get colder I would recommend going to a lighter synthetic oil to make sure that even when its cold it will still flow.

[mdkallam130]

Oil was changed last tuesday using rotella 15 w 40.

[Ford7three]

Can you hear the injectors clicking when your cranking on it?

[mdkallam130]

havent really listened for the injectors while cranking it. my attention was geared more towards listening to make sure the starter was turning fast enough. when it does fire up you can hear it build up almost like its not getting fuel and then starts to get fuel to it and then fires up

[Ford7three]

Some times there are drain back issues where after sitting the oil will kind of drain out of the resivoir and then when you go to fire it up it has to fill the resivoir then fill the heads which is why it sounds like its cranking then finally firing up.

[mdkallam130]

that sounds like a very plausible scenario for what may be causing the issues im having. when i changed the oil the other day should i also have added oil to the hpop resevoir? if so i did not do this and did not think to do that. Could be very essential in driving those injectors. i will check this and reply back to you. thanks for the help

[Ford7three]

Its not needed to top it off as there is a Low Pressure Oil Pump that fills the resivoir where the High Pressure Oil Pump draws its oil from.

[mdkallam130]

The low pressure oil pump wound up being the culprit for this problem