No business sells a product for no profit. Especially if they are expected to warranty it. If parts were sold at cost, do you think labor rates would remain where they are now? If parts were sold at cost, would you be ok being charged labor time for the time spent finding and ordering the parts? And performing the paper work for receiving them, recording them and paying for them?

Profit is a dirty word to most people.

Your high pressure oil readings are too low and your fuel pressure reading is incorrect. Those should only have 50-60psi of fuel pressure. Maybe slightly more, but well under 100 psi of fuel pressure. Your high pressure oil needs to be over 400 psi for the truck to start. What high pressure fuel access port are you referring to? You removed the ICP to test the high pressure oil or used a scan tool and data? It sounds like you have a high pressure oil leak somewhere, but some of your testing and terminology are confusing. Do you have a way to air test the high pressure oil system? If not, I would remove the valve covers and inspect the stand pipe and dummy plug o-rings. They are pretty common to cause low high pressure oil readings.

The most likely cause in your situation is an ignition arc. It sounds like the fuel rail was probably leaking and an ignition coil arced. Either that or you pinched a power and ground wire somewhere and that sparked in the presence of gas fumes.Those would be my guesses.

I guess I would start with the procedure someone else mentioned to figure out the gear ratio of the rear end

Is it a former mud truck or something?

Changing the gear ratio could help, if that’s the problem. Is the transmission shifting through all of the gears? Do you know what gear ratio is in the differential(s). If it’s 4wd, you will have to match the gear ratio in the front and rear differentials.

Rock auto

Did you change the oil before or after the problem started? Did you use a Motorcraft oil filter with the original cap? We have seen several hard/no starts on 6.0 Powerstrokes due to aftermarket oil filters. Also, make sure you oil level is correct. What fuel pressure and high pressure oil pressure are you getting? How are you testing these?

Not always. It takes a lot more power to turn over an engine than it does to turn on a radio and some lights. Quite often a battery has enough power to turn on accessories, but not enough power to start the engine.

Male customers want to deal with a female advisor more than a male…

I’m not so sure about that part. We have two women service advisors and customers will sometimes question them, but then I tell the customer the same thing and everything is ok. I don’t know for sure if it’s because they are women or because they don’t know how to fix a vehicle. I don’t think most service advisors know how to fix a vehicle, though.

We have put liens on vehicles that we’re financed and vehicles that weren’t. Neither involved what you mentioned. The dealer that financed the vehicle didn’t want to pay the full bill, we put a lien on it and sold the vehicle. The last one we did was owned outright by the customer. We put a lien on the vehicle and now have a title in our name. No court involved.

It doesn’t matter if they own it out right. A mechanics lien overrides almost everything. We put a lien on a car that the customer still owed on. The dealer attempted to repo the car, but we wouldn’t let them unless they paid the bill. For whatever reason the car dealer let us keep the car and we sold it for double what the bill was on the car

Verbal authorization is allowed in some states. Written is always better. That still doesn’t stop a customer from being a scum bag and abandoning the vehicle after authorizing the repairs. If the work we are doing approaches the value of the vehicle we will get a 50% deposit on the repair. If the work is much less than the value of the vehicle, and the customer doesn’t pay, we put a lien on the vehicle and sell it and are allowed to keep the profit.