I have about 5 different older gentlemen mechanics, with the professional tools, helping to do the work on this truck, all of them are very capable and knowledgable about cars and trucks. I got suckered when I bought this truck, from a co-worker and these guys are just trying to help me out; it literally broke down on me 3 days after owning it. 2 months now owning this truck i might have driven it 4 times. Believe me I get it, I am beyond frustrated with this and the money in parts that it is costing me. Thanks to this "money pit" I couldn't afford a decent Xmas or Bday for my son. I am thankful for the kindness of these men not charging me labor and making sure that everything that was and is wrong with this POS is done and I and my son have safe reliable transportation. So sadly the only way I have been able to help is to google my brains out to try and help figure things out or give suggestions.

 

I think a cpi will just barely run at 52lbs with a lot of fuel trim but not at 40lbs. If it wont HOLD 55 check again at the fuel filter. If good; its most likely the fuel press reg. If it checks low at the filter its the pump or pulsator.

 

They did replace the fuel pressure regulator and they have checked the filter which is fine. When they checked the manual the correct psi is supposed to be at 60 and it registers at 40. When left in the garage it will start, but when left outside when the temps drop to below freezing or zero it won't. They are going to be replacing it in the next few days.

 

60psi at the service port is bare minimum for the engine to start and run properly. The poppet valves will not open and squirt fuel below ~43psi. Whatever pressure the regulator is set for, it will maintain that pressure provided the pump can produce at least that amount of pressure. In other words, if the maximum pump output pressure drops below what the regulator is set at, the injectors will only see what the pump can provide. As mentioned, you need to check maximum pump output pressure at the fuel filter to see if the pump can meet the requirements of the regulator.

 

I am so done with this darn thing!!! They were right and the fuel pump was pretty shot, but after replacing it the dang thing is still doing what it did before!!! After it ran fine yesterday, went to start it this morning and it wouldn't kick over. Granted it was about 20 below zero, but with a brand new battery as well as the other stuff it should have started. The only way this truck will start is if it is left in my friends garage. Im 700$ in on parts and I can't afford to keep doing this! Im beyond frustrated!!!