Need some help, truck just started doing this...hard start condition, and p0171,p0174, truck is 2003 3.0 flex, new plugs,wires coil, new y pipe and cats, new starter,alternator new fuel filter, fresh oil change. First start in morning hard start, then starts easily after that. If sitting fir 8 hrs when I'm at work, hard start again. Truck does not have frame mounted ffs sensor. Going to replace fuel rail damper next, and possibly the regulator. Everything I read says it's on the fuel pump, but itvlooks to me to be on the railed, anyone know fir sure? After that will be fuel pump...

 

Try cycling key on and off 3 times before first start
That will Prime the fuel system 3 times to get 30psi pressure back assuming it was 0psi after sitting for 8 hours

But the that wouldn't cause the codes
P0171 System too Lean (Bank 1)
P0174 System too Lean (Bank 2)

Since both sides of the engine are effected its either an upper intake vacuum leak or a fuel pressure issue
Engine is not actually running Lean, thats not what those codes mean, just FYI

They mean computer's calculated open time for the injectors was not long enough and computer is having to open the injectors 20% longer to get a "good burn"
So an air leak or lower fuel pressure

3.0l should have a fuel pressure test port on the fuel rail
60psi is expected running pressure on 1998 and up Rangers

Pulse damper has a vacuum line attached, check it for gasoline, if none found its is OK

In 1998 and up the Fuel Pressure Regulator is in the gas tank with the pump, part of the pump assembly

 

I should have mentioned thechard start is only with E85, I tried filling with regularcgas, truck starts fine., I've already checked for vacuum leaks, none were found.

 

Yes, that info is helpful

Is this the stock engine with stock computer and injectors?
Look at the VIN, 8th digit should be a "V" for flex fuel, "U" is gas only

The Lean codes would for sure come up running E85 in a regular gas vehicle
Need to add A LOT more E85 fuel to get a good burn, 25-30% more

What makes a vehicle "Flex Fuel" is the computer and injectors

E85 also has a hard time starting cold engine with temps under 50degF
Which is why winter fuel is usually E70

But that doesn't explain the Lean codes
If you have the stock flex fuel injectors and you don't Lean codes with gas only then I would look at fuel pressure first

 

Yes it is a flex fuel Vin v , I have not checked the injectors yet, but the truck was running fine for the past year since I bought it, on both the flex fuel, ND reg gas...I will be checking the pressures as soon as I get a day off from work.

 

If its been fine then not the injectors, yes test fuel pressure next, 1998-2011 Rangers use 55-65psi running fuel pressure so 60psi average, I wouldn't think you would see a problem unless you were down under 45psi
Fuel Pressure Regulator is in the gas tank with the fuel pump, part of the same assembly

 

I'm not sure if the 01's use the same electrical run to the fuel pump as the 99's, but it might be the issue i had a while back(99 3.0L). Check to see if there's a connector under the cab on the driver's side about in line with the rear of the drivers seat. It would be on a mount attached to the frame rail. IF it's there then it could be grounding to the cab along the run to the fuel pump just past that mount. I fixed it with liquid electrical tape, electrical tape, and a piece of roof membrane. But realistically so long as you seal the wire so it can no longer arc then it might fix the problem.


nevermind, that sounds more like a computer problem.