Loosing fuel pressure

[rizzamike]

Loosing fuel pressure, Can’t find any leaks? Once I start my truck the gauge reads 0 and if it let it idle there for a while it will eventually climb to mid 50’s (a few minutes idling) and then stay constant and even at wide open throttle it will only drop to 50psi. I recently changed the blue spring, the one that was in there would only give 40-42 psi the new one gives me 55psi, the old one was just over a year old. The install was straight forward doubt I messed that up but there is no fuel leaking anywhere.

First I was getting and still am horrible fuel mileage so I installed a fuel pressure gauge
Found out I was low fuel pressure low 40’s
I changed fuel filter at every oil change but I decided to change them again to see if it would help no change
I thought it was the pump because the upgraded blue spring was only around 1 year old so I replaced the pump no change! So I wasted money on the pump
Also started to notice the fuel pressure would build very slow but stay steady
Installed a new spring and pressure builds to 55psi but still builds very slow and will only build at idle or low rpm not driving around

What can this be? Could the low fuel pressure be what my horrible MPG is related to?

Thanks for your time any input is greatly appreciated! I need this fixed asap! The fuel mileage is killing me and I don’t want to do any more damage to the injectors!

[southend]

Is it a mechanical guage? Your truck cannot run on 0 psi fuel. Low fuel pressure would kill injectors real quick. Maybe your guage is taking a vacation? Many things csn cause bad fuel mileage, probably including low fuel pressure.

Sent from my phone that somebody didn't help me get.

[rizzamike]

Thanks for the response, I decided to go to the dealer yesterday and purchase a new regulator kit, I was surprised to find what was wrong with my truck! I totally see it as my fault for not looking but a year ago when I updated to the blue spring I just purchased the spring not the kit, changed the spring and have been running it ever since. It was missing the O-ring or seal that mounts to the plastic sleeve in the housing. My truck has always run great no issues except for bad fuel mileage that was why I decided not to long ago to purchase a fuel pressure gauge to see if it was a possibility, Looks like that was my main problem! I fought with it for weeks new filters, replaced the pump, I even added the bb to the blue spring that was when the pressure gauge would read 0 then slowly climb and hold but without the bb it would be a steady 40-45. Last night once I changed the complete kit that I cheeped out on the first time the pressure sored to 70psi with just the key on and even stayed there once the truck was started and at wide open throttle it still only drops about 5psi. Finally it is working the way it is supposed to! But now I am even more concerned! How has my truck rum ok for this long on low fuel pressure? It has been more than a year! I changed the spring a year ago and the thing was installed wrong from the previous owner! It has been running this way for over 2 years! When I got the truck I got 14-15mpg city and 17-19mpg highway, I have only been getting 11-12mpg for a while!
Are my injector shot now?
Would this have done damage to something else?
Should my mileage improve?

Thanks for any input, I needed to find this out! I spent almost $9000 in fuel last year!

[southend]

Thanks for the update.

Sent from my phone that somebody didn't help me get.

[twoicebergs]

Good catch for round 2. As far as possible damage to injectors, only time will tell. Since you haven't experienced any other issues except low fuel economy, you should have your answer in a few tankfuls.