05 c/k fuel pressure regulator

[87racer]

Hello and thanks in advance for any help. i have an 05 k 1500 with 5.3. i suspect the fuel pressure regulator as it is running rich and giving a repeat p0300 code . along with others. upon inspection i could not find a regulator on the engine or in the line. is this controlled by the pcm?? the thing runs like crap.... thank you

[Jeremy-WI]

Its on the fuel rail and has a vacuum line connected to it, it should be on the left side close to the middle

[87racer]

i am just not seeing it. it only has 1 line from the tank and 1 back to evap and no visible press reg??. i got a 171, 174 too lean bank 1 and 2 . also p0300 random missfire. any ideas?? thanks

[jyount]

If you got lean on 1 and 2 either you have an upstream vacuum leak effecting both, or your fuel pump is probably on its way out. It isn't very common for the regulators to stick open and drop the pressure that much.

Spray some brake kleen, carb cleaner, etc around the intake and throttle body area. It is sometimes hard to diagnose leaks under the intake, as they have foam blocking at the front and back between the valley and the intake. May clean the maf sensor off too.

[87racer]

THANKS, I agree with ya on the vac leak. did a scan and the st trim % dropped when i sprayed brake clean on the intake. fuel pressure is 57 to 60. i hope the gaskets work!!

[87racer]

actually, intake was warped. sucking air. changed it to a dorman(nice piece) . still missing some . going after a few injectors as i did a test and 2 of them didnt drop as much. hope this works. i am sick of this thing!! thanks for everyones help