On the driver's side fuel rail, near the middle of the rail should be a small vacuum hose pushed onto the fuel pressure regulator. Pull off the hose and start the engine, see what your fuel pressure is. You can plug the vacuum hose with a small phillips screwdriver if you want, but you're only gonna start the engine for a few seconds, so it's not important.

 

UPDATE-At least my truck isn't fucked up.

I bought a cheap little fuel pressure gauge from harbor freight and after a bit of wrestling with it, I got it working. It's reading around 49-50 with the key on and a tiny bit lower with the engine running.

I suppose that means the sender for my gauge is messed up. I'm still at a loss as to why it's reading right, just 10 psi low.

 

Mine read 10psi too high....

 

interesting. Well it sucks having a $170 gauge that reads wrong, but I guess it's better than losing a motor when spraying.

 

do you guys have the little black box gauges or the newer ones? ive got an extra little black box that i will sell for cheap if that may be the problem. i just gotta make sure they both work the same on my truck first haha

... totally forgot i was searching for something when i seen this and that its old...... boo for me

 

hate to bring up an old thread but my fuel pressure reads the same. and i have the same gauge. 50 key on, 45 engine running, because i still have a FMU with my supercharger kit im seeing over 100 psi at full boost!