What psi am I looking for when I check fuel pressure? And well, what are the proper steps to check fuel pressure? And where in relation is the fuel regulator? Is that close to the fuel vapor canister and connected to vacuum lines? If that's what it is it is brand new already. I guess, long story short everything in the engine bay is brand new except the engine. New heads, gaskets everywhere a gasket is located on a 4.0L, spark plugs, wires, reconditioned and tested fuel injectors, maf, fuel filter, anyways, anything in the engine bay that was bad has been replaced. And anything else that wasnt bad but needed maintnance has also been replaced. Hahahahahahaha still a long story but hell, I only ask this because im curious and in no real hurry to fix. By the way, my timing is nuts on. 147xxx miles before rebuild, checked timing chain and related items while I was in there, everything was fine and in spec but I still messed with the adjustments and lubricated them and put them back to spec yada yada yada, smelled like fuel before rebuild and smells like fuel after rebuild. Fuel pump whined before fuel pump still whines. Hahahahaha so yeah my real question is why, and what steps should I do to go about fixing it? Thank you so much guys!