6.0L Fuel pump?

[Fless]

Well, I got around to lifting the fuel rail. I lifted it up off the intake and looked for leaking injectors. I didn't have any drips, however, the bottom of every single injector was damp. I wiped them off, then depressurized the system and they were damp again.

I've never diagnosed injectors before.

I assume injector nozzles getting damp, when they are off might be my problem?

I also took intake off and swabbed behind throttle blade with my finger. It came out with damp soot and smelling of gas. This was after the truck had sat for two days w/o being started.

Lastly, I pulled the vacuum line on the pressure regulator and idled the engine. No gas cam out the vacuum port on the regulator. Somebody told me to do that to check the regulator. It passed the test.

You can clean/test the injectors by rigging up an input seal and a 12v battery; seal the input side and charge up the pressure with some carb cleaner, then give it the 12v. You can turn the 12v off and shoot more carb cleaner to see if/how much they leak. Might just need cleaning, which is essentially what you're doing. Lets you view the spray pattern too.

The FPR test might need a couple of minutes to show fuel coming out the vacuum port.

 

[Matthew Jeschke]

Gotchya, I may run the fuel pressure regulator test again.

I already had them pressurized just on the fuel rail. I don't think I should have seen any fuel coming out of injector at all... I'd assume they're bad (not dirty) since it's been hard starting since I installed the injectors new (built the motor). I only just now discovered they are letting some fuel through when closed.

I'm pretty well convinced they're bad injectors and I need a new set. I didn't know $42 was cheap for 8 injectors. Seems one OEM / ACdelco injector is around twice that for a single injector. I think I found my culprit.

My only concern is it doesn't cause damage if I keep running them this way till I find replacement injectors. It's leaking so very little but enough over time to cause a hard start / P0300 misfire.

I'm currently studying up on injectors. I may need a higher flow rate as it's possible once I get fully tuned I make over 400hp. Current injectors in theory only support 400.

 

[Fless]

If it's not inconvenient you could pull the fuel pump relay right before you shut it down, letting it run out of fuel. That way there wouldn't be much fuel pressure on the injectors while it's sitting.

 

[rockola1971]

Cheapest way I know of to clean fuel injectors is dump a quart of tranny fluid into a half tank or so of gas. Tranny fluid will lube the injectors and clean deposits too. Use to be my goto for cleaning carbs of everything from motorcycles, chainsaws, autos and much more. Still use it in my chainsaws and lawnmowers. She might smoke a little but its cleaning alot!