2250 Carnage Pictures

[Rawze]

(04-09-2017 )Billdozer2 Wrote:  

(04-09-2017 )Rawze Wrote:  Nice video, but is not for ISX.

That's what I was thinking too. I'm like "This isn't an ISX fuel system."

What Rawze is saying is true. I did this leak down test about a year ago and found that my fuel pressure dropped maybe 100 psi in a minute. If yours is dropping 11,000 psi or what ever you said, you have a major issue. I'm really curious how the engine would run with that kind of leakage.

As far as the fuel system bleeding off, with my engine off, my fuel pressure sits around 5,000 psi. I've left the truck for a week and it is still at 5,000 psi. My truck fires right up, usually just after one engine revolution. The fuel doesn't continuously bleed off after the truck is off, at least not on mine.

Actually, the electric fuel pump will build roughly about 250+ psi or so with the key on and that is enough to fire the engine most of the time even if the rail has been bled to 0. If someone's fuel rail is leaking badly and it is mostly the bypass valve, and not injectors, then it may have very little symptoms. Still not good for it because it overworks the pump all the time causing unnecessary wear, lowers fuel mileage, and like any kind of hydraulic leak, heats the fuel unnecessarily.

If it is an injector, it can be subtle if it is not too bad, or be bad enough to cause hard-starts. A start-up that as it crosses the cylinder with excess fuel in it from injector leakage that causes a hesitation in rotation of the engine for just a very brief moment as it is cranking before it fires. Almost feels like a battery that is weak as it first starts to turn over sometimes. I have even seen an engine with an injector leaking so badly that it caused hydra-lock due to all the fuel dumping into a cylinder while it sat. Thats nothing to play with. That kind of problem can bend rods and cause some serious damage as it start to get real bad.