Fuel Pressure

[6speedsd]

Once the key is off, is FP supposed to hold, or drop? I've heard both. Checked mine today and KOEO built up to about 48ish lbs. Idling was at 50. Turn key off and it dropped to zero pretty fast. Like I said, I've heard both. Just wondering which way was correct.

 

[Big Angry Hillbilly]

I've never seen it hold for very long on any truck I've worked on or diagnosed, even factory showroom new.

 

[6speedsd]

That's what I figured. Like I said, I've heard both sides, so I wasn't sure which was correct.

 

[Evan ogre44]

ive seen it hold for about 2-4 seconds but straigh to zero after that

 

[6speedsd]

As soon as I turned the key off, mine started dropping. Within 10 seconds it was to zero. Probably didn't take that long to be honest.

48 psi is acceptable for KOEO right? I've always heard anything under 50 should be looked into, but I thought that was while running. Idling I saw right at 50. Blue spring kit is on the to do list here soon.

 

[SICKS LITER]

they dont usually hold pressure. that pressure is a little low, definitly look into the updated fuel pressure regulator kit.

 

[Big Angry Hillbilly]

Unless you have the proper gauge with the goofy long hose you need to be measuring fuel pressure with the truck under a high load wide open throttle condition.