My fp is normally between 6 and 7 psi at idle, then drop's down to around 3 under wide open. Today I was sitting at a drive through and noticed the needle was going back and forth from 5.5 to 6.5. I have never noticed this before. All the other gauge's are steady. After I left the drive through and romped on it, it droped down to 3 like alway's. Got back home and it's still doing it. You guy's think there's a problem, or is this quiver normal and I just never noticed it. It seem's to do it after idling for more than 30 second's.

 

Houston we have a problem. Get it replaced ASAP.

 

Get what replaced.

 

Lift pump.

 

The numbers are normal. As far a bouncing back and forth..... I have a problem with mine when it gets cold here it sometimes doesn't like to read. I supposed things are freezing up in my samll FP lines. Does weather make any diffrence?

 

Personally as long as you have a fuel pressure gauge I wouldn't worry about it until pressures start dropping for a sustained time or your getting close to being out of warranty.

 

How much fuel was in your tank? If the tank is low, it gets more airated due to sloshing causing irratic readings. My guage does the same thing when the tank is low. Hope that helps, Marc

 

WAP. That's blasamy. Don't you dare talk like that.

MedicShawn. I don't know if the weather make's a differance or not. Today is the first time I noticed it. It's 40* here today.

BlueBull. I have less than 300 mile's left on my warranty.

Tweeter. I have about 3/8's of a tank. Would you consider that to be low enough to do what you say your's does.

UPDATE: I just went for a test drive after installing my aFe. I ran the crap out of it. When I pulled in the drive, I checked the gauge again and it seemed back to normal. Then I turned the light's on, and that gauge light didn't light up. I tapped the gauge and it came on. I would think that has to be a loose wire or bulb. That wouldn't have anything to do with the needle would it, since it's a mechanical gauge.

 

Bad, Anything above 1 psi is survivable. With a FASS or equivalent you get 15 psi all the time WOT to idle. I can remember just what you truck sounds like ...mine before I fixed the fuel shortage. Is your overhead correct for mileage. I noticed I was getting too good of mileage before my lift pump got too weak to tow heavy. ks

 

You scare me everytime you reply to one of my thread's. It alway's start's off with,,,"Bad". I alway's have to re-read the first sentence before I realize you mean me as Bad. That's ok though, don't stop replying.

So anyway. As far as the milage, I quit checking it by hand a long time ago. The overhead alway's seemed to be fairly close with figuring it by hand. I drive my friend nut's because I hit reset alot. He yell's at me and say's I'll never get my average mpg by hitting reset all the time. I yell back and say I don't want average, I want what it's getting right now on the highway. I just want to know if it's better or worse. That being said, I average about 22 on the highway at 65.

 

My stock LP was reading 8 at idle when I first installed the guage. It was only reading 6 psi before I installed the FASS. I'm sure it was on the way South when I unhooked it.
Take it to the dealer and tell them that last week it read 9psi and now it's at 6psi. Maybe they will give you a new pump......

 

I thought about doing that. But I remember reading somewhere, might have been on one of the tsb's on Geno's, that it said not to rely on aftermarket product's. Pull the pump and test. Or something to that effect. Knowing my luck, I'd have to pay the $100 detuctable, and they'd say your pump is fine.

 

There was a really cold day last year as I was driving to work on the highway. My fuel pressure was at 0 while cruising at 55 mph!! It really freaked me out and I worried all day if the truck was going to start or not. Well, it warmed up and all was back to normal. I use additives now.....

 

If UNDER 5 years old NO deductable on the ENGINE and FUEL system warranty.Its stated in the OWNERS manual.

 

Pressures are quite a bit lower on the common rail engines. Don't let the VP guys scare you.