Engine/Transmission (1998.5 - 2002) Is my FASS going south ?

[Tractorat]

I had a FASS installed last august. Only have about 5k miles on the truck since then.
This afternoon I was going down a shallow hill and made a hard stop. Not tire screeching, but enough to spill a cup of coffee. The low fuel pressure led came on and stayed on for a couple of seconds. I found I could do it every time. At first I wondered if maybe I was low on fuel, and maybe that was causing the low fuel pressure. But my gauge said I have a 3rd of a tank. And from the number of miles Ive driven since I filled up, I should have a good 10 or 12 gal of fuel. BTW, I do normally fill up well before it gets even that low.

I tried the stop on a level road and going up hill and the led would not come on. But when I was going down hill again, I could turn in on with a hard stop.

I clicked the key 3 times and no codes. Also, when I first had the FASS installed, if I just bumped the starter, it would turn the LED off and it would stay off. Now when I just bump the starter it doesnt go out at all.

 

[SnoKing]

Sounds a little normal depending of the hill! SNOKING

 

[Tractorat]

Never did it before. And bumping the started used to turn the FP LED off.

 

[SnoKing]

Your pickup tube might be rusted out. How many miles. Get a gauge! Idiot lights are for Id.....'s. Snoking

 

[Tractorat]

110k miles

 

[JR]

Do you have hard starts after the truck sits for a while? (Longer than normal crank times?)

In my opinion the low pressure light is not enough, especially if you work the truck hard. Most lights dont come on until 3-5 psi and that is not enough flow through the VP.

Does the FASS have a return line dumping back to the tank? I'm not familiar with them but Air Dogs use a ball and spring that acts as a check and from time to time they can stick open causing lower than normal fuel pressure.
Again, this is where fuel pressure gauges pay for themselves. They are a great trouble shooting tool when things start acting up.

 

[Tractorat]

Do you have hard starts after the truck sits for a while? (Longer than normal crank times?)

Nope. But even when the first LP and then IP went out at about 50k, and when the 2nd LP went out at about 103k, it has always started just like it was brand new.

 

[JR]

You'll have to dig up a pressure gauge to verify lift pump is working. If you don't want to put an actual gauge in the truck, you can buy a cheapo manual gauge and temporarily install it in place of the fuel pressure light. It will get you a ball park idea, but not as good as being able to watch the pressure while you drive and exercise the engine.

 

[jeepit]

My draw straw acted like this cuz I cut it too short. I'm thinking it's your pick tube. And fuel float is not working properly.

 

[SnoKing]

Without a fuel pressure gauge, he will never know!!! SNOKING