Rawze.com: Rawze's ISX Technical Discussion and more

Here’s the fault that came up.The fuel one I was able to erase but once it went through wanting to shut down after starting up.

Will the lift pump cause the low fuel pressure at start up?

(06-14-2021 )Redland1 Wrote: [ -> ]Will the lift pump cause the low fuel pressure at start up?

If it is going bad it will... yes. .. so will that screen located right at at the intake of the electric lift pump on older 870's too... hence Why I asked you 2 times already if you had removed that screen.

(06-14-2021 )Rawze Wrote: [ -> ]

(06-14-2021 )Redland1 Wrote: [ -> ]Will the lift pump cause the low fuel pressure at start up?

If it is going bad it will... yes. .. so will that screen located right at at the intake of the electric lift pump on older 870's too... hence Why I asked you 2 times already if you had removed that screen.

I missed the part where you asked about the screen.I’m going to go look at it now.Once I unhook that line will it dump a bunch of fuel?

There wasn’t a screen filter on the lift pump inlet.Also looked at rail pressure before cranking and it was 17psi and 270 while idling for 15 minutes and the lowest it dropped was 258.

(06-15-2021 )Redland1 Wrote: [ -> ]... 270 while idling for 15 minutes and the lowest it dropped was 258.

that is normal pressures.

(06-15-2021 )Rawze Wrote: [ -> ]

(06-15-2021 )Redland1 Wrote: [ -> ]... 270 while idling for 15 minutes and the lowest it dropped was 258.

that is normal pressures.

Anything else that can be causing that low fuel pressure code to come one intermittently?

Have you checked your main gear pump? We have had reports on here where the pump shaft was sheered off but was still able to produce adequate fuel pressures to run the truck.

Also crappy/clogged fuel filters cause this symptom.

Fuel filters have a weeks worth of fuel through them.