Fuel Pump Issue

Mud digger · Sep 1, 2013

When I turn my key on to let the glow plugs cycle I can hear my fuel pump but instead of the constant buzz from it, it cuts in and out. I can also see this on my fuel pressure gauge. It doesn't do it all the time, mainly just when started first thing in the morning. It continues to cut in and out when I begin to drive it but levels out after a few minutes. I have a stock pump. Anybody else ever have this issue? Thanks in advance

loboost · Sep 1, 2013

Mud digger said:
When I turn my key on to let the glow plugs cycle I can hear my fuel pump but instead of the constant buzz from it, it cuts in and out. I can also see this on my fuel pressure gauge. It doesn't do it all the time, mainly just when started first thing in the morning. It continues to cut in and out when I begin to drive it but levels out after a few minutes. I have a stock pump. Anybody else ever have this issue? Thanks in advance

That's what mine did right before it does completely. What's fuel psi do during this?

Mud digger · Sep 1, 2013

loboost said:
That's what mine did right before it does completely. What's fuel psi do during this?

It jumps from 60 to around 52 initially, but gets better as it runs. Eventually it levels out at 60.

Mud digger · Sep 2, 2013

I went out this morning and before starting I drained my fuel/water separator. I started the truck and no bouncing of the fuel pressure and no cutting out of the pump. The problem is very intermittent. One thing I did notice is that immediately after starting the FP was 55 and after idling for a minute or so it made it's way up to 60 and leveled out. WTF is going on? Is my pump starting to get weak? It's the original pump and has 135k miles on it.

Mud digger · Sep 14, 2013

Anyone have a clue what could be causing this? I can hear the pump cutting out when I cycle the key, and I can see my FP jump up and down. FP levels out after a few minutes of driving.

Atsah · Sep 14, 2013

Sure sounds to me like the pump is on it's way out.. If it were me, I would change it out before your injectors let you know it's a bad idea to not have a good, constant PSI... The Fuel Pressure Regulator might also be causing this..

Maybe install the updated FPR kit first since it's only about $75.00 and it should be done anyway and see if that takes care of it, if not change the pump..