High Pressure intermitent drops on CDTI

ex250 · 15th February 2020, 08:04

Hi guys, I'm experiencing some drops on the High pressure side each second more or less.

I first noted that on road, without accelerating, the car seemed to slightly oscillate on power, like I was stepping on and releasing the throttle slightly and not mantaining the speed.

Connected the laptop to see if there was any fault and nothing except the glow plug one, nothing related.

I make the reading for the low pressure pump and was consistent on 3.6 bar, but on the high side, there are drops of arround 50 bar or more each second at 800 rpm and more noticeable at upper revs.

I have had bypassed the fuel filter with the same results, so it's not from the filter or filter case.

Next suspect could be the fuel pressure regulator on the HP pump?

Also consumption increased slightly. This issue is active with full and near empty tank

Open to more ideas...

15th February 2020, 08:04	#1
ex250 Regular poster MG ZT CDTi Join Date: Jul 2010 Location: Spain Posts: 39 Thanks: 1 Thanked 0 Times in 0 Posts	High Pressure intermitent drops on CDTI Hi guys, I'm experiencing some drops on the High pressure side each second more or less. I first noted that on road, without accelerating, the car seemed to slightly oscillate on power, like I was stepping on and releasing the throttle slightly and not mantaining the speed. Connected the laptop to see if there was any fault and nothing except the glow plug one, nothing related. I make the reading for the low pressure pump and was consistent on 3.6 bar, but on the high side, there are drops of arround 50 bar or more each second at 800 rpm and more noticeable at upper revs. I have had bypassed the fuel filter with the same results, so it's not from the filter or filter case. Next suspect could be the fuel pressure regulator on the HP pump? Also consumption increased slightly. This issue is active with full and near empty tank Open to more ideas...