Tweet
I have been having misfire/stuttering issues for some time now that were very intermittent but seem to be getting worse. I went on a road trip a few weeks ago and a few times had what felt like a fuel cut while doing 120 on the highway: driving along at constant speed, give it some gas to go up a hill, speed up a little and then nothing, down shift and still nothing, lose some speed, and then it recovered and accelerated fine.
It has thrown random/multiple cylinder misfire codes and each cylinder misfire codes, and a couple of times:
Fuel Rail/System Pressure P0087 - 002 - Too Low - Intermittent
I have replaced all of the ignition coils, spark plugs, cam follower, checked electrical grounds, diverter valve, cam follower and high pressure fuel pump shaft, etc. The fuel filter was replaced a couple of years ago so it shouldn't be that.
Today I ran vag-com logs over two 1/2 hour trips and found the low pressure fuel pump sits at 4.5 bar and 50% electrical load all the time regardless of engine load. Pressure dipped to 4.2 bar once and hit 5 a couple of times, but other than that hovered right around 4.5 regardless of pressure in the high pressure rail (ranged from 70 - 110 bar). The service manual says output from the low pressure pump should be 3-7 bar, but I would expect some movement in that range right?
So I'm thinking the low pressure pump isn't putting out enough for the high pressure pump to keep up with but want to confirm that this behaviour is in fact weird. Thoughts?
It has thrown random/multiple cylinder misfire codes and each cylinder misfire codes, and a couple of times:
Fuel Rail/System Pressure P0087 - 002 - Too Low - Intermittent
I have replaced all of the ignition coils, spark plugs, cam follower, checked electrical grounds, diverter valve, cam follower and high pressure fuel pump shaft, etc. The fuel filter was replaced a couple of years ago so it shouldn't be that.
Today I ran vag-com logs over two 1/2 hour trips and found the low pressure fuel pump sits at 4.5 bar and 50% electrical load all the time regardless of engine load. Pressure dipped to 4.2 bar once and hit 5 a couple of times, but other than that hovered right around 4.5 regardless of pressure in the high pressure rail (ranged from 70 - 110 bar). The service manual says output from the low pressure pump should be 3-7 bar, but I would expect some movement in that range right?
So I'm thinking the low pressure pump isn't putting out enough for the high pressure pump to keep up with but want to confirm that this behaviour is in fact weird. Thoughts?
Comment