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HI, I created new thread because I did try to search for all around for a while can couldn't find what I need. So I Hope someone can help.
The problem is: my car popped CEL with P228F: "pressure at fuel line excess". I searched this forum and some one said that just use fuel injector cleaner or Techron bottle or any additives and it will work. But it doesn't work for me and I did check fuel line pressure with "fuel pressure test kit" result:
Prime: 10psi
idle: ~52psi
rev to 3000 rpm in 'P': ~52 psi
rev to 4000-5000 rpm in driving: ~ 62 psi
turn off engine couple minutes later: ~ 70 psi
That is the result from my diagnose so any one has idea: is it normal or what reasons for those please share idea.
Thanks
Update:
Procedure of diagnose fuel rail pressure.
I hook up the 'fuel pressure test kit' gauge to the windshield so I can monitor the pressure during my drive and reset check engine light. and drive to work.
Result:
Idle or over drive: around 52 psi
WOT or hard acceleration: gain to less than 60 psi
turn off engine: pressure keep increase from 52 psi
start engine and drive for less than 1 mile: 'check engine light' on
So my question is:
Check engine light turn on because of "turn off engine and pressure keep increase"? or "fuel pressure not constant during driving"?
Thanks
Fuel rail should maintain pressure after key off; on my car it will hold pressure (gradually decreasing) for well over an hour to two. Fuel pressure is controlled by the two each fuel pumps which, in turn, are controlled by a Pulse-Width-Modulated signal from the motor electronics; i.e. lower pressure at idle since pumps are not running full speed, higher pressure at WOT with pumps running full speed. The E55 uses on/off relay(s) while the E63 uses PWM controllers located inside the trunk on the passenger side rear wheel well. I link to a post below where the technical documentation shows fuel rail pressure should be 58 psi to 80 psi depending upon load.
This may be time for fuel filter/regulator as the symptoms are similar (but not identical) to an E55 with a fuel filter that is clogged/clogging. Please post your solution once you resolve the issue.
I did research about the fuel system and our engine used returnless fuel system, so fuel rail pressure will send value to PCM to control fuel pump speed. so I don't know that the fuel pressure sensor diaphragm is dirty to make the movement of it kind of lag so the pressure adjustment is slow and higher.
I did remove the fuel rail sensor last night, and there is a hole for fuel come in to pressure on the diaphragm.
and I try to clean it with a carburator cleaning kit and feel that the diaphragm is like sticky with something inside, it not smooth movement. and after I clean it, put it back and the car idle is really smooth and sensitive acceleration but for only a few miles and back to normal. So I decided to order fuel pressure sensor. so wait for the result.
So for our E63, there are 2 fuel pumps on both sides?
Two fuel pumps on passenger side; filter/regulator on driver's side. Note your fuel pressure is lower than that called for in the technical documentation. If you can put an ammeter on the pumps, if it is 20 amps or greater at idle, you need a fuel filter. I'd have to search for the reference again but it's out there. Remember that low fuel pressure means higher air/fuel ratios, potential detonation, and potential engine damage/destruction.
It's in here somewhere; you'll have to search but I've seen it as the photo of the PWM controllers for the E63 was mistakenly placed in the E55 section. https://workshop-manuals.com/mercedesbenz/
Two fuel pumps on passenger side; filter/regulator on driver's side. Note your fuel pressure is lower than that called for in the technical documentation. If you can put an ammeter on the pumps, if it is 20 amps or greater at idle, you need a fuel filter. I'd have to search for the reference again but it's out there. Remember that low fuel pressure means higher air/fuel ratios, potential detonation, and potential engine damage/destruction.
It's in here somewhere; you'll have to search but I've seen it as the photo of the PWM controllers for the E63 was mistakenly placed in the E55 section. https://workshop-manuals.com/mercedesbenz/
my pump works great, fuel pressure at rail is high, its normal from idle to 3000 rpm, but hard acceleration or WOT, pressure up to 62psi but later it will back to 52 psi in few second! Its not constant stay around 52 psi! May be signal from Rail sensor is lag or whatever. Just wait for my fuel rail sensor arrive
my pump works great, fuel pressure at rail is high, its normal from idle to 3000 rpm, but hard acceleration or WOT, pressure up to 62psi but later it will back to 52 psi in few second! Its not constant stay around 52 psi! May be signal from Rail sensor is lag or whatever. Just wait for my fuel rail sensor arrive
Did you you ever find a solution to this problem? I'm experiencing similar problems
01-20-2019, 03:25 PM
