C63 fuel pump concern
#1
Senior Member
Thread Starter
C63 fuel pump concern
Hello everyone I have a question about fuel pump! I test the fuel pump pressure and once I turn the key ON fuel pressure shows 70psi once I start the car goes down to 60psi once I keep RPM's at 3-4K PSI drops to 49-51 PSI I got the fuel pump already but don't wanna install it yet if it's going to be something else since I can't return it once I install it and these are the cods I have P228f code p0101 p010b p420 p430, would like to hear your input.
Thank you!
Thank you!
#2
Junior Member
I'm not familiar with the fuel system in the C63 but in most systems it's entirely normal for fuel pressure to drop when you start the car (some cars do run constant pressure systems though...). The pressure regulator maintains a constant pressure relative to the intake manifold so when you have a vacuum in the manifold (engine running at idle for example) the fuel pressure drops accordingly.
If however the pressure is dropping as much as you say (70-49= 21psi) that would indicate the fuel pump is faulty as fuel pressure is dropping by more than one atmosphere.
If however the pressure is dropping as much as you say (70-49= 21psi) that would indicate the fuel pump is faulty as fuel pressure is dropping by more than one atmosphere.
#3
Super Member
Are you checking it with the car stationary or going down the road?
I assume you are checking on the fuel injector rail, is at the the end of the rail? ( I have never looked)
To be fair, 50 psi of fuel pressure is still a lot.
Is the pressure regulator on these cars electric or vacuum operated
I assume you are checking on the fuel injector rail, is at the the end of the rail? ( I have never looked)
To be fair, 50 psi of fuel pressure is still a lot.
Is the pressure regulator on these cars electric or vacuum operated
#4
Super Member
Do any of those codes represent low fuel pressure?
Sorry, I don't have a code dictionary handy
Edit... Just read where the fuel pressure is controlled by a module that varies the voltage to the pumps to make the pressure go up and down based on demand
Sorry, I don't have a code dictionary handy
Edit... Just read where the fuel pressure is controlled by a module that varies the voltage to the pumps to make the pressure go up and down based on demand
Last edited by QWKSNKE; 11-19-2015 at 08:26 PM.
#5
MBWorld Fanatic!
Hello everyone I have a question about fuel pump! I test the fuel pump pressure and once I turn the key ON fuel pressure shows 70psi once I start the car goes down to 60psi once I keep RPM's at 3-4K PSI drops to 49-51 PSI I got the fuel pump already but don't wanna install it yet if it's going to be something else since I can't return it once I install it and these are the cods I have P228f code p0101 p010b p420 p430, would like to hear your input.
Thank you!
Thank you!
#6
MBWorld Fanatic!
What are the code definitions?
#7
if you have a tune, thats why..alotta you guys run your tune all year round..BAD idea, you all need a winter tune..every year within the same week my car acts weird as hell and feels like it'll blow up anytime, i switch the tune to my winter tune and runs fine..its because the AFR is all whack this time of year
if your fuel pumps are shot you'd barely be able to drive the car, it'll shake, rattle, barely idle. I've been through 2 sets of fuel pumps and it's the same every time
if your fuel pumps are shot you'd barely be able to drive the car, it'll shake, rattle, barely idle. I've been through 2 sets of fuel pumps and it's the same every time