W203 c200 CDi P0088 Fuel pressure high fault

[paul3944]

After some advice over the below fault.

Over the Xmas period the CEL came on and went into limp mode however the car was running perfectly prior. The car has recently been serviced and the fuel filter replaced (Mann). Indy reported high fuel pressure and suggested changing the fuel filter.

Over the weekend the fault has appeared again and gone into limp mode. I have checked the injectors visually and there is no sign off leakage externally or black death around the injectors.

There are no leaks from the HPFP and all lines are intact. Checked all intercooler hoses and all appears to be in order. The engine doesn't run rough or cut out and no smoke visible.

This car is turning quickly into a money pit, I simply cannot change all the fuel systems components one by one until the fault goes away as suggested by the Indy.

Any pointers would be most welcome
Paul

 

[BlackC55]

You need it on a Star diag machine to get to the bottom of this. There are some guided tests for this kind of code.

 

[Wayne.clk]

I had the same problem with my clk,
No one could ever get to the bottom of it,
It went on star that said fuel monitoring issue so changed both fuel regulators (one on pump one on rail) no change, changed the fuel pressure sensor still no change
I had leak off test done on injectors all fine, fuel pressure checked coming out of the pump well within tolerance, fuel pressure checked on rail no problems there either and as u have done checked all pipes and electrical connections but yet still no faults I even had my indie come out on a road test with the star plugged in and he was checking everything possible all well within tolerance Infact he said the engine/turbo/fuel management was perfect best he has seen!

Then one day all was fine light never came back on and been fine ever since
Strange
Hope u get to the bottom of it and if u do pls report back on here would be interesting to see your out come

 

[paul3944]

Many thanks for the replies.

I'll get it connected upto Star again this week, is it possible to get a print out once the diagnostics is completed?

Kind Regards,
Paul

 

[BlackC55]

Many thanks for the replies. I'll get it connected upto Star again this week, is it possible to get a print out once the diagnostics is completed? Kind Regards, Paul

Yes

 

[paul3944]

This was fixed in the end and for reference was the fuel quantity valve located on the high pressure fuel pump.

Regards
Paul