mercuxio
Senior Member
- Joined
- May 14, 2011
- Messages
- 71
- Reaction score
- 6
- Location
- Malaysia
- Your Mercedes
- W211 E270CDI (D4) 03'
Car as above. A bit of background. Car left untouched for 2 years. Started to "restore" it few months back.
- Battery died, replaced with new
- Changed serpentine belt and tensioner pulley
- in-tank pump didn't work - took it out gave it some hammering - it started
- Battery drain - driver seat control module. Modded with relay to run on switched power
Car starts with no issues. Strong crank. However, idle dips and occasionally stalls (especially when putting in Drive or Reverse). Also stalls at idle sometimes. Problem gets worse when at operating temperature. Stalls when coming to a stop. No regular OBD error codes. Haven't had the chance to put in on the Star. It does feel like a fuel related issue. Revving above idle slightly causes hesitation and knocks (mild tap on pedal) followed by idle hunting. Otherwise its behaving normally. Drives with good power except stalling when coming to a stop.
What has been done.
- Bosch Specialist checked the injectors and HPFP
- Quantity control valved swapped tested
- Diesel filter replaced
- In-tank pump replaced as it only put out 3.8bars or pressure at idle (before the filter). New one at 4.5bars
- Replaced the fuel pressure regulator at the end of the rail (new or old they both causes the engine to cut out when I unplug the harness) I've seen posts indicating the engine should still run when unplugged??
- Unhooked the swirl flap motor to the connecting rod and moved the rod to full open position (unsure if the flaps are jammed inside the manifold)
- EGR has been deleted years ago. Therefore I ruled out this as a potential cause.
- Unplugged the injector harness 1 by 1 to try isolate a potential bad injector. The injectors are fairly new. Less thank 20k kms.
- De-catted upstream and downstream
- Changed the Crankshaft sensor
All the above yields no joy. Would like some opinions on this matter..Will have it on Star soon.
- is it air starvation? is air intake quantity vital at idle? Intake manifold clogged? Swirl flaps? No EGR operating though
- MAS problem?
- Injector codings? Never coded the injectors but never had problems when changed 20k kms ago.
-
- Battery died, replaced with new
- Changed serpentine belt and tensioner pulley
- in-tank pump didn't work - took it out gave it some hammering - it started
- Battery drain - driver seat control module. Modded with relay to run on switched power
Car starts with no issues. Strong crank. However, idle dips and occasionally stalls (especially when putting in Drive or Reverse). Also stalls at idle sometimes. Problem gets worse when at operating temperature. Stalls when coming to a stop. No regular OBD error codes. Haven't had the chance to put in on the Star. It does feel like a fuel related issue. Revving above idle slightly causes hesitation and knocks (mild tap on pedal) followed by idle hunting. Otherwise its behaving normally. Drives with good power except stalling when coming to a stop.
What has been done.
- Bosch Specialist checked the injectors and HPFP
- Quantity control valved swapped tested
- Diesel filter replaced
- In-tank pump replaced as it only put out 3.8bars or pressure at idle (before the filter). New one at 4.5bars
- Replaced the fuel pressure regulator at the end of the rail (new or old they both causes the engine to cut out when I unplug the harness) I've seen posts indicating the engine should still run when unplugged??
- Unhooked the swirl flap motor to the connecting rod and moved the rod to full open position (unsure if the flaps are jammed inside the manifold)
- EGR has been deleted years ago. Therefore I ruled out this as a potential cause.
- Unplugged the injector harness 1 by 1 to try isolate a potential bad injector. The injectors are fairly new. Less thank 20k kms.
- De-catted upstream and downstream
- Changed the Crankshaft sensor
All the above yields no joy. Would like some opinions on this matter..Will have it on Star soon.
- is it air starvation? is air intake quantity vital at idle? Intake manifold clogged? Swirl flaps? No EGR operating though
- MAS problem?
- Injector codings? Never coded the injectors but never had problems when changed 20k kms ago.
-
