270 ML engine cuts out on kickdown
02-02-2010, 04:58 PM
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ML 270 CDI
270 ML engine cuts out on kickdown
ML 270 CDI - Car runs perfectly and normal kickdown OK but if you give it a large kickdown eg. when overtaking, engine cuts out competely which is a bit scary when you have no power steering. Injector seals have all been replaced and diagnostics say "Rail Pressure Monitoring" as a fault code.
Not sure what it could be. Help need please...
Not sure what it could be. Help need please...
02-03-2010, 02:03 AM
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190D 2.5 (x2), 190E 2.6, W202 C240,W202 C43 (C55), W210 E55, W212 E250CDI
That's usually a very good indication that a injector has failed internally. Basicly the is a large enough internal leak in a injector that the ECU detects it as a fuel leak (although it's an internal leak in this case) and shuts the engine down as self protection.
You need to get your injectors tested for leakage at higher fuel pressure than idle (test is done at 800bar, idle is 280bar). This is easily done by someone with a MB diagnostic machine.
Time to find you local dealer or local independant MB specalist.
You need to get your injectors tested for leakage at higher fuel pressure than idle (test is done at 800bar, idle is 280bar). This is easily done by someone with a MB diagnostic machine.
Time to find you local dealer or local independant MB specalist.
02-03-2010, 03:52 AM
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Thanks very much for your diagnosis. Sounds very plausable that there is an internal leak. Will book in with MB specialist ASAP for a check and will let you know outcome.
By the way, can injector be repaired or would a replacement be needed should this be the problem?
Thanks again for prompt reply.
By the way, can injector be repaired or would a replacement be needed should this be the problem?
Thanks again for prompt reply.
02-03-2010, 05:07 AM
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190D 2.5 (x2), 190E 2.6, W202 C240,W202 C43 (C55), W210 E55, W212 E250CDI
Technically they can be repaired but the tools and parts are only just starting to reach the market place so it would be very hard to find someone who could do this near you. Replacement is currently the best and easist option.
02-03-2010, 07:09 AM
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Thanks again,
My MB specialist says he cannot do a live diagnosis.Have today given the car another test run. From standing start car revs perfectly well upto 5000 revs. On normal kickdown also car drives well into high revs.
It is only when driving at normal revs and you want to give it a hard peddle to the metal kickdown that engine cuts out. And it cuts out at the 3000 rev mark if this helps.
Do you think it is still a failed injector?
MB Specialist says could be MAF sensor problem?? (Was replaced 6 months ago)
I am thinking more on your lines...
Do you advise to go to MB Dealer for diagnosis?
My MB specialist says he cannot do a live diagnosis.Have today given the car another test run. From standing start car revs perfectly well upto 5000 revs. On normal kickdown also car drives well into high revs.It is only when driving at normal revs and you want to give it a hard peddle to the metal kickdown that engine cuts out. And it cuts out at the 3000 rev mark if this helps.
Do you think it is still a failed injector?
MB Specialist says could be MAF sensor problem?? (Was replaced 6 months ago)
I am thinking more on your lines...
Do you advise to go to MB Dealer for diagnosis?
Last edited by eviebo; 02-03-2010 at 07:17 AM.
02-04-2010, 01:54 AM
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190D 2.5 (x2), 190E 2.6, W202 C240,W202 C43 (C55), W210 E55, W212 E250CDI
It's definately an injector problem. It took me a while to work it out the first time I saw it. The common failure is when they leak all the time so the engine won't or is hard to start. The shut down is very unusual, hence why it took me a while to diagnose the first one I saw.
Basicly fuel pressure is adjusted not by rpm alone but also by load which is why the fault occurs at high rpm and high load and not just when revving.
A MAF failure gives low power all the time, engine light (if enabled) and limited RPM. It won't cause the engine to stall.
You need a set of injector test tubes as a minimum to diagnose which injector is the faulty one. basicly you attach the tubes to the leak off connector for each injector and run a automated injector test (if you have star diagnosis) or just put it in gear and load up engine. You will see that one or possible 2 tubes will fill up really quickly when compaired to the others. this is your faulty injector.
When it is a no start or hard starting then you will be able to see the faulty injector just by cranking it, it would fill up really fast just during crank.
Basicly fuel pressure is adjusted not by rpm alone but also by load which is why the fault occurs at high rpm and high load and not just when revving.
A MAF failure gives low power all the time, engine light (if enabled) and limited RPM. It won't cause the engine to stall.
You need a set of injector test tubes as a minimum to diagnose which injector is the faulty one. basicly you attach the tubes to the leak off connector for each injector and run a automated injector test (if you have star diagnosis) or just put it in gear and load up engine. You will see that one or possible 2 tubes will fill up really quickly when compaired to the others. this is your faulty injector.
When it is a no start or hard starting then you will be able to see the faulty injector just by cranking it, it would fill up really fast just during crank.
