C220 CDI - Loss Of Power

[idawson]

Hi,
I've a C220 CDI which in the past couple of days has started to behave strangely. Normally the car drives fine but if stopped at a light & you accelerate there can be a lull before the power kicks in, also when on different occasions it has started to restrict the RPM on the car, it will only rev out to 3000 through the gears - and yet sometimes it will allow full revs.

The car is a 2001 with 123k on the clock

Thanks

 

[television]

Hi,
I've a C220 CDI which in the past couple of days has started to behave strangely. Normally the car drives fine but if stopped at a light & you accelerate there can be a lull before the power kicks in, also when on different occasions it has started to restrict the RPM on the car, it will only rev out to 3000 through the gears - and yet sometimes it will allow full revs.

The car is a 2001 with 123k on the clock

Thanks

This should be the MAF filter needs replacement, cheaper from Bosch.

 

[idawson]

Thanks for the quick reply. Just found the Cleaning guidelines - would it be worthwhile doing that first?
Thanks

 

[television]

Thanks for the quick reply. Just found the Cleaning guidelines - would it be worthwhile doing that first?
Thanks

By all means try it, as you have nothing to lose,you can also check by unplugging it and giving the car a run

 

[eric242340]

By all means try it, as you have nothing to lose,you can also check by unplugging it and giving the car a run

Certainly with petrol Benz, unplug the MAF sensor and drive it will give you an answer as the ECU (engine control unit) has back-up varient data in case of failure. But, Malcolm, (and this may suprise you again) we have no CDI here, so I dont know if the same programme exists with CDI. So, for me, please disconnect the MAF sensor and give us your results. This would be an interesting experiment. Is CDI different to Petrol on the MAF sensor basis, I think not but I wait to hear about his test.

 

[television]

Certainly with petrol Benz, unplug the MAF sensor and drive it will give you an answer as the ECU (engine control unit) has back-up varient data in case of failure. But, Malcolm, (and this may suprise you again) we have no CDI here, so I dont know if the same programme exists with CDI. So, for me, please disconnect the MAF sensor and give us your results. This would be an interesting experiment. Is CDI different to Petrol on the MAF sensor basis, I think not but I wait to hear about his test.

This works on the same principle and has been done on CDI engines

 

[eric242340]

This works on the same principle and has been done on CDI engines

Thanks for that Malcom, like I said no CDI here so comparrison is difficult. But I would expect it works on the same principle.

 

[television]

Thanks for that Malcom, like I said no CDI here so comparrison is difficult. But I would expect it works on the same principle.

Diesels are not my best point eric, but after 2 teach in sessions at seminars I have picked up a bit, but not the same as having done it, so I do not go near them much

 

[egrid1]

Sorry to revive such an old thread, but I may have an answer to the question posed...

Certainly with petrol Benz, unplug the MAF sensor and drive it will give you an answer as the ECU (engine control unit) has back-up varient data in case of failure. But, Malcolm, (and this may suprise you again) we have no CDI here, so I dont know if the same programme exists with CDI. So, for me, please disconnect the MAF sensor and give us your results. This would be an interesting experiment. Is CDI different to Petrol on the MAF sensor basis, I think not but I wait to hear about his test.

My 2001 E220 CDi had sudden onset of problems with rough idle, some smoke and slow pick up when moving away. I have unplugged the MAF and the problems seem to have gone. However the car now seems to be in limp home mode as it will not go above 3000 revs in drive or go over about 45. It will if I knock it down the gears manually, and picks up the speed fine.

It suggests to me that the MAF sensor, was sending an incorrect signal, removing it appears to suggest that the CDi ECU also has a standard map for when the MAF is not sending a signal, but will also put the car into limp mode.

I guess my next step is to buy a Bosch MAF.

 

[duncanh]

I don't think you want a Bosch MAF

I guess my next step is to buy a Bosch MAF

I believe that cdi-engined cars use Pierbrg MAFs, not Bosch.

Your best bet is Eurocarparts, they sell genuine Pierburg ones, much cheaper than your Merc dealer.