please, can anyone help on this

[mr rosher]

thanks guys for all the help in the past, much appreciated, my e280 19993 is now running 98.9 %, but she still idles slightly to low when in D - R, in P _ N
idles at 750 rpm fine, as soon as she goes in D _ R the rpm drops to 550 - 600 and she starts to hesitates, this is the work i've done over the last year,

head, skimmed, decoked, new valves, seals, pressure tested,
new air mass,
new coolant temp sender,
new injecter seals,
head gasket,
new o v p relay,
rebuilt wiring loome,
inlet cam shaft renewed as mine snaped on head refit,
charcoal canister checked by local dealer,
trottle body changed, and cleaned,
new gear box oil a filter
egr valve cleaned and checked,
and eventually complete engine rebuild, as the bigends went ? when she overheated,
cost so far £1,890, most of the work has been done by myself,
she's been back on the road in the last 2 weeks and still running in, so far done 800 miles, i've been told of a switch or relay that increases the rpm by 50 rpm when in drive, or may be the pressure control cable is set wrong, i've cleaned all the relays, and fuses, but can't find the relay or switch that changes the idle when in drive, phoned the local mercedes dealers and asked but won't say ?? i've also been told that when key is turned on, there should be 2.5 -5. volts on one of the pins for the air mass plug, mine has nothing,
any help would be much appreciated as i am at a loss ,

many thanks rod

 

[kth286]

In terms of the revs when in D compared to the revs when in N for example it is very normal.

Thers is a load when in D and R and there is no compensation on my car to keep the revs at the high of 700/750. when in these positions.

Your only problem is the slight misfire.

I notice the Lambda prove has not been changed and it is a wear item on that generation of cars and therefore feed back will be sluggish and so the car might want to stall.

Also I would suspect a bunged up charcoal canister which you say has been checked by a technician.

How can he do that ? as they are pretty well sealed.

If you have no record of the canister being changed, and your car has done over 70,000 miles, then change it. Make sure you know the order of the pipes connections. This is a Mercedes maintenance item on the service list for your car

 

[mr rosher]

In terms of the revs when in D compared to the revs when in N for example it is very normal.

Thers is a load when in D and R and there is no compensation on my car to keep the revs at the high of 700/750. when in these positions.

Your only problem is the slight misfire.

I notice the Lambda prove has not been changed and it is a wear item on that generation of cars and therefore feed back will be sluggish and so the car might want to stall.

Also I would suspect a bunged up charcoal canister which you say has been checked by a technician.

How can he do that ? as they are pretty well sealed.

If you have no record of the canister being changed, and your car has done over 70,000 miles, then change it. Make sure you know the order of the pipes connections. This is a Mercedes maintenance item on the service list for your car

hi kth 286, sorry ,?? but i've changed so many things in the last 12 months, the lambda sensor has been changed, but i forgot to say, i've been reading other threads about the charcoal canister and they all seem to point to the same problems as im having, apart from the idle problem she drives lovely and so smooth, so i guess i will order one tomorrow from local dealer and see how it goes, any idea on price, and can i get one from some where else then the main dealers,

thanks for your help, will keep you posted on results,
rod,

 

[kth286]

Charcoal canister £53 on the Inchcape Mercedes site today inclusive of VAT and with 10% off.

Can be posted to you next day for small cost.

Give VIN to the parts man. Merc only is best.