engine jerky in summer, ok in winter

[anyweb]

yup, that's about it, when i'm driving below 70 km/ph in summer (noticed it a month ago or so when temps rose above 15c) the car is jerky (best I can describe it, almost like it wants to cut out but doesnt) in low gears but fine on a motorway crusing at 120km/ph.

however, in the winter I do not have this problem at all, its smooth in low speed and high speed, I've replaced the viscous fan coupling and the temp does rise but not too high so what could be causing this ? the maf ?

 

[mattkh]

yup, that's about it, when i'm driving below 70 km/ph in summer (noticed it a month ago or so when temps rose above 15c) the car is jerky (best I can describe it, almost like it wants to cut out but doesnt) in low gears but fine on a motorway crusing at 120km/ph. so what could be causing this ? the maf ?

Hi
Do you know which temperature sender is used by the ECU

 

[anyweb]

absolutely no idea, how can I find out and where would it be located ? its a merc c220/1995

cheers

anyweb

 

[Daeths]

yup, that's about it, when i'm driving below 70 km/ph in summer (noticed it a month ago or so when temps rose above 15c) the car is jerky (best I can describe it, almost like it wants to cut out but doesnt) in low gears but fine on a motorway crusing at 120km/ph.

however, in the winter I do not have this problem at all, its smooth in low speed and high speed, I've replaced the viscous fan coupling and the temp does rise but not too high so what could be causing this ? the maf ?

If you wait a week, Malcolm may be able to help !

lol

Adam

 

[C220GJS]

As your problem seems to be caused by the change in ambient temperature I would think the intake air temperature sensor is the most likely culprit. It is located in the air intake trunking just before the throttle/idle control valve and is just clipped in place , check it has not become contaminated by oil or the element has not broken, be careful it is fragile .

 

[anyweb]

got a photo of this location C220GJS ?

cheers

anyweb

 

[C220GJS]

To check the sensor ,remove it and check the resistance using a meter.
Resistance at 10c ambient 9186-10153 ohm.
" " 20c " 5757-6363 ohm.
" " 30c " 3705-4095 ohm.
Hope this helps ,it seems the likeliest culprit to me.

 

[C220GJS]

got a photo of this location C220GJS ?

cheers

anyweb

It's in the black plastic intake trunking which crosses over the camcover , as I said it is just before the trunking connects to the throttle valve , see here ;http://www.detali.ru/cat/oem_mb2.as...GM=717.417&CT=M&cat=19K&SID=15&SGR=120&SGN=05 .