Recently I have just purchased a W108 280SEL 3.5 (1971) from a friend of mine. The car has had quite a lot of new parts replaced, which is a good news to me. After a detail inspection, I have noticed a few problems and would like to invite members here with experiences dealing with W108.
1. Although the body is in resonably good condition for its age, yet I have found that the doors has a bit of bad rust spots, specially on the front right hand door. Does anyone here know if new replacement door still available and where I can order them?
2. The A/C pump did not switch on at the 1st place when I bought it due to lack of refrigerant, however after refilling, I have noticed the followings: a) the car when start at cold, the rev is about 1500RPM with choke on, then when A/C is on, it will drop to approx. 1430RPM. Once the engine warms up completely, the rev will drop to approx. 580-600RPM which doesn't allow the engine to run with A/C on, everytime when I rev the engine when the gear is in neutral and let go the gas padel, the engine just cut off due to sudden drop of engine revs. Is there any way I can do some adjustment somewhere? It seems that the engine is being controlled by electronics.
Any information regarding this car will be appreciated.
Hi ,new door skins ( or complete door frames) are readily available from mercedes Classic center in Irvine , Cal.. elieve me it's cheaper doing that than pissing around trying to fix rusty doors.
idle is set by placing the car in drive with aircon running and turning the air by pass screw situated in the front of the intake manifold.( white slotted plastic screw) . Before adjusting anything though.
Replace spark plugs and fuel filter ( under rear of car ) And air cleaner element.
Check igniton timing,check condition of plug leads ,cap,and rotor and replace if they are the slightest bit 'iffy'.
This should enable the car to idle properly.
The idle is static on these cars ( Djet injection ) theres no electronic idle control,that didn't come for another 20 years.
Thx for your info, luckily, the previous owner has just replaced the fuel distribution control unit (brand new) mounted on the firewall, as well as the injectors and the whole ignition distributor. So, there are less things to worry about.
For the idle, it is smooth but just that when I put it in parking gear, when the car is at working warm up temp, A/C on, almost every time when I rev the engine and let go the padel, the engine will stall. ... BUT, while the car is driving condition, this does not happen or it has not happened so far. I am just trying to eliminate this problem and make sure that the car doesn't stall while driving.
Get the engine nice and warm,open all the windows in the car and turn on the aircon. Get someone to apply the handbrake,then place the car in drive while you observe the engine running ( don't stand in front of the car!!!)
If it stalls,adjust the idle by turning the large plastic slotted screw ( airslide screw) on the front of the intake manifold 1 half turn anti clockwise.
Restart the engine and if it keeps stalling gently open the airslide screw until the engine idles at 750 RPM in gear with the aircon on .
When the car is cold this screw doesn't have any effect on idling because the Airslide is open and air is drawn through there.
Next step is to ensure that the throttle position switch is set correctly. USA cars are different to what I normally work on in that they fuel shut off devices for emmision control and there is a speed control relay which i am not familiar with that could cause your problem.
Last edited by mercmad6.3 : 09-03-2007 at 04:55 AM.
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