Advice needed o Misfire and Idle Problems [W202 C280]
 

Dear All,

I have a problem with my 1996 C280.

When I am driving a car it seems to be OK, ride is smooth but it does not feel like its got 197bhp, not as flamboyant nor aggressive as you would think, I have only bought it recently but I could say something is missing/wrong.

The car drives ok but I have noticed several issues:
1. The car vibrates on the idle, like it would be misfiring
2. Car started to idle very high @1400rpm, it used to be 700-800 and now only from a time to time it goes down to that figure otherwise it stays at 1400 mark, this appeared after cleaning MAF and thottle body
3. Car uses quite a lot of fuel but I realize that it is very petrol hungry especially in town cycles :)

The actions I have taken so far:
1. Changed oil, all filters
2. Changed spark plugs
3. Changed HT Leads and Inition Coils (all)
4. Checked wiring loom (seems to be ok)
5. Cleaned MAF sensor
6. Cleaned throttle body

From extensive research online I can sat that one of the following can be causing the issue:
- Resonance valve
- Idle Control Valve
- Crankshaft Position Sensor
- Camshaft Position Sensor
- Mass Air Flow Sensor

From your experience what would you recommend for me to do next? I need to add that I cannot locate the OBD2 socket :nix: (Left Hand Drive - UK car), so I could not read the codes.

Many thanks for all your help in advance.