W202 - C180 - starting

You don't say if there's a difference between a cold start vs. a hot start.

I'd like to know the fuel pressure when car is parked on an incline and when parked on a level surface.

I'd also like to know if anyone checked the fuel pump relay (switch for fuel pump(s)). Has the motor ever died while driving? If YES, this becomes more of a suspect.

-->> T.G. Lambach I'd like to know the fuel pressure when car is parked on an incline and

Thanks T.G.

No difference between a hot or cold start. If I switch it off and then immediately restart then it's fine ... but cool morning or hot afternoon I still battle.

I did a pressure test about a month ago with the car parked on a sloped driveway, nose up. By morning the pressure was zero. Anthony ( MB trained mech ) did a pressure test on Thursday night while the car was parked on the level work bay. There was a slight drop but he said it was still within specs. He said he had no problems starting while it was on the level.

Don't think he checked the fuel pump relay but he removed the fuel sender units & cleaned them for me. Will follow up on that on Monday. I can hear the fuel pump "whizzing" for a few seconds each time I hold the key in the start position.

NOW .... for something interesting !! I've been parking nose down since last night and spent the day driving around town looking for parking bays with a fall .. all nose down. The car has started first time every time ... starter motor hardly has a chance to swing and she's purring.

Park nose up and it's a no-go. Tank is 3/4 full .. no leaks or petrol odours. Car runs beautifully otherwise and has never died on me. He also did a CO2 test .... think he said .5 @ 3000rpm.

Did I mention I put an aluminium non return valve near the outlet of the fuel filter .... thought the fuel was draining back into the tank due to a faulty non return valve in the pump.

After reading my post I think I'll put smaller tyres on the front and bigger ones on the rear ... may also raise the rear suspension ....( Tongue in cheek )

Reminds me of diesels with similar problems due to air seeping into their fuel supply.

I suggest you check the fuel pressure regulator (on the fuel rail). I suspect it is allowing air from the intake manifold to seep into the fuel rail when the motor is elevated so the fuel rail eventually fills with air. Since the fuel pumps run only about a second each time you try to start the motor it takes some tries to expel that air from the fuel rail before the motor can run.

I second the advice on checking the fuel pressure regulator. These are known to go bad on the w202.

On 2007$BG/(B12$B7n(B25$BF|(B, $B2 I second the advice on checking the fuel pressure regulator. These are

I have a second though which the fuel pump relay can also cause this kind of problem. A little green box sits next to the battery. While getting a helper to start the engine, you tap the top of the green box with the handle of a screw driver. If the car starts, 99.9% the fuel pump relay needs to be replaced.

Keith