itchey
Active Member
- Joined
- Mar 6, 2012
- Messages
- 29
- Reaction score
- 0
- Location
- Northumberland
- Your Mercedes
- 1999 Mercedes 250TD Sport Auto.
Could someone out there advise me on my thoughts of why air is getting in the fuel system.
For about 6 months now I never know if the car is going to start up first time in the morning, espcially if I haven't driven it for a couple of day. It is intermitant and can go days without any trouble then out of the blue it decides not to start and I have to churn the engine over ( Buggering up the starter motor) for about 20 seconds or so to get fuel through. Once it is started it will stop and start perfectly all day untill I leave it to stand overnight. I have spent a small fortune replacing every pipe and O ring and so far 3 garages have failed to cure it or find anything in the diagnostic.
I noticed that the problem seemed to happen when the tank was about 1/4 full but now it seems to happen when the tank is between 3/4 and 1/2 full. (Coincidence??)
What realy puzzles me is why the fuel pipes and filter are full of air. It's as if the fuel is being drained back into the tank. There are no fuel leaks and I would imagine if there was an air leak it would show itself when driving not when standing.
Is it possible that a vaccuum is being caused in the tank and so sucking everything back, or am I on the wrong tack? I did think of putting a none-return valve in the supply line but the latest garage told me it would upset the sensors. (Poor things!) I've run out of ideas so any fresh thoughts would be appreciated.
Thanks,
John
For about 6 months now I never know if the car is going to start up first time in the morning, espcially if I haven't driven it for a couple of day. It is intermitant and can go days without any trouble then out of the blue it decides not to start and I have to churn the engine over ( Buggering up the starter motor) for about 20 seconds or so to get fuel through. Once it is started it will stop and start perfectly all day untill I leave it to stand overnight. I have spent a small fortune replacing every pipe and O ring and so far 3 garages have failed to cure it or find anything in the diagnostic.
I noticed that the problem seemed to happen when the tank was about 1/4 full but now it seems to happen when the tank is between 3/4 and 1/2 full. (Coincidence??)
What realy puzzles me is why the fuel pipes and filter are full of air. It's as if the fuel is being drained back into the tank. There are no fuel leaks and I would imagine if there was an air leak it would show itself when driving not when standing.
Is it possible that a vaccuum is being caused in the tank and so sucking everything back, or am I on the wrong tack? I did think of putting a none-return valve in the supply line but the latest garage told me it would upset the sensors. (Poor things!) I've run out of ideas so any fresh thoughts would be appreciated.
Thanks,
John