Sprinter Starting Problem

[miker777]

Hi guys, I have a 1996 Sprinter 208D Motorhome and I'm having difficulty starting it after leaving overnight.
It takes about 2-4 minutes of tuning the engine over on the key before it starts to try and fire up, whilst turning it over on the key, you can see it trying to gas up as smoke comes from the rear exhaust, then it tries to start and by keeping the engine turning on the key it splutters into life.
I have changed the heater plugs (new of course) and recently a mechanic by-passed the relay and fitted a new one with a push button switch, but this had no effect, even with the button pushed for approx. 25-30 seconds.
It just feels like there is no fuel coming through and after a couple of minutes turning the engine over it fires up, I have checked to see if fuel is coming through and it is and there is a live feed to all heater plugs.
Any advice would be much appreciated.

 

[yorkshire1]

air in fuel

if yours has the clear plastic fuel lines running to the pump and filter itll more than likely be the O rings on either end of them, even though it looks like fuel is there ,there will be air bubbles in the system somewhere

 

[Jasons76]

Classic air in the fuel symptoms,replace the o rings and you should be fine.

 

[miker777]

if yours has the clear plastic fuel lines running to the pump and filter itll more than likely be the O rings on either end of them, even though it looks like fuel is there ,there will be air bubbles in the system somewhere

Thanks for the info : yes mine has the clear plastic fuel lines, when you say O rings on either end of them, do mean in the union at the Filter and pump :as I assume there are O rings inside the unions? I felt that it was something like this as the heater plugs etc work just fine.
Once it has been started in the morning after sitting all night, it is difficult to start, but then will start all day long until leaving it overnight again.

 

[yorkshire1]

air

yes each plastic pipe has an O ring fitted as you say on the union

I cant say exactly Im not familiar with the Sprinter system as I have a 1998 diesel 5 cyl but I would have thought similar issues

the pipes are pushfit into the filter once the metal plate is removed on top, the pipes on the pump and preheater if you have one you push the white clips in and then they pull out

if your pump has the black plastic solenoid fastened on the side it also has an O ring behind (held on by 2 studs)

the prefilter has an O ring sealing it to the aluminiun housing aswell as a small one on the end of the pipe going in to it

hopefully replacing these will cure the problem, if you can see any bubbles in the clear fuel pipes with the engine running see which pipe they appear in first

 

[Roxie]

Firstly get the wiring put back as it should be. The glow plugs should continue to glow after the engine has started for some time, this is because the pre chambers will still be cold.
Secondly I don't think you will have the o ring problem described as most of your fuel lines are sealed with copper washers. However you do have a fuel problem. The fuel is somehow draining back to the tank this will be because of air getting into the fuel lines somehow. You will have to check each line and its end fitting whatever seals it is in good order don't forget the small leak off pipes between the injectors and the blank on the last one. If the problem still persists after this then next you should change the residual fuel pressure valve in the fuel pump. If this does not sort the problem out then you have missed something and you should start again.