Sprinter312 (camper) diesel problem revs fine but under load eratic

[charliefarlie]

Hi All
I have a Sprinter 312 5 cyclender td its a camper van which i have owned for last 3 years plus never any problem till now , always starts up from cold after preheat even after leaving it for a few months , yesterday i started it up started first turn of key as per usual after preheat , left it ticking over for a few mins then went to move it and it started missfireing as soon as i put it in gear it sounded realy rough , took it out of gear and it revved up no problem put it back in gear and moved backwards to free off brakes which it did but as soon as i increased the revs it started being eratic again and no power then decided to move it back further up in my parking area it did this with dificulty as not much power eratic , i had it out last summer and it did give a small hick up then, felt as if it was running out of diesel but couldnt be that as its always pretty full of diesel it then righted itself and drove as per normal ,on my return i put a new fuel filter in and started it up went no problem , its been sitting for a good while now not doing very much hasnt been the weather last summer would be lucky if it did 300 miles in total an awfull wet summer as am sure you will remember , today i started it up went no problem after preheat sounded just fine fireing on all 5 , soon as i put it in gear to run it down my drive the engine sounded like a bag of hammers and ran eratic lack of power stopped took it out of gear ran perfectly on tick over revved it up no problem then put it back in gear with clutch in revved it no problem let clutch slowly out started eratic again so floored it took off but still miss fireing then thought it had stopped it changed gear and started eratic again floored it again seemed ok but soon as slowed down it was eratic , then turned it around and came back up my drive still doing the same then parked it up and switched it off after switching it off it ran on of its own accord for about 2/3 seconds then started it up again after preheat light went off started no problem then noticed preheat light came on again plus a red light which has ldg or ldf on it . am wondering if its to do with the confounded computor plus of course lack of use .
The whole motor has only done one hundred and nineteen thou miles regularly serviced never lacked for anything . any thoughts would be great .

 

[WG M-B]

Get it put on star diagnosis! I have not had your fault before and have worked on many 312's

 

[charliefarlie]

Hi
Had it on a computor says its the glow plugs , personally i doubt it as it starts up from cold after preheat no problem what so ever after letting it tick over for 5/6 mins i can rev it up a little which it does no problem i have also heated up the engine prior to moveing it temp gauge to normal heater nice and warm but as soon as i put it in gear it sounds like a bag of hammers and it blows grey black smoke whether reversing or going forward it also drops power as not fireing properly , but as soon as put clutch in it revs up no problem no grey black smoke , so can hardly be a glow plug problem , how ever will test the glow plugs see if any have given up the ghost .
CF