86 300gd cut out low revs,then complete halt while driving.
Folks,
Have looked through the diesel section for some diagnostic help but cant find exact match, though an inline filter at tank seems to fit bill.
Summary of symptoms.
G was running fine.
One day began to feel like it was about to cut out when at idle, increasing the revs sorted this initial issue out. Didnt drive G for weekend. Next drive, G started OK and again needed higher revs to keep from cutting out. Drove about 6 miles down the road and then G totally lost power.
My assumptions:
Fuel delivery problem, probably blocked filter or filters.
Actions to date:
Changed fuel filters inline and cartridge and attempted to bleed system. Unfortunately the manual priming pump leaks quite a bit of fuel and I have not heard the rattling sound indication that the system is fully bled, though I can see that fuel passes through the cartridge filter and the fuel line seems full. The engine seems to want to catch when you turn it over but doesnt.
Any thoughts on next steps ?
Hi Fiachra any smoke? suggest you look for contaminated fuel....if it proves to be fuel you may have to get the injectors serviced.fuel that has been "cleaned" with acid can take the lining of the inside of the fuel tank which means purging the complete fuel system.....
Hello fiachra,
Do not overlook the glow plugs, if these do not glow you will not start!
Are the valve clearences o.k.? (If adjustable, that is).
Check to see the fuel cut off valve is actually dis-engaged whilst starting or if the pump has a lever instead, that, it is di-engaged!
Come back with more info. please.
Regards & Goodluck,
I Have to say, fair play, gwoa has to the most helpful owners association Ive ever come across, two replies from very knowledgeable people in a very short space of time, only to willing to help and diagnose a problem without even seeing the vehicle, something that is very difficult!
big pat on the back to pistonhead&fixwin38 :D
Hi Fiachra there is a filter on the end of the down pipe into the tank..remove the rear carpet .observe a square panel held with four star head screws..remove the panel to expose two pipes and the wires to the fuel guage sender remov the pipes and the wires and the screws at each corner gently lift the sender unit vertical for about 50cm..look out for the sensing wires for the fuel guage..there may be a filter at the end of the longer pipe.also look for sediment or sludge which collects in the bottom of the tank.....if you drove it for some six miles before it stopped and the first symptoms were "rough idle" it could be sucking air from a fractured fuel line..any smell of diesel around the engine or back end?? re bleeding..the primer pump not very efficient anyway.best bleed (but messy) is with a good battery... have some body crank the engine as you slacken the nut on the end of each injector..it will spit diesel until the air is removed and then spray s steady stream.as it sprays tighten the nut in mid spray and proceed to the next one.the chances are that the engine will run very rough after you have bled the fourth injector.....if you cannot get diesel to spray then you have an airleak somewhere in the system.if you are not using an MB inline filter or the correct canister filter you could be sucking air from these points... the heater plug light should glow for 10 seconds after you turn the key and then go out.if it does not light at all you could have a problem with the heater plug relay....
Thanks Peter, Will give it a go.
OK Long delay in getting back to the Forum - Still no joy with getting started.
Have checked the tank filter which was clean, then checked to see if there was a blockage in the fuel line to the cartridge filter by hooking up fuel can to inlet, again no start. bypassed filter and went to suction side of injector pump, no start, cracked open injectors to see if air in system was problem, got small weeps from open injectors not the high pressure I was expecting, again no start. Was concerned that there was a block in return line and thus back pressure on injecctor pump causing issue, disconnected this and ran to bucket, again no start. I think I have eliminated everything except an injector pump problem. I did get it to run on a quick spray of ether so confirmed it can turn over. Anyone and ideas beyond the injector pump or injectors ?
Any suggestions appreciated.
hi you mentioned that your manual priming pump is leaking out fuel, well if it leaks out fuel it could also be sucking in air when not running. had a very similar fault on my truck, changed the manual pump (only a tenner from bosch main dealer) starts alot easier and runs smoother. the manual pump is a dodle to replace, it is different to the original one as it has no wind down top, its like a small bike pump. also be carefull if you have been diong lots of cranking with no starting as you may hydraulic the engine and damage piston rings or head gaskets. will it start under tow and how fast is cranking speed. best of luck lynxman, also if you want the number for the new modified pump contact me.
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Thanks for replys.
No smoke. Only used good fuel.
How long should it take to bleed system after replacement of filters ?
I keep pumping manual pump primer but have failed to hear anything like an audible buzzing sound as indicated by the manual. Is the sound really distinct ?
Another question, Is there a filter on the fuel tank which I should look at ?