Intermittent starting problem on OM602 983 (290 GTD)
Hi All
I own a 290 GTD with a new engine installed about a year ago and has done approximately 25k km's. Since installation, it from time to time fails to start at first crank. When this happens it can be cranked for 10 seconds and it will not fire. Stop cranking and wait 5 seconds or maybe less and she starts immediateley. This happens whether the engine is hot, cold, fuel tank full or near empty with no clear pattern. Sometimes it will not happen for months and then suddely three times in a row. The agents (the engine still carries the one year guarantee) have tried a lot of things all trying to eliminate a perceived air problem. Now on my vehicle the fuel lines from the fuel heat exchanger is translucent and i can see the air in the pipe just upstream of the front (near radiatora) fuel filter, but even then the engine would start immediately, so i am not so sure that it is the air causing the problem! I have also heard that these bosch rotary pumps are very tolerant of air.
I have posted the problem on P3 but no similar experience was reported, exept one member who had an air problem caused by the fuel heat exchanger o-ring, which I then also changed (although it was new).
Are there maybe anybody on this forum who had a similar expernence or an in-depth knowledge of the pump to comment on the air problem? I am obviously worried about the longevity of the pump pumping air since i know what air does to a water pump!
Any comments will be appreciated
Regards
Freek
have you checked the cylinder preheat system for an intemittent fault?
Yes Bosch rotarypumps ARE very tolerent of air
I know, I witnessed it.
not in a "G" though.
Other than that I am of no help
Good luck
Marcus
Air leaks can occur at the o-rings of the push on connectors of the fuel pipes either at the fuel filter or fuel pump, have these been rewnewed? It is not possible to visually examine them to say they look o.k. , just renew them. Do so for all ends of the fuel hose.
Your glow plug relay could be a source of same fault, it will be tedious, but every time the engine does not start check to see if the glow plugs get power to them. Get the glow plugs to be tested, even if you get one g/plug down or two working on low power it could give starting problems.
On the whole, it points to a fuel problem or most likely, intermitant air leak.
If you fuel filter has a bolt going through the top of the filter housing to secure it on the mounting, renew the two rings on the nut too.
Hi it appears that when the heater relay light goes out the engine will start..even hot the light comes on for 2 to 6 seconds so an almost immediate start.if the heater relay is faulty it may not operate the glow plug failure sequence or heat the plugs every time you turn the key....
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Gents, thanks for the responses
Will the glow plug failure result in a non start even if the engine is hot? Will the glow plug light not stay on then? I will see if the glow plug light stays on in this condition, or have somebody check the current whilst this is happening. What i will do is to put the multimeter in the car and then it will never happen again (as per Murphy) the problem is exacerbated by exactly this - it happens intermittently!
The fuel pipes generally have normal clamps except for in the fuel heat excanger, where the o-ring was replaced.
I will keep you posted on this
Regards
Freek