2,5 does not start up, diesel pump

[tolstoj]

Hi all,
my 1995 2,5 suddenly does not start up. One evening i park it in front of my house and in the morning it cannot be started. Few times, after cca 20 seconds of destroing of the started it came up but only for few seconds even if i was trying to keep cca 2000 rpm. Strange is that no smoke is coming out of the exhaust (after 20 seconds of starting i would expect some).

Lexia diagnostics does not show anyhing wrong. But some strange noise is coming out of the top of Bosch pump. Stop ventil seems to be working fine.

Anyone already faced something simmilar?

Thanks for any advice.

[xmexclusive]

One of my 2.5's made those noises from the pump then stopped and would not restart.
There was no fuel reaching the pump just air from a very large air leak.
The pump sucks fuel from the tank so any air leak will make the engine difficult to start.
Fit a squeeze bulb and clear pipe in the fuel line just before the filter.
If the squeeze bulb sucks up fuel then the air leak is around the filter or pump.
If there is fuel keep squeezing and fuel will bubble out where the air leak is.
If you see air bubbles in the clear pipe then the leak is between the fuel tank and the squeeze bulb.
Usual place for that leak is where the pipe changes from steel to rubber.
That joint is down the back of the engine timing belt end.

John

This post has been edited by xmexclusive on April 17, 2012 12:05 am

[tolstoj]

Hi Xmexclusive, thanks for the swift reply. I believe that there is not air in the fuel as i kept high presure by pressing the pump on fuel filter but i will try tu put a clear pipe between fuel filtr and Bosch pump and check it while starting. Or do you think it is better to put it before the fuel filter?
I would like to switch the engine ECU for my spare one but i do not know the code for it, is there any way how to switch the code off?

[xmexclusive]

I can read probably supply an exchange ECU for a 2.5 reset to factory code.
Not all 2.5 ECU's are interchangable between cars, depends on age.
Three versions of the factory code were used during the XM production run.
0001 then 1111 and finally a second owner selectable code.
The codes are stored in the ECU so if you move the ECU to a new car then the code goes with it.
If you fit an incompatible ECU on a 2.5 the car fails to start.
You also get continuous relay chatter when the ignition is turned on.

John

[tolstoj]

you mean relay chatter within the Bosch pump, or somwhere else? Anyway it seems i have no other chance as to try to change ECU and i will see what will happen.
Thanks for your help. I will keep you posted with my findings

[xmexclusive]

I think the continuous chatter was the glowplug relay.
Glowplug signal is one of the ECU pins that move position between early and late 2.5's.
This is totally seperate from the chatter you get when the Bosch pump is trying to run on a very high percentage of air in the fuel.

John

This post has been edited by xmexclusive on April 18, 2012 08:25 pm

[tolstoj]

oh, sorry. I did not get it before. Great. I will keep an eye on the glow plug relay. I believe it is the one on the battery housing.

I love the car, but in the last time i am thinking about buying C5. From my point of view it is not so good as XM but you cannot stop the time. C6 looks great, but i did not hear much good thing about it.

PS: i hope my english is undertandable, in case it is not, let me know, please.

[tolstoj]

Hi,
i spent some time checking and clearing all electrical joins and relays i can reach without any behaviour change.

So i put a clear pipe between the fuel filter and Bosch pump and there is a lot of air in there. I will test to start with filling Bosch pump with diesel directly from a pet bottle. I hope it will start correctly and then it is clear that the problem is somwhere in the fuel intake.

[tolstoj]

Hi, the problem is solved. Air was coming in in the connection of tube and hose behind the engine :-(

but now it seems that there is another problem with alternator :-(