ML270 CDI 2003 Not starting

david reynolds

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Hello.
I am hoping someone can point me in the right direction? I have recently replaced the seal on #1 injector and now cannot start the car without easy start. Once started it runs fine at all ranges of rpm. I took it for a good 20 min thrash all at high revs to get the engine warm and to thoroughly leak check the injector. I have replaced the CPS and checked all the fuel lines for air bubbles of which there isn't any. The battery is good and the car turns over normally. It just won't fire. I initially thought it could be a fuel supply issue but the surely it would struggle to run at high revs if that were the case? I am trying to borrow an OBD later in the week to see if there are any codes. There are no lights on the dash either at the moment.
Any ideas gladly received.
Thanks
 

mersum1es

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Most likely it is rail pressure problem. Is there difference is engine cold or hot? Measure injectors tank line leak. Filter hoses are good?

You could change low pressure o-rings (even no bubbles), and/but old hoses brittle easily so you may need to change all lines.
 
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david reynolds

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No difference whether hot or cold. All hoses from the filter look good too. Would rail pressure cause issues at high revs too?
 

mersum1es

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Usual problem is that air in system, or too high leak, prevents rail pressure rising enough when engine rotates at cranking speed. Once engine is running, effect of air or leak comes negligible when pumps produces more flow.

Check injector connector (which was open) that pins are not withdrawn, and plug is tight. Edit: though it should give problems in running too
 

M80

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After a start and you've had it running well will it restart soon after being shut down?
Are you leaving it long enough for the fuel to have run back to the tank if there is air ingress?
 
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david reynolds

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Have had it running for 30 mins on occasions then shut down and will not restart without the easy start. I have waited various lengths of time all with no joy.
 

M80

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Have had it running for 30 mins on occasions then shut down and will not restart without the easy start. I have waited various lengths of time all with no joy.

Doesn't sound like air ingress to me.
Anything that would prevent an early restart would be a pretty obvious fuel leak I would have thought.

I think common to all 2.7's was the lack of a lift pump, so a real bitch to prime after a fuel filter change. But doesn't seem to be relevant here.
 

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