I've had my 3.0 CRD (with Mercedes engine) to two different Jeep garages. They have replaced multiple parts but the problem remains unsolved.
When I attempt to start my car after it's been sitting for 12 hours or more, it doesn't want to start. It can take up to 20 short bursts of cranking the engine before the engine fires up. Once it does actually start then I can go about my business for the entire day without problems, stopping and starting the engine multiple times. The car runs smoothly at all times once she's up and running. AFAIK the glow plug control module, the anti theft module and locking control have been replaced, The battery and charging system have been checked. The fuel system and pressure have also been verified. The computer system is not throwing any error codes. The injectors have NOT been tested to my knowledge.

I don't know where to turn to hence my presence here! Would appreciate any pointers that you good folk might be able to give me. Thank you.

 

Hi Again,
I have still not got my Jeep to start properly. On further investigation I can confirm that when cranking the engine the glow plugs are not being powered up. Since the glow plug control module has already been replaced, the only things remaining would seem to be the ECU and it's connection to the glow plug control module. Replacing the ECU is a big deal financially.
How likely is it to be the ECU? Anything else I should check out before replacing the ECU?

Thank you for any advice offered.

 

My mechanic has cracked the inactive glow plug problem. He replaced the alternator and bingo, the glow plugs are working again and the car now starts properly. The mechanic doesn't know why replacing the alternator should fix the problem - he sees no direct relationship between alternator and glow plug control system.
Can someone explain ? I'm stumped.