My diesel 2.8 manual dodge nitro is hard starting when i park it for around 2 hrs, sometimes it doesn't start at all. and if it starts,black smoke from the exhaust comes out.im confused about this,because there is no problem starting in the morning.what could it be?

SOURCE: F-350 turbo-diesel hard starting

Imagine the white smoke is unburnt diesel. Anybody standing in the middle of it will be able to tell you soon enough.

Most likely culprit is that one or two of the glow plugs aren't getting hot enough. Usually just that the plugs need replacing, but worth checking first that the busbar which runs between them all is getting +12V at the appropriate stage of the process.

A.

SOURCE: 2004 Ford F350 diesel, changed fuel filters hard starting

Pull the filters and ck for plastic or o-ring in wrong place. Something is up in the filter. 

SOURCE: White smoke coming from the exhaust

sorry to inform you that the cylinder head gasket needs to be replaced or you have a cracked cylinder head.......either repair is expensive

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SOURCE: It is sometimes hard to start my jetta tdi. When

It is hard starting my VW 2003 Jetta. It usually take 5 to 10 cranking before it turns over. Then it run normally. It only happens when the car has not been driven for about 6 hours.

VWjase

SOURCE: NO POWER ON COLD START UPS AND BLACK SMOKE COMING

are you letting the igniter heat up before starting it?