My truck has started having long cranks and rough idle when first started for the day. My rail pressure drops to zero within 10 seconds of shutting down the truck, so I figured it was a leaking injector. I watered the exhaust manifold this morning and fired it up, and all the cylinders burnt off the water within a minute or so, except number 1, I could hold my hand on it even when the others were hot. The truck was still making white unburned diesel smoke at this time, so i figured number 1 is the problem. I shut it down and pulled the valve cover and then went to pull the injector line, but the connector tube was moving instead. I finally got the line off, and the connector nut was barely hand tight. So now i am thinking that there was a fuel leak at the connector and injector, and that is why the rail pressure is dropping so fast. My question is, would that also cause unburned fuel in that cylinder? If the injector wasn't getting full pressure due to the leak, maybe it wasn't spraying fine enough to burn until the engine gets so temp. BTW, the truck runs and starts great once up to temp. Anyway, I am going to re-torque the connector tube and see if my rail pressure will hold.

 

Ok, so I tightened up the connector nut, put everything back together and no difference, still long starts and the rail pressure drops once the truck is shut off. I pulled the Injector and will be picking up a new one tomorrow. I would love to change all 6, but I just don't have the money right now.

 

i would check the torque on all the connector tubes. Also may want to get a new tube to replace the one that was loose incase the tip got fubared. I would also check the oil for fuel or just change it good chance with a tube that loose you were leaking some fuel into the oil. Make sure to get a new copper washer for the new injector.

 

Ya, have a new injector and tube on the way. No fuel in the oil, as far as I can tell, in fact, my oil has been going down on the dipstick, there seems to be more blowby now :P Hopefully the new injector will get my by for a few months until I get working again and can change the rest.

 

I'm by no means an expert, but once the truck is shut off the RP should default to zero, right? I know when I shut mine off the RP gauge stops at 5k and then when the key is cycled it goes directly to 0 until the truck fires, then it goes back to 5k.

Not trying to hijack....just need a little clarification.

 

Your rail pressure gauge does that because of how you wired it. There are three options for power to gauges--hot at all times, hot in run and start, and hot in run only. Most people wire to hot in run, it takes a little more work to find a wire/fuse that is hot in run and start.

I wired mine to hot in run/start and it shows pressure while cranking as well.

 

Well, that would have been a nice option to have listed in the instructions .