2003 cummins won't start!!
 

My truck was blowing greyish smoke when I laid into it so I swapped all the injectors and it fired up drove around perfect but a code came up p2146 I stopped at a buddies house and it just cranks no starting. He was towing me back an I dropped the clutch as he was towing and it fired right up then I drove around a while and brought it back to my shop shut it off and same thing. No start. I pulled all the injectors back out and put old ones in also finding I knicked a wire in the injector harness on behind the first plug in for the injector 1 which I shrink wrapped and then figured why I got that code. Anyways I tried starting again and my rail pressure was only going to 1400 psi. Tore it back down this time with the new injectors insuring I seated everything right and tight. 5-7000 psi when cranking now. I should also note the fass system is providing 18 psi steady. Just won't start for me it sounds like it wants to now just won't go for me. The odd time I'll get a code 0480 which is odd cause it's a **** near new fan clutch also p2509 which happens when the battery gets weak. Any help would me much appreciated as she's my work truck I'm grounded til I can get it going and shops can't fit me in!

First, welcome to DTR. I would suggest doing an independent load test on your batteries. You may find one or both bad. While you are in there, clean all your terminals and connectors. Weak batteries won't turn over the motor fast enough to get the rail pressure up to where it should be, or cranking may draw the batteries below Vmin. (someone may correct me on that)

Another way to test is to hook up some jumper cables to another truck and try to start it. If it does start, I would definitely be suspicious of the batteries.
Back to morning brew . . . [coffee]

thanks for the reply I've tried new battery's and boosting as well no luck!

OK, go here for a good read on the 5V wire behind the AC compressor. Don't look for the photos, though, as the thread is from way back.

Good Luck