My 03 in sig has trouble starting if it sits for 24 hours. If temp is 60 or above, it cranks for 5-10 seconds. If it's below 60 or so, won't start. Warm, she starts fine, no hesitation.

If I plug in the block heater for an hour, she fires right up.

I've retorqued the fuel supply lines to the block.

Codes: (I DON'T HAVE 4WD)
0477 Exhaust pressure Control Valve Low
0837 4wd rationality
0838 4wd switch low
0839 4wd sensor high

The wait to start light comes on and I wait till it goes out. Have tried cycling the grid heater several times, still won't start. (anything to test on grid heater?)

FP gauge shows good pressure (12psi) to the CP3.

151K on odometer. Changed #4 injector at 145K for similar problems. Didn't change the crossover tube. Worked great for 4-5K miles. Idles great, tows great, batteries also good. Ideas??

 

Try to bump start it. Just bump the key quick, don't start it and let her sit for another 20 seconds with the key left in that position. This will prime the system, then fire her. If she cranks up just fine that way a few times you know you are getting air in the system somewhere.
As far as the 4wd codes on a 2wd, IDK. Search the net, good luck.

 

Will give it a shot this weekend after it sits for 24 hours. Looked at my fuel line and there are some surface cracks, so air may be the answer. Thanks for the insight.