will not start w/o a little shot of starting fluid. replaced #1 injector cranked up ran pulled it out of the shop and will not crank back. need some help its got me stumped. thanks

 

More information please.

You replaced an injector? Why? did you check for etch marks on the cross over tube?
Would it crank before you replaced the injector? but as of NOW it will not crank? If it wont crank you need to fiqure out if you drained your batts, or killed a fuse, or relay and check the starter. Now for the fuel injector.

The cummins ISB Common rail fuel system requires 5000 psi minimum of fuel rail pressure to start the truck. Since the common rail is a EUI system instead of a mechanical fuel pressure system. The rail sensore in on the mid rear of the rail. Their are three reasons why the rail will not build adequate pressure. First is the crossover tube is allowing fuel to leak past the injector and cross over tube which will not allow to CR to build 5000 psi, their is a tool you screw on the injection line to block that injector and cross over tube and see if that is the cause. Second the check valve in the common rail is not functioning properly and is releasing fuel from the fuel rail. Last, the high pressure fuel pump is no functioning up to system requirements. But since you replaced the injector im willing to bet the cross over tube or a fuel leak.

 

it would no crank before I hated to do it but it would start with a little shot of starting fluid and run fine.the mechanic said when he pulled the tube it was loose and there was a little fuel around the injector.im going to tell him to check the check valve and see if that does anything

 

Common rail that cranks but wont start w/o a shot of ether means your high pressure fuel pump can't supply enough pressure at cranking speeds to fire the injectors. This is attributed to:

1) Control Valve erosion
2) Cracked injector bodys
3) Bad orings
4) loose cross over tubes
5) bad over pressure relief valve

It sounds like you found the issue with the #1 injector cross over tube being loose.

 

Mine does this too. Fuel to the CP3 but no fuel at the rail. What should I check next? thanks