[Chevyguy55]

1996 k3500....This truck is killing me ive rebuilt the entire engine new glow plugs injectors lift pump etc only thing i havent replaced is injector pump she runs and drives fine no smoke thats out of the ordinary no stalling and no surging just takes about 20 seconds to start up hot or cold i can start her and shut it back off and still takes sane amount of time i bought a new pmd and that made it way worse she would barely run and wouldnt go over 800 rpms so i hooked my old one back up only code that pulls up is crank shaft sensor i replaced but code still shows up

 

[OkDually]

Did you replace the crank sensor with an AC/Delco? Aftermarket electrical parts will bring gremlins
Try installing a piece of clear fuel line on the return side of the IP to help locate any air in fuel issues

 

[Chevyguy55]

No replaced with autzone brand also im hearing i have to do a relearn when replacing the sensor is that true

 

[Chevyguy55]

Can the crank sensor cause hard starts

 

[OkDually]

No replaced with autzone brand also im hearing i have to do a relearn when replacing the sensor is that true

Replace it with an AC/Delco brand. No relearn that I am aware of atm...

 

[OkDually]

Can the crank sensor cause hard starts

Yes

 

[Glagulator]

CPS change does require a re-learn per the FSM.
Will probably still run.
I'd be pulling the engine harness out from under the intake and inspecting that.
It can be put back on the pass. side of the intake over the runners, conns. will still reach and future diagnostics will be much easier.
CPS code will put you in a kind of limp mode.

 

[Chevyguy55]

I just pulled cps out will get another one tomorrow and find someone to do the relearn on the truck and will go from there

 

[Chevyguy55]

CPS change does require a re-learn per the FSM.
Will probably still run.
I'd be pulling the engine harness out from under the intake and inspecting that.
It can be put back on the pass. side of the intake over the runners, conns. will still reach and future diagnostics will be much easier.
CPS code will put you in a kind of limp mode.

I've gone over the harness a hundred times and checked grounds and added a few soory if i come of as rude just frustrated ive replaced and checked everything and also just pulled cps out and its stupid u have to move power steering bracket smh

 

[Chevyguy55]

Replace it with an AC/Delco brand. No relearn that I am aware of atm...

Really so relearn is just on generic parts ...deff will find one

 

[OkDually]

Really so relearn is just on generic parts ...deff will find one

As member Glagulator mentioned there is a relearn process when replacing the CPS. Using the AC/Delco Brand ensures no electrical gremlins.
Aftermarket electrical parts will bring you gremlins in a 6.5L

 

[Chevyguy55]

As member Glagulator mentioned there is a relearn process when replacing the CPS. Using the AC/Delco Brand ensures no electrical gremlins.
Aftermarket electrical parts will bring you gremlins in a 6.5L

So still have to relearn aith acdelco

 

[Glagulator]

Re-learn is needed to get timing just right, your engine should start right up unless there are other problems.
I have never needed the re-learn myself, timing always checked OK after CPS replacement.

 

[Chevyguy55]

Ok and just to pick yalls brains alittle more like i said i rebuilt the engine im hearing people say u have to time the injection pump that it rotates on the three bolts i never did anything but bult it tight

 

[OkDually]

Ok and just to pick yalls brains alittle more like i said i rebuilt the engine im hearing people say u have to time the injection pump that it rotates on the three bolts i never did anything but bult it tight

DS4 Injection pumps need timing verified.
The OBDII procedures are listed in the 6.5L FAQ page.
You would do the KOKO procedure to get the IP into the ballpark and then with the correct timing software you would verify/set TDCO

 

[Chevyguy55]

If its out of time could that cause the hard starts ...sorry for all the questions this is my first diesel

 

[OkDually]

If its out of time could that cause the hard starts ...sorry for all the questions this is my first diesel

Yes

 

[OkDually]

Start with getting the correct CPS then follow all of the advice member Glagulator gave you in post #7
Even though you have gone over your harness recheck every inch of that harness including connectors/pins
Look for corrosion, worn thru wire insulation,anything that looks suspect

 

[Chevyguy55]

She starts and even sounds better now changed out cps for acdelco takes about 3 seconds to fire up ......did rind out that glow plug relay is bad but glad ot doesnt take forever to start huge thanks to you all

 

[OkDually]

She starts and even sounds better now changed out cps for acdelco takes about 3 seconds to fire up ......did rind out that glow plug relay is bad but glad ot doesnt take forever to start huge thanks to you all

Glad you got the issue resolved.
Thanks for giving us an update!