I just replaced a pump,and can't get it timed.It reads 20 degrees actual timing and barely starts.I can get it to 18 degrees,but that's it.I also did a water pump and checked that the ip gear and cam timing marks were lined up.is it possible to have a bad factory reman ??

 

What year is the truck?
The electronic IP's must have the ECM learn the new IP location and a scan tool that can force this to happen is required depending on the year.

The procedure is called a TDCO relearn.
Can't help any more than that without knowing the year.

 

it's a 1999 gmc 3500.I tried to re lean tdco,no luck

 

Google KOKO relearn if you have a scan tool that has the ability to display a TDCO value.

There can also be NO codes when doing the relearn and temp MUST be 170F+.
Otherwise you will need a scan tool that can force the relearn like laptop programs such as Autoenginuity or carcode.

Once a relearn is done you have to interpret the TDCO value and adjust the IP and redo the relearn to get in spec if not there already.
Stock is: -0.25 to -0.75
Performance is:-1.50 to -1.94,the negative(-) is important,it denotes advanced timing,if the result is positive then the timing is late and the IP needs rotated towards the drivers side.

Small movements of the IP make big changes-1mm is about 2 degrees timing change.