CAT 3126E acceleration power loss after fuel filter change

[Phaeton04]

I installed the new water/fuel separator filter and made sure the old gasket on the thread end was removed and new gasket installed. Filled up the new filter with fuel making sure to plug the center hole. installed the new fuel filter and started it up and test drove it.
It now it has Very low power when accelerating, it shakes but very low acceleration power.
I also installed a new air filter.

What could be wrong, It ran great up until I changed the water/fuel filter. This is on a Cat 3126E (HEP20882) with only (1) fuel/water separator.
I have now installed a total of 3 new filters with the same results. using the following filters Cat 1752949, Baldwin BF1268 and now Wix 33783 w/bowl.
Freightliner said the original filter was Racor 3203 (Alliance ABPN12232FRT03)
Totally confused. What do I need to try now.

[Phaeton04]

Hi Enblethen,
I do not have the hand pump on my unit.
Hi Mexicowanderer, thanks for the suggestion.

[MEXICOWANDERER]

40 some odd years ago I installed several RAcor filter assemblies on a fleet of plow trucks with 3208 engines. It didn't matter how careful I was, I had to bleed lines from the filter to individual injectors. I was fortunate to have offset tubing fuel line wrenches. Hint: do this on concrete or dirt because you'll lose more than a gallon of fuel.

[enblethen]

Does your Cat have the hand pump on the fuel injector pump? if it does make sure it is closed.

[Phaeton04]

Thank you enblethen.

[enblethen]

Here is an article on Cat low power. 3126e article

[Phaeton04]

Hi S Davis,
Thanks for the reply.
This problem started after I initially changed the fuel/water separator filter. I have since put on a new air filter as well as try 2 other fuel filters. But, I will still look at the MAF sensor just in case..

[S_Davis]

Could something have gotten on your MAF sensor when you changed the air filter?

[Phaeton04]

Thank you for the reply...

[enblethen]

Could be air between the injector pump and injectors. Could try bleeding fuel lines at injectors.