Small chug when put into drive/reverse.

[Armalite]

1996 psd.
195k
No mods besides ts6pos. Exhaust..

Okay truck ran fine up in till yesterday morning. About 4 days ago I changed the oil/filter within the truck. After I did this I went and parked the truck for the night to let the fluids even out. Checked in the morning and all the fluids were fine. I went and replaced the air filter next. Then when I went to take it for a drive it started and idled fine. Put it into reverse and backed up. Then once I put it into drive it started to chug and die like it was running out of fuel. Went back and parked it and got out to drain the water separator... Nothing came out.. So I thought the pump went etc. Next morning I opened the water separator up to find that it was full. Closed it and tried to drain it and nothing came out. Finally drained it with the lid off to check if the plug was plugged etc. Nope.

So I installed a new filter. Truck starts up and idles fine.
No codes are all.
Then When I go in reverse/forward it after changing the fuel filter it started to do it but went away as soon as I hit the brakes and unlocked the TC. Maybe the trans is boggin it down? It have a leak in it. Added more fluid and the problem kind went away. It will still do this after I first put it in drive and start to move. But only for a few seconds.

Heres a list of what I've done.
Changed fuel filter
Cleaned FPR screen
Check for codes.. None.

Heres what im planning on doing.
Check the fuel pressure (normally it should be 55psi?)
Change the CPS. I just replaced this with a cheap autozone one a few months ago. This is what my truck feels like when my original one was failing. (No codes, first time it threw a code tho)
Maybe check the wiring harness for the injectors for corrosion etc?

Yah but heres a summary of whats happening...
Changed oil, truck starts to chug and seem it die. Full filter dosent drain with cap on. Changed the fuel filter, clean FPR screen. Truck runs fine at idle and only does this when put into drive/reverse for a few seconds.
No codes.
No smoke.
No loss of power or anything..

Thanks in advanced.

[Armalite]

More info:
It will only chug when put into gear for about 1-2 seconds then its fine. Never does it at idle.

Heres a video I found on youtube of exactly the sound/chug it made when it first happened

7.3 powerstroke injector pressure problems? - YouTube

7.3 powerstroke injector pressure problems? - YouTube

Thats exactly what my truck did when it first happened and went away when in park/brake applied. Never happened while idling.

Im gonna check the ICP sensor for oil under the plug tomorrow. But it seems like this problem is happening less. Still want to get to the bottom of it.

[Armalite]

Bump and heres a funny story for anyone reading.

I replaced my cps about 6 months ago with a grey one from autozone. I thought the problem I have now could be related to the cps so I went to advanced and bought a BWD? cps (black). Put it in and the truck idled fine. Drove about a mile and it felt like the engine was turning on and off for a split second. Keep going for about about another mile and the truck just shuts off. Started right back up and drove it home and it died 5 more times on the way back. Scanned the truck and it showed codes for p0344, p0340. Cps codes... Put the grey one back in and the codes cleared... Advanced didnt have any replacements so I said eff it and will continue to use the grey one.
But to anyone. Dont buy those BWD cps's.