My truck will start drop to about 2psi jump up to 14 then quit. I start it again it stays at 14 psi. and runs great. Sometimes it will stop when i put it in gear. Then run great. I just put in upgraded ATS tranny.I do not know where to start looking for whats going on. Can you guys give me some leads? Thanks ahead of time Jim

 

I think the 2 psi is your problem .
I do not remember , but 7 -10 may be the min. , you may need a lift pump .
But do not buy any parts till you get a good diagnosis .