Low boost!!!
 

So I have 50hp ddp injector that are new, new denny t stage 2 fuel pin new lift pump and new fuel filter. Now I had full fuel screw in like 2 turns and the idle was really high and would have trouble starting. And when driving down the road it wouldn't go past 25 psi of boost. What would this be?

More info required.
What model engine?
Intercooled?
Gearing?
By driving down the road, this cruising. up hill or towing?
What RPM?
Do you have a pyro installed?

Drivin in 4th gear at like 1400 rpm and when you get on it hard it builds boost but not as quick as it should and only builds up to 25psi and ya pyro reads like 800* and it 89 non I/c cummins

I forgot to mention it feels like it stops getting enough fuel when floored and that's why it may not build more boost. Any ideas?

By no means a guru on these but a couple of more points.
If no smoke when this is happening and the low temps would indeed seem a lack of fuel.
If it is still the stock turbo it will be laggy down low.
How was it running before adding these parts? Did you do all the changes at the same time.
May need to add a pressure gauge to the fuel system to confirm your pressure.

I got the motor all apart . But I put all the upgrades in it at same time and its stock turbo. I got the ffs about 1 1/2 turns in and star wheel all way in and smoke screw all way in. Also have stage 2 Denny t fuel pin. And when at wide open throttle it barely makes 20lbs boost and doesn't smoke at all. And barely smokes at lower rpm

But my exhaust temp is getting hot like it getting a lot of fuel

Fuel PSI would be good to know, is the pin inside the pump that rides on the fuel pin getting full movement or is it stuck? What type of lift pump do you have? If stock replacement than it might not push enough fuel for your needs being rated at 3-6psi.

i havent had the chance yet to get my fuel gauge hooked up, but my motor is idling at around 900 rpms and when i turn the idle screw down it doesnt change the idle at all. and when i advance the pump a 1/8'' it gives it no extra power really. now when i drive down the road it feels like im only getting half power and it doesnt smoke or haze at all when at wot. and i was told it may be the brain, but what is the brain?