I just installed DAP 75HP injectors and my fuel pressure dropped from 18 psi down to 12 psi, I have a fass DDRP.  After it idles about 20 minutes it will go up to around 17psi, haven't driven it yet to see if it will hold it WOT. Is this normal?

Is the truck warmed up or cold?

 

39 minutes ago, mountaindan said:

I have a fass DDRP

 

Pump is struggling to pump the cold thick fuel. As the fuel thins out with some heat from the engine then it starts to rise. 

voltage also stablizes after things are warmed up

Fuel should have been warm, it was 75deg here yesterday and today. The voltage could of been down I cracked it a bit to get it bled. Didn't know if the bigger injectors would make a difference or not. I do have a manual gauge.

 

Thanks for the reply

Well I hate to post this my problem was the snubber valve to my gauge got closed while I was installing the injectors, was leaking slow enough to move the gauge after it ran awhile. 

Glad it was a simple fix.  I've done that too.

I've done that three