I replace my fuel pump with waldo 255. Fuel gauge read 58 psi with no vacuum and 50psi with vacuum. when turn the key pump comes on and goes to 60psi and when pump goes off drops to 0psi. The other problem is that my a/f +17 at idle. I changed the fuel regulator already. What do you guys think.

 

check valve problem on pump

 

How does it idle? 17:1 is pretty lean some widebands arent very good at idle. What are your NB O2's and trims telling you at idle?
How does the truck drive. How's the idle in gear?

Your FPF sounds fine, and I agree sounds like the pump is letting fuel back into the tank. Could have a leaky injector as well.

peace
Hog

 

Well replaced the injector with 42's when i did the pump. I'm wonding if just need to redo my V.E table and short fuel trims were +35% when a/f cam back around 15 then when rev up the trim go back to +5% and the a/f goes to 19.1 and works way back to 35% on the short fuel trims. I'm thinking i should redo my v.e table for the bigger injector. I'm runnin co3 sem-closed looped and changed my fuel rate allready.

 

Yeah you better tune for those 42# injectors.