Runs poor P1689
 

Helping a friend out on a 1999 2500 with 142,000 miles. Came in DOA no fuel pressure. Bad lift pump and he must of drove it till it would not start anymore. I replaced the lift pump and it primed up and fired off after I cracked a few injection lines loose. I cleared all the codes and it idles fine and runs ok at slow to medium throttle. At any more throttle it just cuts out and goes to idle or it seems like idle.. It does not stall out it stays running. If you back out of the throttle it stays going. It may also cut out and in several times and then keep going holding the throttle in the same position. It maintains 10 to 15 psi of fuel pressure at all times. I cant seem to find much else wrong but the P1689 keeps comming back. I am thinking VP44 but not 100 percent sure if thats the way I should go. Ideas?

Any one????

I would try an apps reset.

I'd say the pump is gone.

I can try a reset but I dont think a reset would help for this condition.

Reset did not help. Erased the codes and it came back after a short drive. If you drive it easy 1/2 throttle or less you wont notice it.