I have an 89 7.3 n/a f350,and I'm kinda stumped on what this issue is.under hard acceleration,the truck runs normal until about 2900 rpms,after that it will throw you back in your seat and starts sounding like a big block gas motor.once you let off the gas,and it returns to idle,it will sputter for 5-10 seconds and then run normal again.all 8 injectors are new,so I was thinking the timing may be a little off or the ip is worn? Any advice would be greatly appreciated.

 

You are suffering from air cavitation .... your getting air in the fuel from some where .... I have a solution though .... @ the lift pump run a new leingth of hos back to the bed and put in to a fuel can ..( keep in mind you wont have a return to this tank so it will run out quick @ high RPM ) ... run it for a bit rev it up multiple times ... if it is better then you have your solution .. you need to redo your fuel lines ... I used Gates brand Bio-Line ... about 90 bucks for a roll @ local car quest ... zip tied them all up from tank to the pump and re-did the return and the feed line ... runs line a beast now ( well before the Head gasket began leaking that is ) .. give it a shot ... can just run it short if you want I run mine back to the bed to give me ample time to shut it down ...

if this dosent help ... replace your factory water/fuel seperator with a NON-Bowl style ... like a Baldwin BF-1222 for instance .. if still getting air and problem persists .... the fuel feed line from the water/fuel seperator has a rubber like bushing ... air can enter here, or at the seperator housing .... also the small window used to adjust the pump has a gasket behind it .. mine was leaking and caused some issues ...

if the problem still is present after all this ....... ... PM me

 

Thanks for the advice,I'll have to try that.hopefully it will alleviate the issue

 

keep me posted .... I usually check here 2-3 times a day to see if help is needed ....