Hi guys i got to work today on that 99 super duty i was talkin bout on the other topic and i did the fuel sender mods inside the tank and replaced the quick connects with hose and clamps on the suction side. Thought for the heck of it i'd check it out with the pump i had in there that was whining, turn key on and no noise, NONE, just 72psi of fuel pressure, so i fire it up and instantly starts better and idles better. So back it out and let it run for 5 minutes and jump in still has 72psi fuel pressure. Take it out and cruise for 5 miles. Pressure jumps down to 68-70 when under light throttle and cruises at 70. Go up a hill with cruise set it drops to 66-68 so not much when it lets off it goes to 72 and then cruises at 70 again. So finally it's good and warm. Stop and floor it and hold it to 85mph, pressure never drops below 64 and when it shifts it jumps to 70 then slowly drops to 64 and holds it in every gear. Let off and pressure goes to 72 and back to 70 when it cruises. So i hammered on it 4 more times with the exact same results. So then i cruised 20 miles and back to shop. It's idling while i have lunch then gonna drive it again but i'm thinkin problem is solved. Let you guys know for sure after work. I'd like to thank you all again cause i could be dealing with this for a long time without knowing these mods. So it looks as if all is well as it NEVER dropped below 64psi no matter what i did.

 

Also fuel pump is quite, idle quality and throttle response is so much crisper and the noise the engine makes what cut in half!!!!!! No more cackle or "rattling" noise at idle, it just runs!!!! Another update after second test drive this afternoon.

 

Good info BL! Just one more documented repreve for Hutch (but then we FTE'rs have known that the intank and pre-pump mods do nothing but good things for the engine).

 

Good Job. Glad you got it fixed! You may receive more customers after he starts bragging to his friends about how quite his motor is.

 

Ya and i also like the fact that the fuel pressure doesn't fluctuate 10psi anymore either. At least now i'll know what to do next time i see the problem. I drove it again after letting it idle for an hour over dinner and got the same results with the fuel pressure, stays at or above 64 on WOT and steadys out at 72 when idles or cruising. So i pulled the gauge and put the fuel pressure tap plug back in and sent it out the door.

 

I think a new pump would keep it at 72 at all times. I have a new pump sitting on "the shelf" and will go in when the weather gets warmer... Mine drops a few PSI under accell and even more when running BIO. But mine has 200,000 on it.

 

I would have been VERY surprised at any other outcome.
Congrats on a job well done.

 

Thanx kwik i'm not worried bout a slight drop like that at all as long as it doesn't go under 64 it's got plenty. Customer seems very happy with it right off the bat he noticed the smoother and quieter idle!!!