So I was working on a 99 f350 and it would occasionally have low power and when you turn it off for a min and start back up it would be fine. So I did my diagnosis and found the ipr was sticking. I told the guy bring it back and I'd replace it because for some reason ford didnt have one that day. So then he told me that it was getting worst so he brought it in and I replaced the ipr and no more low oil pressure high ipr duty. Took it for a test drive and it was fine for about three blocks then started missing really bad and no power could barely go 15mph. The the highest the ipr got was 35% at about 2500psi icp. Noticed the fuel was pretty low so figured it was running outta fuel put fuel in and still same problem. I opened the fuel filter to look whats going on and it was obviously water and diesel. I don't know how much water compared to diesel it was but enough to not be diesel color and more of a clear white color. Im pretty sure I have to drop the tank and get good fuel in it but does that what it sounds like the problem is? Because before when it lost power before I swapped the ipr it would have about 1600 psi at bout 65% now the ipr doesn't get high and oil pressure is nice but no power and and missing. Plan on dropping tank unless someone points me to a different direction. I might be asking stupid questions that I pretty much answered myself but just wanna be sure I'm not going backwards. Icp at idle is about 490-530 at 10-12%. Thanks

 

Sorry forgot to say ipr at wot now is about 35% at about 2500psi. But missing and won't go passed 15mph. If you let it idle for sbout 15 minutes it will smooth out and run decent for about 3 blocks then act up again

 

If you suspect water, drain the fuel filter bowl into a clear jar and look to see how much water vs. diesel is in there since the two won't mix. The water will be on the bottom, the diesel on top.

Is the CEL on? Any codes? Have you checked fuel pressure? If you decide to drop the tank, be sure to take apart the mixing chamber and clean the cylinder screens inside. That or just do the in tank mods. Welcome to guzzle's In-tank Hutch Mod Web Page

 

Ya it had a speed sensor code and water in fuel code. Don't remember the exact numbers but I can post them tomorrow of it helps. I'm gonna pull the tank because either way it needs to be drained there's way too much water in it.

 

Sounds like fuel related issues. If you haven't already done them, when your in the tank consider doing the Intank modifications Welcome to guzzle's In-tank Hutch Mod Web Page

 

I guess my main question is would water in the fuel make that problem? Or am I looking more at a low fuel pressure problem because the truck gets good fuel pressure haven't hooked a gauge on it yet but probably will tomorrow to make sure

 

I have never experienced Water in fuel scenario so I don't know how it would react. I wouldn't imagine it running very well though.

 

With amount of water you saw in fuel filter are going ruin injectors.

They are picky on fuel quality if dirty or water it will destroy them.

 

Well guys pulled the tank drained it had it cleaned out and took apart the mixing chamber and cleaned out the filters inside and blew through all the lines. Changed the fuel filter and cleaned the housing and out good diesel in it and starts and runs fine now. Thanks for the help. I'm not sure if it was the water in the fuel or the clogged filters in the sending unit or a combination of the both but thanks for the help.