I have 2000 f250 7.3. I've replaced fuel injectors, glow plugs, fuel pump, wiring harness, fuel bowl, icp, and other sensors but it still runs rough at low rpm, has a popping sound at exhaust,I I hear a knock until I increase rpm, loss of power, surges when slowing down. I can't figure this out. Not getting any codes either, no check engine indicator.

 

Checked fuel pressure?

 

Fuel tank level?

 

What are you using to pull codes?
Did you use OEM Motorcraft or International sensors and control to include the valve cover gaskets and harness, items form the Ford or International dealer counter? If you ordered through Fleabay, Cramazon, the corner part store, and almost every other online place, just save everyone and yourself troubleshooting issues and do it again properly.
You had many fuel and oil components open, did you drive safely but aggressively for about 100 or so miles to purge the systems back out?
Do you have clean, fresh, proper level, proper type turbo diesel oil?
Do you have at least 1/4 tank of fuel or more of good fuel? See Hutch/ Harpoon Mod for more information.
Have you checked your fuel filter for contamination?
Where did you get your glow plugs? See OEM only comment.
Where did you get your injectors? Way too much garbage out there.
Have you used the proper fuel filter and cap?
Have you checked your HPOP reservoir to insure it is full?
Have you checked your transmission fluid when hot to insure it is the proper level if an auto???

Lastly we need more information about your truck such as configuration, miles, modifications. The more you give us the better off all will be with assisting you.

 

Popping sound at idle? Not a good sign. Is the sound coming out of the tail pipe or the intake, or from under the valve cover? Let us know that information and we can get a better picture for what to tell you next.

 

Think we already lost the her...
Such is life I guess.

 

You haven't lost me, I have been extremely busy at work, I need to take all your questions to my husband and have a conversation with him about more of the details you have mentioned. I know we have learned from past experience that OEM parts are the best choice and most of what we have ordered online has been from Prosource Diesel, Thoroughbred Diesel, Xtreme Diesel and Ford Dealership and local parts stores. We have over 400000 miles on the truck I know my husband has changed fuel pump and drained the tank, cleaned and replaced some of the screens he found that weren't looking good. The glow plugs were given to use when we purchased the truck with the receipt where the gentleman purchased them from local dealership (he just didn't get them changed before we decided to buy the truck). We bought the injectors from Injectors Direct (which is the main thing I am afraid of at this point). I know my husband had to replace some of the parts dealing with the turbo which is a Garrett. My husband changed the 3" air intake and exhaust to 4" and replaced the compressor wheel and wastegate. Our goal is not to upgrade but to maintain and have it run as it should and did when we bought it 5 years ago when we bought it and our fifth wheel and traveled to California from Nebraska and now back in Nebraska. Just getting frustrated that this last issue has been the most difficult to figure out. The codes he had gotten in the beginning were from the CTS tuner we bought right before we took our trip. Also, replaced the PCM and had it flashed at the Ford dealership locally. Any other details I will have to ask my husband about. I joined this group because during the vast amounts of research we've done, this forum and all the advice sharing has helped many times in the past (BTW research is my fav thing, it was my year and half of research of the best trucks to pull trailers that led us to the decision to look for the Ford 7.3 diesel, a decision I still stand by so we have to figure this crap out!)

 

The folks around here will help get y’all fixed up. It just takes a little time to work through and communicate all the items.

I image the first thing everyone will want is some good data. FORScan won’t be able to show fuel pressure (not a PCM item) but it can do many things. It will allow some tests like checking perdels, CCT, and buzz test. I’m not familiar with them myself but have read other posts and feel this might help diagnose a possible injector issue. It doesn’t cost much to get a dongle and FORScan for your phone or PC. Here’s a quote from our resident expert BWST from another recent thread. Reason I’m quoting is because he mentions which dongles seem to work best.

Quoted from here. Quote Source
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Theres an entire section dedicated to FORScan in the sticky tech folder at the top of our forum. Tech Folder Link

Also in the Tech folder is an “easy method” of checking the fuel pressure. Knowing the fuel pressure will be vital information as you’ve already seen a couple other members mention it. Fuel Pressure Test Link

 

1. Lots of possibilities as to cause. Sticking IPR? Low compression causing a misfire? Worn out or badly rebuilt fuel injectors?
2. This one bothers me the most. All of the possible causes that come to my mind involve some sort of internal mechanical engine failure.
3. Engine knocking sounds as far as I can remember (40 years as auto repair technician) always involve something outside of design tolerance for whatever the cause. Again,