IDI Newbie

[Mattbo]

Hey guys just bought a 93’ 7.3 IDI. Looking for newbie “to dos” before getting deeper into it. Currently runs and drives, but has what seems like a slight miss at idle and driving. Po said he replaced the injectors should I entertain the DieselKleen or Seafoam in the filter bowl overnight and try to run it clean or should I go ahead and pop the IP out and replace it and the lines? I’m familiar with the 7.3 Powerstroke world so have some diesel knowledge, but definitely new to the IDI game. I intend to change all the fluids and start going through everything just wanted to see how I should tackle the main issue it has before getting into everything else.

 

[Nero]

Welcome to Oilburners!
Running any type of fuel cleaner is always a good idea, I usually recommend PowerService since it is usually available everywhere.

Basic things I would check is glow plugs, make sure they're all working, good air filter, and good oil. These are pretty simple engines, not a lot to them.

 

[Mattbo]

Welcome to Oilburners!
Running any type of fuel cleaner is always a good idea, I usually recommend PowerService since it is usually available everywhere.

Basic things I would check is glow plugs, make sure they're all working, good air filter, and good oil. These are pretty simple engines, not a lot to them.

Thanks I am looking forward to doing most everything on it. My 02’ 7.3 not so much so this will be a truck for me to get back tinkering in my free time.

 

[WrenchWhore]

I'd start with the easy stuff like fluids and filters. Diff, transmission, t-case, engine, power steering, brake fluid engine coolant etc. Get coolant test strips to make sure it has the proper amount of SCA's in the coolant. Inspect for all the maintenance that was done or not done. These trucks are old and are known for being run into the ground. As far as the miss goes do the fuel filter full of ATF, seafoam, MMO, or whatever diesel cleaner you can get your hands on. Let that stuff marinate in a warmed up engine overnight to see if it helps your miss/stumble. Don't be overly gentle on her the next day. Give her the beans. If it doesn't change i'd start looking at a fuel line return kit rebuild. Look for fuel leaks anywhere. If you have the return line that goes back to the filter head i'd delete that.

 

[IDIBRONCO]

Po said he replaced the injectors

should I go ahead and pop the IP out and replace it and the lines?

The problem here is that the IP and injectors wear at the same rate. Because of the prices, people only want to replace one or the other and I can perfectly understand that. By doing just one, it's just a temporary fix at best and you will start having issues again. Of course if you know for sure that one of the two were recently replaced with quality parts, then it's OK to just replace the other.
That said, I'd do some playing around and see if you can get your engine running better. In the meantime, just keep in mind that your IP will likely need to be replaced sometime in the not too distant future. I hate telling people to spend money, but it's the best way to go in the long run.

 

[Mattbo]

I'd start with the easy stuff like fluids and filters. Diff, transmission, t-case, engine, power steering, brake fluid engine coolant etc. Get coolant test strips to make sure it has the proper amount of SCA's in the coolant. Inspect for all the maintenance that was done or not done. These trucks are old and are known for being run into the ground. As far as the miss goes do the fuel filter full of ATF, seafoam, MMO, or whatever diesel cleaner you can get your hands on. Let that stuff marinate in a warmed up engine overnight to see if it helps your miss/stumble. Don't be overly gentle on her the next day. Give her the beans. If it doesn't change i'd start looking at a fuel line return kit rebuild. Look for fuel leaks anywhere. If you have the return line that goes back to the filter head i'd delete that.

I appreciate the info that’s kinda what I have been reading and wanted to verify before I do it.

 

[Mattbo]

The problem here is that the IP and injectors wear at the same rate. Because of the prices, people only want to replace one or the other and I can perfectly understand that. By doing just one, it's just a temporary fix at best and you will start having issues again. Of course if you know for sure that one of the two were recently replaced with quality parts, then it's OK to just replace the other.
That said, I'd do some playing around and see if you can get your engine running better. In the meantime, just keep in mind that your IP will likely need to be replaced sometime in the not too distant future. I hate telling people to spend money, but it's the best way to go in the long run.

My thoughts were to try and isolate the pump with an overnight bath and if it ran ok for even a day after the soak I’d replace it knowing I spent $$$ wisely.

 

[franklin2]

If the miss is consistent at idle, you can get the engine idling and then loosen the line on each injector one at a time. When you loosen it and it starts leaking, that cylinder should drop out. You may be able to use this to isolate which cylinder has the miss.

 

[Sparks-IDI]

Welcome from Melbourne, FL Mattbo.
Thought I'd chip in my 2 cents. I had similar issues as you. I just took a little different slant to filling the filter. I pulled the hoses from the mechanical fuel pump and created an IV drip. Had to pull the fuel tank line to prevent the pump from pulling fuel. Then an old bleach bottle with the bottom cut out, a brass fitting screwed into the cap, and hung it up. This way, ATF was completely filling the whole fuel side from filter to injector. See my earlier post.

IDI mechanic San Jose area

Hi All Been lurking for awhile but now have a question. Have a '93 7.3 that was sitting for 3 years due to personal issues. It's not our main vehicle, only used for hauling and towing things around town when needed. Unfortunately my guy is no longer with us so i need to find a mechanic to...

www.oilburners.net

 

[Mattbo]

If the miss is consistent at idle, you can get the engine idling and then loosen the line on each injector one at a time. When you loosen it and it starts leaking, that cylinder should drop out. You may be able to use this to isolate which cylinder has the miss.

Ok I will get it warmed up and check each. I did want to test the injectors and not just rule them out.

 

[Mattbo]

Welcome from Melbourne, FL Mattbo.
Thought I'd chip in my 2 cents. I had similar issues as you. I just took a little different slant to filling the filter. I pulled the hoses from the mechanical fuel pump and created an IV drip. Had to pull the fuel tank line to prevent the pump from pulling fuel. Then an old bleach bottle with the bottom cut out, a brass fitting screwed into the cap, and hung it up. This way, ATF was completely filling the whole fuel side from filter to injector. See my earlier post.

IDI mechanic San Jose area

Hi All Been lurking for awhile but now have a question. Have a '93 7.3 that was sitting for 3 years due to personal issues. It's not our main vehicle, only used for hauling and towing things around town when needed. Unfortunately my guy is no longer with us so i need to find a mechanic to...

www.oilburners.net

I like that idea a lot did you use that just to make sure you filled the entire injection pump? or almost like an IV fuel line treatment with it running I just wanna make sure. I know there are mechanic shops that will do an actual treatment similar to what you’re talking about.

 

[Mattbo]

I went ahead and popped the filter off and filled it with DieselKleen let it soak for an hour or so and cranked it seems to have made a difference so far. The PO was driving this truck daily about a month or so ago then said it developed a miss or stutter so i may just need to replace the pump and lines to be safe. It still stumbles a bit coming off the throttle, but a noticeable difference just from the soak!

 

[Sparks-IDI]

Mattbo,

Yes, I just ran the truck with straight ATF about 2 quarts worth. Engine never changed sound or anything as it transitioned to straight ATF. Ran the 2 quarts until it was almost gone and shut it off and left overnight to soak. So yea, everything filled with ATF for a soak.

 

[Mattbo]

Mattbo,

Yes, I just ran the truck with straight ATF about 2 quarts worth. Engine never changed sound or anything as it transitioned to straight ATF. Ran the 2 quarts until it was almost gone and shut it off and left overnight to soak. So yea, everything filled with ATF for a soak.

Any ATF?

 

[Sparks-IDI]

I would guess any "normal" ATF will work. I used what was left of my Dex/Merc I used for my transmission. I have read accounts where Type F has higher detergent characteristics. Ok, fine. If I had type F laying around I would use it. It's just a couple of quarts for maybe 20 minutes of running time to do this flush. The new ATF's don't have as much detergent agents as years ago as I understand it. I did follow up by filling my tank and used the max amount of Diesel Kleen that their label specifies. That was maybe a couple months ago I did this and the truck is running just fine.