I've taken my truck off the road and have being working evenings and weekends for the past several months doing various maintenance projects to keep the truck running in tip-top shape. This site has been a great resource for information but I think I missed a step during the removal of my injectors.
Right now, all my injectors are wrapped up and ready to be shipped for repair but having thought about it, I didn't number the injectors as I removed them from the truck. I've read through pages of posts in the forums and watched many hours of videos about injector replacement on my particular truck but nowhere did I see a step (at least the posts and vids I watched) to number the injectors during removal. With that said, I have seen images of removed injectors with numbers 1 thru 8 hand written on top of the solenoids. This is where I'm confused.
When I receive my injectors back, is there any particular order I must reinstall them so as not to damage the motor?
Thanks
Dave
2001 F250 Superduty 7.3L
No Mods
335,000 miles and going.

 

Some great replies; gotta make sure I seat my injectors correctly.
Just received my remanufactured injectors back today and they look fantastic; like new parts. I'm chomping at the bit to install them now but I got to wait on the injector cup removal tool from Riff Raff Diesel. Here's how that went...
Truck has over 300,000 miles with no major work done under the hood. There was a dramatic loss of power over the last few months and I thought it was a bad injector issue since power would return after the truck warmed up. I watched a lot of videos and read many tech posts regarding the problem and decided to pull the injectors and have them rebuilt. During removal I noticed the valve cover harness was slightly disconnected from the gasket and remembered the 25 cent repair trick from DieselTechRon. I purchased two new gaskets and harnesses because of the high milage but also decided on new glow plugs while I'm in there. Well, as I'm waiting for the injectors, I watch another injector video on Youtube and come across injector cup inspection procedures. I go get my inspection mirror and waddle my fat *** into position and notice a few hair-line cracks in two of the cups. The coolant looked clear and the resovoir free of oil but I decided to buy new cups from RiffRaff while I'm in there and because of the high milage. To remove the cups, I gotta drain the coolant, so after doing that, I decided to change the water pump since it was making a racket over the last two weeks. I removed the fan shroud, belt and fan to access the pump but one bolt gave me trouble for a few hours. During the removal, I damaged the coolant temperature sensor and had to order a new one. I installed the new pump sans the coolant sensor and gazed into the open space where the fan should sit.
With all them parts off the motor, and while I'm in there, I could easily access the EBP sensor and tube that goes to the exhaust manifold. I removed the EBP sensor and began to work on cleaning the tube to the manifold. I tried doing this procedure without removing the tube by running speedometer cable (like a rooter) through the tube but the cable kept hanging up half way down the tube. I had to remove it for s proper cleaning but during removal, I twisted off and damaged the tube at the manifold and had to order a new one. Glad I done this because the tube was blocked good with crud at the connection to the manifold.
So here I sit hoping the injector cup removal tool comes this week so I can put the motor back together. With that said, does it matter which sequence I reinstall the rebuilt injectors?

 

At this point there is no need to worry about it. Really there is no issue numbering in the first place except for knowing what came from where and putting them back that way just for knowledge sake if problems arise. You should be good to go with tossing those bad boys in.

Just remember to make sure to clean out the bolt holes and use the proper torque. Do not reuse the copper washer at the injector tip if you have to remove for whatever reason. The other o-rings you can reuse if they were not damaged at all. Make sure to lube the heck out of the o-rings before you slide them in the holes when you do install the injectors.

 

The only one a guy needs to know is the #8 injector on some 7.3's.


You should still be able to tell it apart from the others by the two letter designation on the solenoid. I forget all the two letter designations but 7 will be an "AD" or "AB" or the like, the 8th injector will be an "DD" or "AA" or the like.


Basically look at all the letter designations on the injectors. If one doesn't match the others that is your #8 hole injector.

 

Nice catch. I saw the avatar and did not even notice he said 7.3. As stated above, just look for the letter designation and whichever is different from the others will be your #8 injector. #8 will be the driver side toward the rear of the motor closest to the driver in case you do not know that. I always remember by thinking "my passenger is odd".

 

Snowseeker, Thanks for the head's up but I think that may be a problem now and I may have to remove the valve covers again to check. Since I could only work on my truck weekends, the list of maintenance work probably took in excess of five months to complete. Still not finished; it's a labor of love! It seemed the more work I performed, something else would pop up that needed to be fixed. For example, the original glow plug replacement job turned into a set of rebuilt injectors and new injector cup install, new injector/glow-plug valve cover wiring harnesses and gaskets and most important, the fifty-cent harness connector fix. When I buttoned everything back up, I noticed the external valve cover harness connector on passenger side was melted and some of the cables stripped of insulation. I've ordered new harness connector pigtails from Clay at RiffRaff but in the meantime, I patched up the cables as best I can.
So I dropped the truck off the jacks last weekend to take it on an 80-100 mile run to purge the system and I didn't make it 3ft out of my yard when I lost brakes and steering. The big pool of transmission fluid on the driveway was a good indication something wasn't right. Popped the hood and noticed the high pressure power steering line was blown right out of the side of the steering pump. Installed a new pump, pulley and master cylinder and bled the system before taking off for a drive yesterday.
It took six, 12-15 second cranks, resting ten minutes between cranks to cool the starter before the motor finally came back to life. As expected, the engine ran rough for a while and spewed a lot of black smoke in the process but I figured the upcoming drive would alleviate much of this as the system gets purged of air and the like.
During the test drive, I noticed an intermittent knocking sound coming from the driver side of the engine compartment. Since the clacking wasn't there before, I knew it had to be something connected to the injector work I had just performed. I understand there's a number of factors that can contribute to the engine knock and now the unique letter designation for the #8 injector is another possibility to consider. I've gone ahead and ordered OBDlink MX bluetooth scanner and ScanXL Pro software to help diagnose the problem before I slap another wrench on the motor but can anybody out there offer any input about where I should start the diagnostic problem? Here's the possible problem areas:

1) Number 8 injector in wrong hole. (as suggested by Snowseeker
2) IDM going bad.
3) Damaged valve cover harness or connector harness and/or stripped cable.
4) Damaged injector
5) Bad Glow Plug

During the install process, I went through great pains and took my time to make sure every injector cup, injector, and glow plug was pressed-in, sealed, seated correctly and torqued down to OEM specs. Tripled checked that ALL the valve cover harness wiring was latched on and pressed down before installing the valve covers. I installed only Motorcraft and Ford OEM parts so I'm wondering where and how I should start the troubleshooting. Snowseeker, I'll do a little research online about the letter designation of the #8 injector on my truck but if anyone can point my nose in the right direction regarding injector placement on a 2001 f250 7.3 Superduty that would be much appreciated.

Dave