2001 7.3 F-350
4WD, Crew cab, dual rear wheels198,000 miles

Hi All,

I recently did the injector O-rings and tune up kit (shims) and now having some problems. I was getting an occasional knock and black fuel in bowl- so I knew I had at least bad o-rings. I went ahead and did the shims while they were out (probably should not have through). Drained the oil from the plugs before removing injectors, vacuumed out through the glow plug holes, and turn it over my hand with glow plugs out- so I know I got the majority of the oil out. After re-installing, the truck had a real hard time starting which was expected. But when it finally did start- it ran really bad like it was only running on a few cylinders at first, but then eventually started to idle. At this point, I did not drive it until the next day.

Next day- it struggled to start again, running on what seemed to be a few cylinders. I unplugged the ICP and it started right away. I let it run for about 5 minutes, shut off, plugged ICP back in and restarted. This time it started decent. Took it for a short drive thinking I need to get the air out of the system. It idles OK- but has no power after that. It can barely go fast enough to get out of 1st gear.

I checked all electrical connections and they are OK. I also did the buzz test and they all work although some seem weak.

I thought about the IPR valve, but I think it was unlikely since the truck ran OK before doing this work. Does the fact that it starts right away with the ICP disconnected lead to a bad IPR- or ICP itself? The longer it ran without the ICP- the worse it seemed to idle (more knocking) especially if you put it in gear. Since the truck ran OK before I did this work- common sense leads me to believe that I must have done something wrong. It seems like its not building enough pressure on at least some of the injectors.

Any advice on what to check next? The truck probably does need a whole new set of injectors, one was replaced probably 10 years ago- but the other 7 looked original. I figured I would try this since I would only be out $130.00 if it made no difference, but in fact made things worse (go figure). Just want to eliminate everything before dropping $ on injectors.

 

Were the injector hold down bolts torque to spec? How about those rail plugs, you sure they're snug? The first few(3-6) start ups will have some long cranks so it doesn't sound to abnormal on that front. The poor performance could be the shim job I suppose. If it's safe to do so, I'd drive it to see if anything improves. Usually takes 50+ miles to purge the hpo system, especially after pulling all 8.

 

Did you swap nozzles+springs,internal orings etc..?
If not,your injector job was a waste of time.

 

No just the shims- agreed it was a waste of time- but do you think it could actually be causing the issue? Had I wanted to go through the whole injector I would just replace them outright which I probably will do anyways

 

yes all to spec- i was aware if the air being in the lines, but the way it's running seems unusual based on others' experience doing the same job

 

I get springs and internal o-rings, but why would you replace a nozzle unless there was actual damage to it?

Shim kit that includes the internal o-rings and springs is ~$200, new nozzles adds like $4-700. You are half way or better to new injectors from BPD. Kind of defeats the purpose of shimming and diy "rebuild". I'm not claiming that is as good as BPD rebuilt with new nozzles, but it fills its purpose.

 

What injectors are recommended for stock replacement?

 

If you are looking for new Alliant go to https://bitterrootdiesel.com/ or https://www.riffraffdiesel.com/99-03-super-duty-7-3l/

If you are looking for remanufactured go to https://bitterrootdiesel.com/ or https://www.rosewooddieselshop.com/

Each of these shops are site sponsors and active on the forums. In addition, they are the most reputable shops and will stand behind, in front and beside their products and services.

 

140cc ADs for stock.

I paid 227€/257$ for a set of 80% nozzles,1.5 years ago.
Directly from manufacturer,i prefer to skip the vendors.

ICP sensor unplugged idle is sharper,PCM defaults ICP to 725psi(called value) when unplugged.

Higher ICP can mask injector wear/faults.

 

That sounds like a great price 1.5 years ago. I don't know about the manufacturer, but the best price I can find online is Bitterroot at $400 for a set. It quickly goes up from there.

That still doesn't explain the why though.

 

What's your fuel pressure post filter?

 

Fuel pressure is 57 psi. I have a gauge in the truck and it was steady

 

Are the armature plates orientated correctly to the solenoids?

 

Fairly certain they were, but I am going to tear it down again tomorrow and check before they are removed again completely

 

Do you want to take a look at your ICP and IPR% with FORScan before you take it apart again? Any codes with the buzz test, or codes in general? Alot of things are moved around when injectors are pulled, so not unusual for something else to have failed like an UVCH, ICP or IPR, or related wiring, as a result.

Agree certainly with looking at the last thing you worked on. If I had a black fuel filter, I'd be leaning toward an o-ring change as well. I'm nervous about tackling the shimming though given experiences like this. So far, 5W-40 synthetic oil is taking care of cold start issues caused by my worn injectors.

Could a Cylinder Contribution Test help you focus on the specific injectors that are not functioning?