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Discussion Starter · #1 ·
First time posting, long time reading. I have searched through this forum and any others I can get my eyes on and if my issue has been addressed before, forgive me but I can't find it.

Late 1999 F250 7.3 no mods except tuner. 175,000 miles.
Noticed at idle it had a slight knocking sound that was abnormal but that went away with rpm. Drove home about 40 miles and it drove fine but when I got home I noticed a slight raw fuel smell from the exhaust when I got out after shutting if off.
The next day it started but was stumbling and running really bad.
Now it doesn't start but wants to. Once in every couple tries it will start but shake bad.

-Ran buzz test. Passes. Crisp and even sound. Tach jumps to 3000 when all 8 buzz and to 2000 when each individual injector buzzes.
-No DTC's/no CEL.
-While it was running I disconnected the pass side UVCH and it didn't change much at all except for a slight buzzing when reconnected. When I disconnected driver side connector engine shut right down. Indicating only driver side seems to be firing.
-Ran cylinder contribution test. Indicated cylinders 1, 3, 5 consistently. Sometimes 7 with them.
-Performed resistance test from IDM connector. All injectors between 2.9 and 3 Ohms.
-Swapped CPS with known good. OEM Motorcraft.
-Swapped IDM with known good.
-Pulled ICP connector. No change in symptoms.
-Pulled all tunes and put back to stock. No change.
-Fuel pressure appears good. Replaced fuel filter just in case it was it. Fuel filter looked fine and fuel in bowl was clean.

Next plan was to pull the passenger valve cover and disconnect one injector at a time to see if an injector is taking down the whole bank. I read somewhere someone had that. Also will visually inspect for a bent pushrod etc. becasue I also read that one persone had a bent rod and it caused the whole bank to fail. Not sure how that works.
Just hoping someone else may have seen this.
Scouring the forums I did find instance where a guy had the same thing and he eventually replaced all 4 injectors on that side.
I know these are not original injectors. PO replaced them a few years ago. PO was a diesel mechanic and took care of engine meticulously. I just don't see how multiple injectors failed at the same time. I can't see how it is electrical but this is my first diesel. Been working on gasoline engines for 30 years so the concepts are clear to me, just don't have experience.
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