Injectors dropping 1 after another.

Gab · May 15, 2017

Hello, first I want to thanks everybody who regularly share amazing info here. The info I found here helped me a lot in the last few years. Today I am a lost. I got an 11 350 coming in for reduced power about 2 weeks ago. Went on the road and the truck ran good until going up hill at full power then it died and would never restart. No rail pressure. Got it towed back and found injector#5 mechanically stuck open. I replaced inj, #5 witch was cover with carbon from top to bottom and got truck started but ran on 4. Got code for contribution #6. found injector short to itself. replaced injector #6 and got truck started running on 8. drove outside and went to take off but truck died. Restarted on 4. Had code for contribution #3. I could never prove the injector or the harness wrong but everytime I would disconnect it, I would get back on 7. Hotline recommended to replace it anyway and also recommended a fuel system as we have pink fuel. ( farm fuel in northern Canada) I replaced #3 injector and truck started on 8. Went on the road and truck would drive perfect on 8 with good power on moderate throttle. As soon as I would floor it, I would loose a bank and get code for contribution#2. The truck would not restart. At this point I had a mechanical fuel gauge and could verify my low pressure was checking good as well as rail pressure. I went and disconnected #2 and truck re-started on 7. Reconnected #2 and it came back at 8. I took a sample of fuel on the driver's end of the fuel rail and apart from being pink, the was no special smell to the fuel, neither then metal nor rust on the control valve. I decided to drop the tank and flush the system. Having a bigger sample now it appears the it smell like varsol (confirmed by everybody who looked at it.) I put fresh fuel in and flushed the system through the lift pump return line but truck is still acting up dropping bank. I left it idle and lost the other bank (not the one from injector#2. but no codes for this one. As running on 4, if I floor it, it stall and I get a code for injector #2 short to high side and cam position sensor. The gasket tab on the egr cooler is already folded. I think the injectors may just have been damaged from the bad fuel and fail one after another but as my service writer gets chewed by the truck's owner, I though I would take a chance to quiz you guys. Any help would be appreciated event if it it just to say that bad fuel destroy stuff and that I will need a fuel system regardless. Thanks for reading my novel!

tonybullitt · May 15, 2017

My understanding is that some times fuel system contamination can cause the piezoelectric material to crack then it causes them to short. When they short out the pcm failure management shuts down the 4. It will take a fuel system to fix.

tonybullitt · May 16, 2017

From tsb 11-10-10

Some 2011-2012 F-Super Duty vehicles equipped with a 6.7L engine may exhibit diagnostic trouble codes (DTC) P1291 and/or P1292 due to an internally shorted fuel injector. An internal short in a fuel injector may be caused by the fuel being contaminated with diesel exhaust fluid (DEF), or by fuel gelling.

This is interesting from original tsb 11-6-10

Some F-Super Duty vehicles equipped with a 6.7L engine built on or before 5/18/2011 may experience diagnostic trouble code (DTC) P1291 and/or P1292 due to an internally shorted fuel injector. This concern may be caused by gelled diesel fuel restricting the fuel injector return hose. There is a new fuel injector return hose available which will reduce the occurrence of shorted injectors due to fuel gelling

tsb11-10-10.pdf

tonybullitt · May 16, 2017

Here is 11-6-10

I wonder if the newer calibration of pcm is now setting the cyl short code instead of the 1291 or 1292. Also looks like from the tsb just injectors and return hose is all that is needed. Not complete system

tsb11-06-10.pdf