[bryank.99]

My dad bought a 2013 f350 6.7 with 190,000 miles. The seller noted that the head gaskets were blown and that there was possible fuel injector failure. Just replaced head gaskets and put head studs on it. The truck started and ran fine prior to the work except for the combustion gases leaking into the coolant... Anyway, followed ford workshop manual as closely as I could for the whole procedure (cab off). I got it all back together and cycled the key 10 times and it would crank but not start. The scan tool showed code P2291. Fuel pressure would not build above 146 psi. Checked it out and found the line from the high pressure pump had not been torqued down. Torqued it down and still nothing. Pulled the fuel volume control sensor and the fuel pump was clean as a whistle inside. Not a visible speck of contamination or metal. Checked the sensor's internal actuation by a process I found in another discussion and determined it was not actuating correctly. Replaced the sensor and reprimed the system. Also installed new motorcraft batteries. The old ones were about six years old and pretty corroded. Still would crank but not build adequate pressure. Hit it with one quick shot of either and it fired and ran for about 10 seconds then died. Cycled the key again and cranked it over and it fired again after about five seconds of cranking and then died shortly after. I tired it five more times with the same symptoms. Put the scanner back on and show three codes, P1291, P1292 and TCM intermittent something or other, can't remember exactly. P1291 and P1292 are for injector short to ground on both banks so I removed the clips from each injector and tested each injector for continuity to ground and I didn't find anything. I carefully visually inspected the wiring harness from the PCM to each injector checking for chafes and breaks and didn't find anything.

I have not checked the resistance of each injector or the return volume. I have not tested for proper voltage at PCM terminal and I have not tested wire continuity from the PCM connector to each injector. I have a new fuel filter to put on the rail, but I ran out of time this week to do anything else.

This project is starting to stump me and I am looking for advice on things to check. Is this looking like multiple injector failure or aeration or something like that? I'm running out of ideas. I'm planning to do a resistance check on each injector next.

Here is a youtube link to a video of the start up symptom: 2013 6.7 PSD starts then dies after major work Codes P1291, P1292

Other notes: egr and dpf are deleted.

Also an interesting note is that this harbor freight scanner shows the PCM's top recorded speed to be 158 mph. I find that pretty incredible on a truck like this. Not sure I believe it. No wonder the head gaskets were blown.

 

[matthewd11]

You need to do some more troubleshooting. Verify the low side is completely air free. Check over the injector wiring carefully. Measuring the fuel returns for the injectors would not be a bad idea.

have you tried keeping the throttle to the floor to keep it running?

 

[bryank.99]

I haven't tried keeping the throttle on the floor. I won't work on the truck again until Monday. What's your best advice on identifying and isolating an air leak on the low pressure side? I pulled the yellow fitting off of the engine mounted filter and with KOEO it pumped a 12 oz cup full in just a few seconds. The connector assembly from the rail to the engine with the two hoses with the yellow and the blue quick connects is new because the blue quick connect was damaged slightly during reassembly.

As far as testing return volume from the injectors, my understanding is remove the electrical connector and return line. Then cap the return line and measure the output volume during a 15 second cranking duration. If output volume is greater than 3 mL the injector is suspect. Can someone verify this?

I will try and post the wiring diagram that I will use to check out the injector harness in hopes it can be of use to someone else.

I also forgot to mention that without a doubt each injector was returned to its original cylinder, so I am not suspecting IQA problems.

 

[bryank.99]

 

[bryank.99]

Today I replaced the fuel filters. I tried keeping the throttle to the floor to keep it running, but it didn't make a difference. My brother suggested that if there was an air leak on the low side we would be able to tell if we pressurized the tank as the pressure in the tank would counter act the air leak in the line. So we tried that and it did run for just a second longer. Now it shows two additional codes. P060A Internal Control Module Monitoring Processor Performance and P1201 Cylinder 1 Injector Circuit Open/Shorted.

I began the pinpoint tests for fuel injectors for each injector. I made it to P5 which prompts to test resistance between each pin of the harness side of the injector connector and ground to verify resistance is over 10k ohms. The power pin on each connector is about 0.45M ohms which is fine but I get no reading for continuity on the ground pin for each connector. Is this my problem maybe?

 

[matthewd11]

You want no continuity or very high resistance to ground. Ground is controlled through the ECM. You’re just checking the wiring for short to ground outside of the ECM in that test. It’s possible you have an internal short to ground when that injector driver is energized in the ECM (stuck energized). It’s possible you may have an ECM issue with that internal error DTC and that injector circuit code.

Just a note but the fuel pressure never drops right off from the desired in your video, I’m not convinced that is why it’s stalling.

Did you test all the wiring from the injectors to the ECM?

Unplug cyl 1 injector and see if it starts. I doubt it will but worth a try

 

[bryank.99]

Yeah, when I saw that code, I kinda worried it might be the PCM. I'll have to do a few more tests tomorrow. If it's indeed bad, what could cause it to fail like this? It seemed to function just fine before the work. I always take care to disconnect the batteries before I make or remove a connection from a PCM.

I have checked the internal resistance of the injectors, checked for injector short to case and checked for 0 resistance on each wire in the injector harness. I feel like I found a hack for checking the internal resistance of these injectors but maybe everyone does it this way and I was the one in the dark.

Instead of disconnecting the electrical connector from the injector and trying to weasel both probes of the multimeter down onto the electrical pins on the injector, disconnect the battery and pull the middle connector out of the PCM and you now have a giant jumper wire with easy access to all eight injectors via the bottom row of pins! I'll try and attach a copy of the pinout.

 

[bryank.99]

Unplugged cylinder 1 injector and it started and ran the same. Got two more codes one for cylinder 4 injector and one for cylinder 8 injector and the code for cylinder one went away with it unplugged. With cylinders 1 and 8 injectors unplugged it still starts and runs just like the video. Today I will continue with on with the next injector pinpoint tests and also try to rule out air in the injector return lines.

 

[bryank.99]

Made it through pinpoint p6 and all eight injector connectors registered about 0.4V on the power pin with KOEO. I think that points me to the PCM which we already suspected. Spoke to a shop that I deal with sometimes and they agreed PCM is the prime suspect. I have an appointment day after tomorrow they are going to put a used one in and program it for me. I’ll post with an update after.

 

[bryank.99]

The shop programmed in a known good PCM today. Unfortunately, it didn't fix the issue. Same symptoms were present except while it was there it never ran long enough for the starter to disengage which he said meant that it didn't give him the run time he needed with IDS to get very much meaningful injector data. The man was kind enough to reprogram my old PCM back in and only charge me for an hour of his time. He has worked on ford diesels everyday for close to 40 years which has got to be about as long as they have been around. He was working me into schedule this morning and didn't have a lot of time to look at it with me but he looked at the codes and listened to it and offered me some free advice which I appreciated and will share here. I guess his ears are pretty trained at this point. He told me that it sounds like it's only hitting on three and sometimes four injectors and that I should go back to the injector pinpoint tests with the assumption that the PCM is good. He also said that sometimes injectors that short out on the 6.7 sometimes give a resistance reading that falls within spec while the engine is off and to check them again with the engine cranking or running if it will start. He told me that with the P1291 and P1292 codes if I go through my tests and find more than one bad injector to replace them all or I'll be chasing bad injectors every 50 miles until they're all replaced anyways. He told me a story from when he was newer to the 6.7 he had a truck come in with one of the bank short to ground codes and a code for one injector. He replaced the injector and 70 miles down the road the customer lost a different injector. They brought it back and he replaced the bad one and sent him off again. He was back after 50 miles with another down injector (different injector each time). He replaced that one and it was back after about the same miles. At this point he just replaced the rest of the injectors and the truck ran fine after that. He also had a injector electrical connector laying around that he let me buy. I soldered some longer wires on it and now I have a good jumper for testing injectors.

First, I checked the resistance while cranking for cylinders 1, 4, and 8 since I had gotten codes for them. All three fell out of spec (150-210k ohms) while cranking. Each time I found an injector that didn't meet spec while cranking I left it unplugged. With each one unplugged, it runs a little better. With those three unplugged it runs for approximately 10 seconds before it dies which is quite a bit longer than in the video. It runs for just long enough for you to start to wonder if it won't die and then it dies. I went ahead and finished the pinpoint test like he told me to and guidance at the end of that for me is to replace all eight injectors if codes P1291 and P1292 are present. So given that and what I found this afternoon with those three injectors and the advice I was given today at the shop, the plan is to replace all eight injectors. They will be in in the morning but I probably won't have time to work on it until Monday. I will update when I can though.

As for why they are turning up bad after the work I guess it is easiest to suspect that they were handled improperly while they were out of the motor. That's not the nicest thought to consider as that finger points directly back at myself. Live and learn I guess. Expensive mistake if that is the case. Are they super delicate? We tried to be very careful with them keeping them clean and each one got its own sealed bag when they came out. Going back in we followed the book to a T. The guy at the shop said that they are super sensitive to moisture. Even a little bit of condensation on them while they're out could be enough to cause problems.

If this thing starts and runs after replacing the injectors, is it ok to drive it into town to have the IQA codes programmed in or would it be better to trailer it?

 

[bryank.99]

Put eight injectors in and it fired right up. Runs rough as expected until IQAs are programmed in. The hold down bolt for injector 5 broke off when I was taking the old injector out and that was a pain to make right. In case anyone is curious, I pulled the valve cover and just used a screw extractor from the hardware store. I put magnets around the hole to catch metal flakes from the drilling. Saw that there's like a $500 kit to get those out but the simple screw extractor worked great for me.

On the first crank after its been sitting a minute it cranks for about five full seconds before it fires which I would consider a little abnormal. I'll have my connector tomorrow to get set up with forscan and I'll look into that a little more if it's still an issue after I program the IQAs.

 

[matthewd11]

Put eight injectors in and it fired right up. Runs rough as expected until IQAs are programmed in. The hold down bolt for injector 5 broke off when I was taking the old injector out and that was a pain to make right. In case anyone is curious, I pulled the valve cover and just used a screw extractor from the hardware store. I put magnets around the hole to catch metal flakes from the drilling. Saw that there's like a $500 kit to get those out but the simple screw extractor worked great for me.

On the first crank after its been sitting a minute it cranks for about five full seconds before it fires which I would consider a little abnormal. I'll have my connector tomorrow to get set up with forscan and I'll look into that a little more if it's still an issue after I program the IQAs.

You need to drive it on the highway to bleed the high side completely. Your starting time is normal if you haven’t done that.

FYI most snap on scanners will program IQA codes if that’s what you’re using.

Glad to hear you got it fixed and thanks for the update.