2000 F-350 tow truck with recurring P0270 & P1274

[mchan68]

I got one here with the two DTCs listed in the thread title. When vehicle first came in, it also flagged those two DTCs on the buzz test. Injector #4 sounded faint compared to the other seven. Replaced injector and reran self-test. Engine ran smooth and DTCs didn't return.........until today. Also showing a P1316 in memory. An IDM wouldn't cause this would it? This is one of those moments I'm wishing I had a tester IDM to play with. Unit has 745,000 kms. Truck looks clean under the hood, like it's been maintained well. UVC wiring looked good when I had the valve cover off.

[Aaron]

Come to Windsor this weekend and borrow my known good IDM.

[Shlep]

Come to Windsor this weekend and borrow my known good IDM.

 

Weren't we just talking about that yesterday?

[Aaron]

No kidding.

[Alex Bruene]

2 years ago, after a massive weekend of rain, an ambulance fleet we service had 3 IDMs go down on the same weekend. They then decided to replace the IDMs on the rest of the fleet (about 10), and let us keep the old ones... nice, eh? So everybody now has a tester...

 

Now that I've got that out of the way, an IDM can cause that. Alot of the time, a visual inspection of the IDM, along with a good sniff can give an idea of the condition it is in.

[Keith Browning]

I am not sure a "sniff" is going to get you anywhere but when it comes to the E-series IDM's gust give them a good shake. Usually, if there is a problem it is related to water intrusion and you can hear the water inside.

[Bruce Amacker]

I am not sure a "sniff" is going to get you anywhere but when it comes to the E-series IDM's gust give them a good shake. Usually, if there is a problem it is related to water intrusion and you can hear the water inside.

Or pull the cover off and see the moisture corrosion inside.

 

 

[mchan68]

Well, I had our parts manager order an IDM in for stock. Plugged it in, and low and behold it still flags a hard P0270 when running a KOEO injector buzz test. I have double checked and triple checked wiring between the IDM connector pin #7 and the connector at the VC. I even checked cylinder #2 circuit white wire between pin #22 on the IDM and the VC connector with the exact same fucking readings. Funny thing is, this truck now won't start!!! I checked fuel pressure and quality. Both are good. The truck will fire up initially, but won't stay running. ICP volts and pressure are well within specs. I even tried a known good CMP just for shits and giggles (that's what the customer blames it on). Same fucking thing!!! What next?

[LARRY BRUDZYNSKI]

 

No just kidding...Have you put back the IDM? I think you need to have a break, cup of coffee and a smoke and start from scratch. It sounds like you missed something....Are the codes constantly coming up active or intermittent?

[Shlep]

Mike, I had like this awhile back and it ended up being a shorted injector...even though it tested good with a meter, kinda had me running in circles just like you seem to be now. I ended up unpluging the suspect injector and retesting it to make sure it "seen" the open just to be sure I wasn't overlooking something.

[mchan68]

Mike, I had like this awhile back and it ended up being a shorted injector...even though it tested good with a meter, kinda had me running in circles just like you seem to be now. I ended up unpluging the suspect injector and retesting it to make sure it "seen" the open just to be sure I wasn't overlooking something.

And what are the chances of having a bad-out-of-box injector? I swear this thing was running smooth after I replaced the injector initially. I road-tested it around the block a couple of times even letting it idle for a bit. I even cold-started it the next day before it was picked up with no problems. The customer says when he picked it up, it started to run rough again, to the point it where it wouldn't start. What bothers me most, is EVEN IF one cylinder is down, it should still be able to fire up shouldn't it?

[Shlep]

As strange as it seems it was a new out of the box injector that was setting the code... it was about 3 weeks old, thats why it was confusing the hell outta me, and it did stop the engine from starting... for no reason that I could make any sense of, who knows anymore.

[mchan68]

As strange as it seems it was a new out of the box injector that was setting the code... it was about 3 weeks old, thats why it was confusing the hell outta me, and it did stop the engine from starting... for no reason that I could make any sense of, who knows anymore.

My concern is what happens if I replace another injector and get the same fucking thing happening again? Do I claim all the 6005 series labour ops along with the 9527AL under the SPW?

[Shlep]

That I can't tell you, but what I would do in this case if you still have the cover off is lay another injector down there and plug it in and run the buzz test to see what the results are.

[Bruce Amacker]

That I can't tell you, but what I would do in this case if you still have the cover off is lay another injector down there and plug it in and run the buzz test to see what the results are.

This would be my exact move.

 

Quote:

And what are the chances of having a bad-out-of-box injector?

Really good. I've seen MANY bad injectors out of the box, especially remans. This is why I promote Alliant Power injectors- almost zero defect rate.

 

Swap the injector feeds from cylinder to cylinder and re-run the buzz test. See if your code stays with an injector or moves with the harness. Sometimes the UVC injector feeds can be swapped in place, or lift the VC gasket, rotate it end-to-end 180 degrees, lay it back down, plug in the injectors (into the wrong injectors) and run the buzz test. Don't try to start it this way, obviously.

 

Good Luck!

 

[mchan68]

Well, here's what I've so far. I've swapped the IDM with a new one ordered in for stock. Same DTCs. I've load tested the circuit on the high and low side by plugging in a headlamp bulb on the injector side of the harness, and a spare 12 volt battery at the IDM side of the harness. Bulb lights up nice and bright. I even powered it up through cylinder #2 side of the circuit with same results. I've flipped with VC 180 degrees as per Hotline instruction with the same results achieved. I've plugged in another new out-of-box injector (without actually installing it into its bore) with the same results. I've OVERLAYED circuit #558 (BN/LB) cylinder #4 low side straight from the IDM to the VC. SAME FUCKING THING!!! I've checked and double checked the UVC harness (even plugged a new one in with the SAME FUCKING THING!!!). What to do next!!!!

[Shlep]

Delete your IDS session and start over with the UVC harness flipped over and see what you get.

[mchan68]

Delete your IDS session and start over with the UVC harness flipped over and see what you get.

Tried that already. SAME FUCKING THING!!! Here's a good one. Hotline's next instruction is to put a new engine harness in it, despite the fact that I verified and verified and reverified the circuit(s) are good!!!

[LARRY BRUDZYNSKI]

Mike, I have been checking this out all day and keep coming up with 1 of 2 things possible. Either the Engine harness needs to be replaced or you may have either a bent or loose pin somewhere, we have had customers accidentally bend over a pin on the pass thru on the vcg's. No moisture intrusion anywhere in the connectors?

[mchan68]

UPDATE: I have substituted BOTH the power wire (PK/Y) and ground wire (BN/LB) at the IDM connector and reran buzz test with the wires connected directly to an out-of-box injector BOTH from the IDM in-vehicle and out-of-box IDM. SAME FUCKING THING!!! P0270/P1274 doesn't go away. The injector out-of-box buzzes nice and strong. I don't know where else to go from here

[Bruce Amacker]

Wow, this is a tough one. Some ideas come to mind, and all are far fetched:

 

1. Ohm out all 8 injector circuits at the IDM plug to verify they all have the same resistance. Perhaps the IDM/PCM is seeing an injector circuit problem but misidentifying the injector it is on.

 

2. Do you have an amp clamp or low current probe that you can scope these circuits on? I'd compare the waveforms of each injector during the buzz test and idling to determine if one circuit is looking screwier than the rest.

 

3. A harness problem is an obvious possibility. If there is voltage/RFI/EMI bleeding from one circuit into the #4 circuit, the IDM/PCM could be upset by this voltage and setting a code. I have seen 4 different trucks where the primary wire vinyl insulation became conductive over time and caused REALLY weird symptoms by bleeding voltage from one circuit into another. I was able to positively identify these circuits. This is why sometimes you'll replace a harness that "looks" good but solves the problem. I'd scope all of the injector voltages and look for stray signals. Beware if you do this, the 110VDC or so you're dealing with may be higher than your scope allows and you could need a 10-1 attenuator, which reduces the voltage by 90% so it won't hurt the scope.

 

If I think of something else I'll post it.

 

Good Luck, man.

 

[Shlep]

Bleeding voltage may be possible but Mike's overlayed both circuits direct from the IDM to the injector which to me rules that out.

[Bruce Amacker]

I agree in your theory, but I feel that the IDM/PCM could be confused and setting the wrong DTC. The circuit has been proven perfect with the overlay and is still setting the code. You've never seen the PCM set the wrong code before?

 

 

[mchan68]

Originally Posted By: Shlep

That I can't tell you, but what I would do in this case if you still have the cover off is lay another injector down there and plug it in and run the buzz test to see what the results are.

This would be my exact move.

 

Quote:

And what are the chances of having a bad-out-of-box injector?

Really good. I've seen MANY bad injectors out of the box, especially remans. This is why I promote Alliant Power injectors- almost zero defect rate.

 

 

...and this (in the photo below) wouldn't happen to be the manufacturer you speak of, would it by any chance?

Just an update to this mess. Hotline still insists on a wiring issue being the cause of the problem. In one of my many strolls through the parts department I came across two 7.3L injector core returns. One was the original injector I replaced on the vehicle in question. The second one, is a core return from an outside parts sale. Just for shits and giggles, I borrowed the two cores and reran the buzz test. The original injector I replaced failed (no surprise). Connect the core return (illustrated above) from the outside sale, and what do you know? It passes. After much back and forth consultation between myself, my shop foreskin, Hotline and my SM, I was able to convince my parts department to pick up yet another injector and retest. I guess the third time is the charm!!! I'm driving this thing home tonight and I'll report my findings in the morning.

[Shlep]

Perfect... glad to see something good happened today. I almost thought you either gave up on it or took the day off