p1690 Can't find what's wrong

[David454]

I've got an 01 6 speed HO with 160k on it I bought not too long ago. Previous owner had installed a FASS and Edge Juice on it. I went to clean up some line routing/wiring and noticed what I now know to be the timing solenoid wires were completely bare at the top outside the sheath. I poked around that area a bit, looked over some fuel pump wiring/hoses and then quit for the night after I saw how much work I needed to do. 

 

Next day I fired it up (still hadn't done anything but literally poke the wire bundle around to look at it)  idling rough, p1690 pops up (no other codes) I shut it down and decided to swap the crank sensor. No change with the new crank sensor, so I went through the rest of the diagnostics I had found on here with no luck. All wiring to the ECM and Cam sensor is sound. All wiring from the vp is sound, grounds are good (less than 1 ohm on my volt meter). I don't know how to check the AC noise from the lift pump but I have a FASS so I would hope it's fine. 

 

I decided to look more at the bare wires for the timing solenoid I had poked, found that there was no evidence of ever having insulation on them (I found other pics of similar situations that seemed like they came factory like that). I wrapped them in electrical tape the best I could, started it up and wala, no codes and idling well. 5 min into the drive I heard the timing change and the CEL popped back up, no power of course, with the same one code p1690. Back to the way it was. 

 

I figured my electric tape job might have been the fix but just not done well enough, so I redid that with some liquid tape added too, and this time only got a minute or two into the drive before the issue came back. Also during this process I tried unhooking the alternator and didn't notice any difference. Tried letting it get back completely cooled off without touching the tape and still having issues so I'm not convinced it is engine temp related. 

 

Only other pertinent information I can think of is that it got below zero here last week and I'm sure the fuel gelled, but I didn't drive it until the temps were over 40 degrees. It always showed good fuel pressure (13+) and made an hour round trip the day before the issue started without a problem. Could the fuel gelling cause pump issues inside it or some residual wax floating around cause issues even after over on hour of trouble free run time since temps were below freezing?

 

Do yal have any other ideas on what this could be? Truck is undrivable at this point. 

 

[Mopar1973Man]

Edited February 27, 2021 by Mopar1973Man

[David454]

I've done everything on the diagnostic guide but #1, and I have a FASS and don't understand how to measure AC voltage across a plug when the truck needs to be running to do so. 

 

I unhooked the alternator and nothing changed, so shouldn't that remove the AC voltage issue from the alternator? 

[Tractorman]

10 hours ago, David454 said:

I went to clean up some line routing/wiring and noticed what I now know to be the timing solenoid wires were completely bare at the top outside the sheath

 

Could you post a photo of the specific location you are referring to?

 

- John

[David454]

The blue traced wires are what I'm referring to. 

[Tractorman]

So, are you saying  the individual wires are showing bare copper?  Or, are you saying the individual wires are still insulated, but the sheathing doesn't quite extend to the end?

 

- John

[David454]

Sheathing was halfway gone, wires showed no signs of ever being individually insulated and had bare wire showing wherever the sheath wasn't. 

 

This morning I took some aluminum foil, folded it up in about 5 layers, wrapped it in electrical tape, and made a sheathing for those two wires then grounded the sheath. I've driven about an hour and a half this afternoon and the problem hasn't come back. Those two wires aren't in a bundle with other wires but are next to the vp's computer. Makes me think there is some kind of electrical noise coming off the pump that the original sheath was supposed to shield from (more than electrical tape could do). When I poked them originally (cause I couldn't believe my eyes that there were bare wires hanging out),  it might have pulled down the sheathing just enough to expose the wires to noise and start the issue. 

 

My first attempt to fix it was by cutting off the excess sheath that had ripped and wrapping it in electrical tape. I think in that case enough of the original sheath was gone that no matter how well taped they were it needed a real noise isolating sheath.  Who knows, the way things are going, the next time I start it up I might be right back where I started. 

[Dieselfuture]

The 2 wires going to vp module are stainless steel, the ac noise is measured at alternator with good quality vac meter at alternator stud not batteries or any pumps. Sounds like dirty connection are at work with some potential ac interference

[David454]

1 hour ago, Dieselfuture said:

The 2 wires going to vp module are stainless steel, the ac noise is measured at alternator with good quality vac meter at alternator stud not batteries or any pumps. Sounds like dirty connection are at work with some potential ac interference

Them being stainless would make sense, definitely didn't look copper.  Resistance to ground was less than 1 ohm from any plug I tested, I used dielectric grease on all the connections when I plugged them back in. I had tried 4-5 other things that I didn't include in the post trying to fix it and nothing changed anything till I started adding more insulation to those two wires. Seems like to me the OEM sheath I cut off trying to find the end of bare wire was important after all. 

 

I tried to measure the AC noise from the alternator post to pass side ground on the battery and my volt meter isn't fancy enough to show anything. 

 

If it is AC noise in the system is there anything I need to do about it if the truck is running fine now? I guess I need to get ahold of a good volt meter and check it if so. 

[Great work!]

Unfortunately the wires going to the timing and injection solenoids will deteriorate they are aviation grade wire with teflon insulation but they still go bad. The timing solenoid likes to go bare right were it enters. it's at the bottom and very hard to get at. You can try heat shrink or liquid tape gasket RTV will work too.  Be careful if the injection wires short together very long it will kill the electronics on top of the vp. See picture.

[Tractorman]

6 hours ago, David454 said:

Sheathing was halfway gone, wires showed no signs of ever being individually insulated and had bare wire showing wherever the sheath wasn't

 

 Thanks for the clarification.  I will have to check these wires on my truck.  I hope you have fixed the problem.  Keep us posted.

 

- John

[David454]

Well after approx an hour and a half of running great yesterday (with several starts and stops) it went into some kind of limp mode last night right after I started it from sitting for a couple hours.  Throwing one code - P0216. I inspected those timing solenoid wires and there was clear evidence they had gotten very hot, whether it was from shorting or the pump heating up I am not sure due to another issue I found outlined below. I took the electrical tape off and the wires to the timing solenoid are frayed much more than they were from getting hot I assume. 

 

In some initial trouble shooting for P0216 I swapped the fuel filters on my fass and noticed the pump was surging bad at idle (post bleeding everything of course). I can open the fuel cap and here the fuel splash into tank in sequence with the pump surge (every second or so). Fuel pressure on my edge shows a bounce of a couple psi but always above 12. I'm assuming there's an air leak in the intake for that FASS somewhere causing some issues. 

 

This is all adding up to it looking like I just bought myself a vp pump, and I need to redo the FASS pickup line. I plan to try and redo the timing solenoid wires in a better way tomorrow and see what the deal is with the pump surge. I figure that regardless of getting it to run right now, that the VP is damaged from air in the lines. 

 

This is my first vp-44 truck and I've had it less than 2 months, already had to rebuild the nv5600 because I found metal chunks during a service. Coming from 3rd gens and still having a p-pump 12v, this truck is making me think anyone that keeps one of these vp trucks is crazy. I've spent more on this truck than the other 3 Cummins I've had combined and I've only put 500 miles on it. lol, thanks for all the replies and help though! Yal are great. 

[Great work!]

Metal Fuel line likes to crack or rot right at the top of tank.

[wil440]

4 hours ago, Great work! said:

Metal Fuel line likes to crack or rot right at the top of tank.

And I had one crack right under drivers floor inside a chassis clamp

[Mopar1973Man]

Hmmm... Maybe because the timing piston is seized up and the pump is constantly calling for advancement and the solenoid get hot from constant having voltage applied.

 

Quote

Fuel injection pump operation is monitored with ignition on. DTC will set when the engine speed is greater than 300 RPM, fuel command 5 mm3/str and timing command within a certain window.

 

 

Now like this pump I took apart the timing piston was so seized up I need a propane torch and heat the entire body around the timing piston to even pull it out. Back to the solenoid and it heat. So if the timing piston is stuck and ECM is calling for advancement 100% of the time but the timing piston isn't moving of course the solenoid would be hot and P0216 code present. Typically like we call it the death code because there is nothing left to do but replace the pump. Even if you had the tools to pull the piston out and replace the harden steel sleeve and the timing piston you still don't have the Bosch 815 test stand to recalibrate the PSG to the new timing piston then flash the new calibrate o the PSG.

 

Then most of the people here have been doing pumping and return fuel back to the fuel basket in the fuel tank. I'm not... I draw straw out of the tank directly. My fuel temp rarely are ever above 140*F but if you coming out of the sender basket in the tank you fuel temps can be as high as 160*F. Being I'm running the Quadzilla I can monitor the fuel temp. As for timing I can only see the "commanded timing" not the actual timing. Even when my last pump got stuck FULL advanced I could see the commanded timing that was normal but here is my truck barely doing 30 MPH and knocking hard from the advanced timing.

 

As you see my fuel temp and IAT run tag team.

 

 

Edited March 1, 2021 by Mopar1973Man

[Dieselfuture]

11 hours ago, David454 said:

 

In some initial trouble shooting for P0216 I swapped the fuel filters on my fass and noticed the pump was surging bad at idle (post bleeding everything of course). I can open the fuel cap and here the fuel splash into tank in sequence with the pump surge (every second or so). Fuel pressure on my edge shows a bounce of a couple psi but always above 12.

What kind of fass pump, if you have three lines which one of them returns back to the tank, then more likely problem is in the check ball and spring. After 5 years of having my fass my ball finally wore out, wouldn't build pressure above 14 put a new ball in, back to 19 psi. If your gauge is bouncing you need to put a snubber/needle valve so you don't destroy your gauge.

[Mopar1973Man]

11 hours ago, David454 said:

In some initial trouble shooting for P0216 I swapped the fuel filters on my fass and noticed the pump was surging bad at idle (post bleeding everything of course). I can open the fuel cap and here the fuel splash into tank in sequence with the pump surge (every second or so). Fuel pressure on my edge shows a bounce of a couple psi but always above 12. I'm assuming there's an air leak in the intake for that FASS somewhere causing some issues. 

 

Most likely the bounce is most people install the sensor right at the VP44 and the water hammer kills the sensor in a mere few months. NEVER hook a pressure sensor directly to the VP44 this is the source of the water hammer. Even my fuel pressure gauge is 5 feet from the VP44 on 1/8" brake line mounted to the fender. It's not the engine vibration like so many tout, actually its the water hammer and the distance allows the pulses to fade. I've got both a snubber at the tap point and a needle valve to shut down this leg of he plumbing if a failure would to happen.

 

Edited March 1, 2021 by Mopar1973Man

[David454]

10 hours ago, Mopar1973Man said:

Most likely the bounce is most people install the sensor right at the VP44 and the water hammer kills the sensor in a mere few months. NEVER hook a pressure sensor directly to the VP44 this is the source of the water hammer.

 

My sensor is basically on the pump from what I can tell, no sensor anywhere near the vp, and wiring to what looks like a sensor right on the pump. Is that the correct way to do it?  I have no idea how the rest of the suction side is set up but I will find out soon it looks like. Need to call the guy and see what all he did when putting in the FASS. I know he had the bed off at some point so hopefully the hard parts are there and it's just a loose clamp somewhere. 

10 hours ago, Dieselfuture said:

What kind of fass pump, if you have three lines which one of them returns back to the tank

The pump has a return line up to the filler neck, which is where I hear that splash of fuel every second or so with the coinciding pump noise surge. 

 

I am looking at vp44's from DAP. Looks like it's an extra $175 for the new computer. That's worth it I would assume? 

[Mopar1973Man]

Ok. You need a snubber installed before the pump and stack on the sensor. Similar to this...

[015point9]

Notice the end at the threads.   Looks sort of like an air stone for a fish tank.

 

"Sinistered" snubbers increase gauge readability by smoothing out pressure surges, pulsations and spikes, and eliminating instrument failure"

 

I got mine at the local hydraulic Fix-It shop

Edited March 2, 2021 by 015point9
Added info