Those are good numbers at idle (13.8-14.2); charging systems are all basically the same. As a rule charging voltage is about two volts above battery voltage. And then battery state of charge comes into play. And then temperature.

As the temperature goes down the proper charging voltage is higher. Turn all the lights and accessories on and run it up to a couple thousand RPM and see that it doesn't sag too much.

 

What about the 14.6v he is seeing? Especially right after a very high amp draw- enough to melt a screwdriver on that line?

 

The nominal numbers are important of course but it's just as important under what conditions, to make sense of them i.e. has engine just been started.. or consider temperatures are starting to get cooler lately, was it morning and 55° or something like that?

Using the alternator as a temporary arc welder would concern me though, yeah. But, the numbers don't seem too out of line necessarily.

 

I'm thinking the regulator is out?

Firefighter- what is the resting voltage of your batteries before you start your truck, and after it is running about 5-10 mins?

I suppose it is possible you have a bad cell or something in a battery, making it scream for "more voltage" until the alt is going flat out?

But it's equally possible the high amp incident shorted a wire and that's causing problems and the alternator is simply responding to the extra draw

This is where a guru with more experience can help narrow these options down

 

I have whats know as a rolling idle as well. It doesn't do it when cold, just after warm up, nor does it do it all the time. So, Anyhow I hope to learn something here that may help me find my problem as well.

 

No regulation would mean 16 or 17 volts easy? Consider in real cold temps it's normal to see 15 volts or so. Asian vehicles often run a higher set point, as an aside. I just don't see 14 to 15 volts as a cause for concern all things being equal, again it depends on the circumstances.

 

I have had an alternator lose a regulator before. Truck Guage was showing like 18 Volts. Right now the dummy Guage looks to be in the normal spot. Nominal voltage on the batteries is 12.62V and 12.59V. That was taken after I drove the truck to my Sidejob and back. So the truck is warm. Weather channel says its 69* out.

Alright after 10 min of running and shut off. Battery that was 12.62V was at 12.83V. And the one that was at 12.59V was at 12.61V. Batteries are going on 2 or 3 years old. I can't remember. Also checked the battery water. One was just a touch low but nothing major, I topped it off.

I am sorry for the question. But don't understand. Let say the alternator was bad. Why would it be causing the idle to fluctuate?

 

It may be the alternator/regulator is OK, but something else is lunched.

 

Those numbers sound okay.

If the alternator was surging, or kicking up and down, it could be changing the load on the engine quickly, which could show up as a stumble.

Of course, these are pretty big engines, so maybe wouldn't show up here? I know they will on bikes

If you hadn't surged it, likely wouldn't be looking so carefully at the alternator. But it's looking okay?

 

Okay. That makes sense.

For the record, batteries were at 12.33V on a 59*, plugged in start up this morning.

 

Okay, moving on....

Can you get us a short vid of the idle variation? Let us see the RPMs, hear the motor?

Can you log with AE, TorquePro, or ForScan?

1. What brand and weight of oil? Last oil change?

2. Last time you changed CPS, ICP, IPR, or TPS?

3. Any oil or turbo leaks? Using any fluids? Anything unusual- smoke (color), knocking, vibrations?

4. Any similar variations while running, maybe while holding pedal steady and cruising?

5. Have you done a Hutch mod? Tell us what you did. Replace all the rubber lines between tank and pump?

6. Fuel filter. When did you change it last, what brand, what does it look like?

7. Fuel bowl. When did you rebuild it, what parts did you use, did you replace the Parker sleeves in each of the fuel lines?

8. Tuner? What tune? Have you tried it in stock mode?

9. FRx or regulated return?

10. UVCH- when did you replaced them last?

11. Air. What filter and media? When did you change it last?

12. Turbo wheel?

13. Wastegate? Disconnect and plug the Redline, see if it makes any difference.

14. EBP. Is it deleted? Pull the solenoid, replace the orings, inspect for damage or unusual things?

15. Injectors. Stock? How many miles? When did you do the orings last?

16. Fuel additive? What brand, how much, how often?

17. Auto or standard trans? Does it do the same thing when in Drive with foot on the brake?

18. Unplug the ICP and see if it makes a difference?

Look at each of the items above and make sure you understand what we're looking for and how it could affect your idle. YOU are the one closest to your truck and will have the best "feel" for what is going on.

You've checked the ICP and IPR wiring, due to the direct short? Make sure they didn't get nicked or damaged/melted insulation.

Then maybe we can start ruling things out. If there is something we can take off the list now, tell us why (maybe you already checked it?)

Lots of stuff, but as you said, you just want to get the problem fixed. I'm with you on that one

 

Edited your questions. Hope that works.

 

Great responses!

Others will have some ideas, I'm sure. Here are the ones that jump out at me.

1. 283k on injectors is getting worn. You are using T6, which "helps"

2. Air in fuel is hard on injectors. Without FRx or similar, air MUST go through injectors to get out of fuel rail once it makes it out of the bowl. FRx doesn't solve ALL of that, but helps.

3. Running out of fuel at 1/4 tank? Yep, broken foot, clogged filters, stiff duckbill/bypass, sucking air in the quick disconnect fitting in the line, etc. I'd fix THIS first. No sense replacing anything else if you are very likely getting air

4. Lack of Fuel additive. Our trucks were before ULSD was mandated. ULSD doesn't have the lubricants and such our trucks need. You should probably consider something like Power Service added to every tank. Grey bottle in summer, white in cold weather, if you get it.

5. UVCH. Keep an eye on them at 8yrs old. Does the idle change sound like it could be a MISS? Keep in mind at 7.3L and V8, it won't miss the power at idle, but could be affected. Watch for this kind of problem with UVCH or injector.

What problem are you having with AE? I have it here, maybe we can help you figure it out?

 

1. I know I need injectors. Believe me Tugly has been telling me that for a while now I just don't have the funds at the moment. They seem to be going quicker and quicker though. It does make me worried though going into winter. I rely on this truck a lot in the winter for my snowplow accounts. Can't have a truck that doesn't start or runs like crap. And the white stuff is coming quick. Currently it has been getting down to mid 50's at night, and it is taking longer and longer to start even with cycling the glow plugs. I installed a remote start a couple years back, and it takes long enough to turn over now that I can't even use the remote start.

2. I have looked at this mod many times. It is something I could probably spring for. I need to get a list together and do it all at the same time. Have to get the fuel tank crap fixed too.

3. This is on the list. Have to order the new filter, was thinking of going with the Racor PS120-02, and get the other supplies around. Just plan on taking a weekend and getting it done.

4. The more I think about it I have probably helped the injectors to their demise with not regularly running fuel additive, which doesn't make me happy at my self at all. I have periodically ran the Power Service stuff but not religiously as I should have been.

5. I could replace the UVCH harnesses to rule that out. I have a new one in the garage, would just have to order another one. I was planning on doing that when I did the injectors. I wouldn't call it a miss. It's weird. When it does its thing when the rpm's are the lowest it runs smooth, when the rpm's increase it runs rough, yesterday according to my AIC unit it was as little as 7 rpm's that were causing it to run rough. When it is in gear a couple times sitting at a light I thought it was gonna die and the rpm's were up. But it didn't. I will try to get a video tomorrow that shows inside and out what she sounds like.

6. The A/E Gilleto or whatever it's called update is kicking my but. When I had the pervious version Tugly had helped me out and got me to be able to do at least the basics and I felt pretty well about it. The email about the update came out and I said to myself it's free so why not do it. Well then after I hear everybody saying don't do it and I am stuck. I am not a very computer savvy person. If it worked on a iPad I would be a lot better off. I struggle with the interface getting everything up and running. And to top all that off my 4 year old Toshiba laptop has decided that it no longer wants to work very well. I am just a mess I tell ya.

So am I feeling you out right and you are thinking that it could be just some other random thing/s that has started happening the same time as my little fireworks display that is causing my issues? So we are having to start from scratch?

 

Lol. Sounds like you need to pull up a seat next to me...in my corner

If were me, limited funds and must-do things, I'd start with the Hutch mod, first and foremost, including a couple short pieces of line. Air messes up everything and you are almost definitely sucking it in.

The FRx is helpful, but once the air is gone, how much? It can help performance, maybe due to flow I noticed the most help and lessening of cackle, but it would have been reduce (how much?) when I later did the Hutch anyways. I feel better about it, especially when changing fuel filters, I cycle the key a few times to circulate the fuel and know the FRx will help with anything that made it to the fuel line.

Fuel injectors NEED fuel and oil pressure. Then a little spark to fire. That's it. Clean up the fuel as we've mentioned, keep the oil clean and keep an eye on things.

Do you have anything Android with bluetooth laying around? If not, they're like $50 or less. Another $20 gets you Torque Pro and a bluetooth adapter. Then you can watch and keep an eye on things.

True be told, AE is great for troubleshooting and pulling sensor data and running inbuilt tests. For logging I prefer Torque Pro anyways. Attractive and fairly stable monitoring "dashboard" and can log and email quite easily.

If you're starting now, even slowly, the fuel hutch mod can only help.

Start using the full additive amount, to help keep what injectors you have happy, well, happy

There are some super duper lubes and stiction stuff that some have had luck with. I don't really know anything about it. Maybe you can tap Tugly or some others to see if you think it might help a bit