Well I'm going to jump on the cold start band wagon here. I've determined from other threads and replies to my own posts in other threads that my 7.3 is in overall good health. Great to hear that I don't have much to worry about, but I do have a cold start annoyance I'd like to figure out.

Let me start out by saying that I don't know what is normal for these trucks. So if I drive the truck today and go out to start it tomorrow or the next day, I won't have a problem. If it let it sit for 4 days or more it takes a bit more effort to get going, I've let it sit for 2 weeks and it was about the same as the 4+ day starting.

Rather than trying to describe what is happening I'll link to a video I took last time. In this video it sat for about 7 days since last started. I was moving a little slow cranking because I was attempting to data log the start on my laptop. I forgot to save the first crank and start, but a log of the second crank and start are attached.

I apologize for the radio, it didn't dawn on me to turn it off until after I got the log set-up.

The gauges and data log are all the gauges I have at the moment. I haven't gotten a fuel pressure gauge hooked up yet.

 

Was the first crank spinning significantly faster?
That cranking speed is way too slow.

Dying after starting like that ain't normal,indicating that you may have more than just cranking power issues..

It purs like a kitten when finally fires up!

 

Same thing my OBS did when my LPOP took a dump. Your oil pressure gauge never registered oil pressure on the first start.
and your crank speed is way too slow you need juice to spin this engines, could be battery's, cables or the starter itself. Test/fix those first and go from there.

 

Here is a graph of your relevant data...my first take is weak batteries or a weak starter...would appear to me that after the 15.4 s mark your glow plugs cycled off and your batteries had enough juice to spin the starter fast enough to finally build the required ICP to start...

 

Well, it is that time of year. I have to be honest here sir, I did not expect to see this thread from you. At least not this time of year as the weather is still quite warm in GA and down near Macon where you are.

It was 4 years ago this month that I installed a Denso starter and NorthStar AGM batteries, this was the result.


Adam brings up the LPOP and oil pressure gauge. I clued into that as well during the first start attempt, but wrote it off after the second start when the gauge registered pressure. He knows a lot more about these trucks than I do though, so there is that.

Josh was nice enough to chart the data for us and I thank him for that. He also gave his opinion on what he saw or didn't see in the chart. Thank you again sir!

During your first start attempt, as the RPM starts to ramp up your DC voltage (VPWR) dips down to 10v. This is below the minimum voltage required and stated by Ford in the service manual.



This is the highest RPM point during the first start attempt at 182 RPM. As you can see, the VPWR is still quite low.



After the first stall event and you sat for a moment, the VPWR reaches 11.44v at the peak. Immediately following that peak measurement, you started cranking the engine over again and this is what happened.

The VPWR dips back down to nearly 10v like it was before.



Even after the truck starts and is running smooth, your VPWR is still quite low as seen below. This is the very end of your data log.




I believe Ford states 10.2v is the minimum starting voltage, but we always go by 10.5v just to give a bit of a cushion and no two trucks are the same after all of these years. So, it appears your GPR and GP's are working properly, but you may want to test them if some of the other courses of action do not resolve the issue. The LPOP would be my last suggestion, but battery terminals, main ground points, cable ohm/resistance testing, load testing, starter connections, etc would be first on my list. A new high torque gear reduction starter may be needed, I don't know at this point.

 

You can see both cranking attempts in the video. well I guess three cranking attempts since it didn't fire off on the second. The first one where it starts and dies was the first attempt of the day, I just didn't manage to get the Forscan log saved.

That's the kind of stuff I need help with. I wouldn't have known that was too slow on cranking speed since it does start.

Thank you. Didn't know if it should register OP while cranking or not. Wasn't something I knew to watch for since it appears good while running.

Thanks for posting for people to see. I got the PID charting tool saved to my computer, but felt it was better to post the CSV for people to get the real info. I can't confirm or deny if the GPs cycled off then, but I would point out that when it started and died was before this chart even starts. Don't know if that means anything though.

Yeah, it isn't weather related. It happens any time of year regardless of temps, and it sounds like it has been this way for years. I'm not positive, but I think this is the root of the issue that dad was trying to fix with stiction eliminator. He claimed that additive helped, so I've been looking at it as an oil/fuel issue. I'm starting to think the additive may have helped, but not in the way he thought, or that he saw the results he wanted to see. You know like when an items claims to add X HP, so you feel like it added HP even if it did nothing. Know that has a proper name but I can't remember it.

Sous, I think you might be onto something. I hadn't even considered battery voltage until I was looking at it again to post yesterday. Even then I saw the low voltage at the beginning of this log and chocked it up to being drained from the first start attempt where it died before this log started.

I notice that in the video your OPG doesn't register until the truck is running either, and as soon as it is it snaps to good oil pressure like mine does. I've read about simple checks for it, but they would be a little difficult to perform solo. I'll keep LPOP in mind, but I don't think that's going to be the issue.

I hadn't considered batteries because I didn't have anything to compare to for cranking speed and the gauges shows to be charging when the truck is running. Previous data logs I did with the truck running all show better than 13.5 volts. Went back and checked an older starting log, one where it had just sat over night, and it too shows low voltage. Not 10 volts low, but less than 12.

Also went out and put eyes on the terminals, they are nice and clean.

These batteries are AutoCraft gold from 11/18. I don't know if I can swallow $400 a battery for AGMs, but I seem to recall people complaining about the AutoCrafts over the last few years. Might be time to replace them again. Next time I crank it after sitting like this I'll put the battery charger on it first and see what happens, if it starts right up then I've probably got a battery problem. That should be in the next few days. I'd do it now, but its been raining all week and I need to head for work.

On that note how would one connect a battery charger on a dual battery setup like this? Connect to one battery and it'll charge both?

 

With the truck running, the 13.5v is coming from the alternator. Obviously when the the GPR is on and the truck has not started, there is a large draw on the batteries where the alternator is not producing power.

Just for comparison sake, below is a recent "log" of my observed voltages during a similar situation as you were describing.

Ambient temperature - 48*
Resting voltage - 12.8

• Ignition on/GP's on voltage - 11.6
• Ignition to start voltage - 10.9
• Truck started in ~1 second of cranking
• GP's on/engine on voltage - 11.8
• GP's off/engine on voltage 14.2

Data source: https://www.ford-trucks.com/forums/1...l#post19714947

Ambient temperature - 25*
Resting voltage - 12.7

• Ignition on/GP's on voltage - 11.3
• Ignition to start voltage - 10.8
• Truck started in ~1 second of cranking after 54 (stopwatch) seconds of GP's on
• GP's on/engine on voltage - N/A GP's went off immediately after engine started
• GP's off/engine on voltage 14.2

.
Ambient temperature - 25*
Resting voltage - 12.8

• Ignition on/GP's on voltage - 11.4
• Ignition to start voltage - Forgot to look
• Truck started in ~1 second of cranking after waiting 1 second or less of GP's on
• GP's on/engine on voltage - fluctuating with blinking GPR LED 12.9 - 15.0 with inconsistent readings on the low and high end. For example, it may read 12.3 one time on the low end and 15.5 one time on the high end.
• GP's off/engine on voltage 14.2

Data source: https://www.ford-trucks.com/forums/1...l#post19715989

The terminals may be clean, but the water may be low or the wires may be corroding from the inside out. An ohm/resistance check is in order. Also, check the engine block grounds and the starter positive connections.

One of the biggest reasons why I went with a reputable AGM battery is because I was so tired of replacing LA batteries under warranty or with a prorate charge. I need something that is reliable, strong and will be there when I need it. We take the truck to some very, very remote places to camp and I don't need a LA battery letting me down. As my other vehicles batteries die, I have been replacing them with AGM as well. No regrets...

But, I also know that the main wires are good to go as I tested the OEM ones and then installed more just to make the system as efficient as possible. There are some decent LA batteries out there, like the CAT ones that a friend of mine installed recently. I was simply exhausted with them and said screw it. If they last 6 years I am even money. If they last 10 years I am well above even money and saved time and frustration. So, for me and my application it was a hard pill to swallow, but it is a once a decade pill, at least I am hoping so.

Yes, the battery charger should charge both batteries if connected to one set of terminals. Again, the OEM wiring is critical here. Some people feel that a dual port or charge battery charger is required on a dual battery truck. That is not the case at all. The batteries are hooked up in parallel so the amperage increases, not the voltage. If all the wires are in good shape, the batteries should read EXACTLY the same voltage when a multimeter is put across the posts of an individual battery. The batteries work as a "single battery" in a parallel configuration as in our truck. There is no need for a dual port charger if the system is as efficient as it should be.

If the truck starts right up after being on the charger, you may in fact have a battery problem. But, you may also have a connection problem at the starter or engine grounds too. Or, an internal wiring issue... It happens... One step at a time here though and we as a community can recommend your next course of action based on your observations.

 

With good batteries, good terminal connections/wires, and a good alternator you should be seeing north of 14v while running, and north of 12.5v at rest...these trucks all do have at least a slight parasitic draw, so if its sitting for a couple weeks at a time between starts a trickle charger is helpful at keeping batteries topped up...but even mine which sits usually 5-10 days between starts without a trickle charger doesn't drop below 12.4v at rest....however I just replaced my JUST over 3 year old interstate batteries last winter....and unlike Sous I decided to go with just the cheap Walmart Everstart MAXX batteries...under $110/ea with 3 year free replacement...I figure if I'm hard on them and they fail early I get free replacements and there are walmarts EVERYWHERE and if they make it more than 3 years I got my monies worth out of them.

11/18 means you're coming up on 3 years for the batteries, not out of the norm/question for them to have gone down hill by then especially if its been 3 years of frequent sitting between charges with no battery maintainer on them....

 

I too agree this is very slow cranking, especially for “warm” weather. The guys already have you headed in the right direction.

You may want to check the batteries individually as well. They can reluctantly start on one good battery when the weather isn’t too cold. Might just have connection issues to one of them (been there, done that).

Something I wanted to throw out to the group…
The fuel pump kicks off after about 20 seconds. During the first start attempt the FP may have already stopped before cranking. Not sure when it decides to turn back on without a key cycle.
Anyhow, one time I cycled the glow plugs while doing something outside the truck so it was probably a full minute before getting to start it (just turned to start, no key cycle). The truck did not like that at all. I always assumed it was from the FP kicking off.

 

Understood, but charger is something I can quickly and easily do before next time I take it for a drive. Pulling out the multimeter and chasing cables, not so much.

Cleaning grounds and new cable may be in order, if that's the case a lot of cable upgrading may be coming. I want to put those heavy duty cable quick disconnects at front and rear bumper of both my trucks for jumper cables, winch, etc.. I can't recall the proper name, but the type you'd find on the battery of an electric forklift. If I'm playing with battery cables it might be a good time to upgrade power and ground wires and run those quick disconnect wires.

Sous, if I used my truck like you do, AGM would probably be worth it. Way things are for me right now, MD_7.three's way is the better fit. That's not saying that my situation won't change down the road.

An onboard battery maintainer is on the list for future additions, but I'm pretty certain it was never a thing in the trucks past. From the way he talked, dad would run the truck every few days to avoid this issue. That said I don't know if "running it" was starting and letting it idle for 30 minutes, driving to the corner store, or making the 40-50 mile trip to the hunting club. Could have been any of those or anything in between He did get into the habit of plugging in the block heater during the few cold weeks we have down here, but. I'm pretty sure the only time it ever saw a charger was if the batteries needed to be charged.
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I would like to get where I can let it sit for a couple of weeks without having trouble staring. I would be ok with using a battery maintainer as part of reaching that goal.

 

@Sous just picked up a new multimeter this afternoon since my old harbor freight freebie (that was given to me by someone that had a few) decided to pull a disappearing act. I've had a $100 dollar gift card riding in my pocket for 2 years. Decided it was time to get a decent one since I'm into electronics and going to have plenty of rewiring projects in my future between the F100 and hopefully getting back on the V8 Ranger in the future. Didn't go Fluke nice, but did get the beat Klein that Home Depot has, MM700 I think. Time toearn how to use one of these again, ain't really used one since tech school over 15 years ago.

So what am I wanting to check with it on the cables, batteries, and charging system? Any good guides you can recommend?

Still going to throw the charger on it then I get home in a bit and see how it starts tomorrow. It's been 8 days since last start. Might be a bit before I can actually start shooting wires.

EDIT: I didn't check them individually, but prior to connecting the charger I did check battery voltage with the new MM. They showed 12.58 volts. I've got one of those "smart" chargers, Schumacher SC1281, that tests battery and attempts to desulfate if needed before doing the automatic charge/maintain thing. When I hooked it up is was showing 12.4 volts and it started charging. I know it isn't proof of a good battery, but it didn't show bad battery which I have had happen before on other batteries.

 

You can get a fairly decent load tester at HF and check them individually. Parts stores will load test them for free as well.

 

Fluke is very nice stuff, but Klein is nice stuff too. We had an entire assortment of Klein tools when I worked telecom outside plant. I still have some of those tools 25 years later and they still work great.

As for using the multimeter (MM) to check the integrity of the cables, that is really quite simple. Not as simple as checking the voltage, but that should be the first step, checking the voltage. It looks like your voltage setting is autodetect between AC and DC based on the image below.



With the batteries connected and in a resting state with or without the charger, you should see the same voltage reading from each battery down to the hundredths if possible. At least to the tenths position though. Once the truck is running in a cold and hot condition, you should see the same voltage reading down to the hundredths again. If so, this means that the two batteries truly are working as one battery as designed and intended.

If you want to go further and check for resistance in the wiring, you use the "ohms" setting which is the one just to the right of the voltage (V) setting. You should not have to swap the positive lead port as ohm and V utilize the same port which is the one to the top right of the common (black) port.

There are many videos out there on how to use the Klein MM700 if you feel like you want to watch them.

Going forward with an resistance test of the wiring, you want to establish a baseline and short the leads together which should result in a 0.1 result. If it says OL or something else, check your leads for connectivity.

As you go to testing the cables, you really want to have the battery side off the ground and test through the ground point like on the engine block, then again through the cable lugs only. Be sure to take notes along the way if you are anything like me as I get the numbers and results all screwed up. There are standards or guidelines of what a cable should read during a resistance test based on length and gauge (diameter).

There are "wire resistance calculators" and "ohm test charts" out there for you to use as a reference. The length of the cable does not need to be exact, just close. Frankly, if you are seeing very low resistance in the display from a cable, it is safe to assume that cable is good. The cables are not very long and are quite large gauge wire. You may want to test all of the positive and negative cables from and to the batteries, then the positive cable to the starter. It would be best to isolate the batteries from the circuits so that you don't cause a short to power and blow a fuse or fuseable link.

When I upgraded to AGM 930 CCA batteries, high output alternator and high torque Denso starter, I also upgraded the main wiring under the hood. Below is a link to my thread on how I accomplished that.

My truck needed to be more POSITIVE and ENERGIZED!

You can see how I went about that following the guidance of some FTE'rs before me. This may not be necessary for you and you may only need a small upgrade like a better starter, new batteries, batteries serviced or a wire swapped out. What I do to my truck is not a good solution for everyone else. But, taking the proper diagnostic steps to identify what is ailing your truck is the right way to go about it. Either that or start throwing parts and money at it like a "buckzooka" round and you might get lucky.

Keep us updated!

 

Yeah, doesn't seem as simple as batteries here. Probably need to get a load test to fully rule them out, but with them fresh off the charger, how the truck started didn't change.

I'll say this now so that I can look back and see how close I was later. I predict that the end result will be better batteries, upgraded cables, and one of those fancy starters. Then find out that none of that was the problem and it's something to do with the oil or fuel system as @z31freakify and @RacinJasonWV suggested.

Can you ohm check a battery cable like this with a multimeter? I think these multimeters only use a very small current to test. Cable might be able to handle that small current no problem, but starting current might be a whole different story. I think I've got some reading and studying ahead of me.

Sometimes the "buckzooka" is ok, but not always. Cheaper stuff like battery cables, fire away. More expensive stuff like starter, batteries, and injectors, better to keep the safety on (or booger hook off the bang switch if you prefer Glock) until you've verified the target.
Sometimes firing that "buckzooka" at the more expensive stuff is ok too if you can justify an upgrade in the process. IE: Better starting with the gear reduction starter, better reliability with the AGM batteries, or more juice with a bigger alternator.

After watching several Matt's Off-Road Recovery videos on Youtube, I think I've talked myself out of running battery cables to the front and rear bumper. I've been watching them for a while, but just started paying attention to the winching he does with his trailer for recoveries, That's the kind of winching I'm most likely to be doing, dead ATVs and the occasional car/truck. Noticed that for most of it he uses a portable jump pack for his winch power, and I think that would be a more practical solution for me than running power to a quick disconnect. I wouldn't be limited to using the trailer and winch with the F-250, I could grab the jump pack and hit the road in another vehicle if that's all I needed. Plus it would get me a portable jump pack which is something I probably should have had years ago.

I'm still good with getting new battery cables if necessary. I've already got cable cutters, crimpers, heat shrink, and wire loom. Just need to get terminals, lugs, and cable in the appropriate size.

 

Yes, you can use your home use MM to test the cable for resistance or lack there of. That is why I eluded to if you see anything other than the very lowest of readings, you may have an internal cable problem. May be the key word.

I believe your quick connect idea was talking about something like an Andersen quick connect. I have some for the front of our 5th wheel in order to quickly deploy a mobile 100w solar panel and PMW charge controller. No alligator clips or messing around with wires, literally plug and play. They have their use that is for sure, but not all uses are good for them.

Check the cable integrity and clean ALL of the major connection points for the main cables before buying anything. The back of the alternator, the engine grounds on both sides of the engine, the starter connections, etc... Go from there... That is free to do except for the time, then start spending some money if you don't see the results you like to see.

I agree that your batteries are probably due for replacement, but put some elbow grease in first. Either way, the refreshing of the connections will help you in the future if/when you need new batteries or starter.

Speaking of starter... Have you seen the 6.7L starter mod?

Starter

• 6.7 Starter Modification
• 6.7 Starter Installation in 7.3