I put new batteries in (Exide 27) a few months ago. The truck has started fine.We've recently been in a cold snap (highs in the upper teens) and the truck often will not start. It is very slow cranking. Very slow, to almost dead. If I put the charger on and set it to 10A, I can wait about 15min and can get it to start. However, it will NOT start and run unless I hold the accelerator pedal down. Once it fires, I have to continue to hold the idle high for about 30-45 seconds before it'll keep itself running.This is more so an issue if I don't plug it in during the night.I have to go out (at work) and start it every couple of hours, otherwise it will not start when I leave work in the evening..

Load test the batteries?Starter brushes and contact in good condition?Voltage drop test your main starter leads?As for the idle issue that normal for the VE and P7100 because the pump has a static set idle. The problem was over come in the VP44 pumps using coolant temp to set idle speed.

Yeah mine started fine at 30F and 20* timing (cranked and cranked) after sitting for months with a corroded to hell battery and dry cell all in toolbox far from the starter. It cranked over slowish but still started after 5 seconds or so. Being your batteries are new, you can load test them again but I would definitely be checking out the starter or bad connections. And yes the idle thing is from the load of a cold engine. When the engine is warm it idles at X rpm and takes X amount of fuel. When it is cold, it takes a lot more fuel to do X idle RPM and since the pump has no way to account for this, it injects the same amount of fuel which isn't sufficient. I have to do the same thing... Tap the pedal to start and hold it at 800 for 30 seconds ish though I have a choke cable thing I just pull out and it holds it for me. They do make an aftermarket high idle kit now that uses a vacuum solenoid thing.

I'll have them load-test the batteries this afternoon. Starter contacts are good.I did see some corrosion on the cross-over cable from the passenger side to the drivers side battery. Corrosion was on the pass. side positive cable, right where it enters the lead terminal.Once started, it charges 13.8-14.3V so that part is fine. It's been out in the parking lot for a couple hours now, and I went out, turned the key on, waited on the WTS light to go out, and it fired right up. it's 21*F out right now, and the coolant temp gauge is buried on cold side.

Eh I'm betting mine would start just the same with just the 1 battery. I'm pretty sure the other battery is toast. I wonder if this slow cranking has anything to do with your crappy mileage. As in some sort of mystery load that is dragging the engine down. I mean, it will crank slower in the winter...but what you describe seems to be on the extreme side of "slower" as in something is wrong. Does it bar over just as easily as your other engines did?

I'll have to see, ISX. I haven't barred this one over yet. I know the first 12V and the 24V turned quite easily with the alternator nut.It's always started really easy, per se, until this cold snap we're in, came through.