Sorry...voltage on batteries. Even new ones, and especially if you've been cranking with a no start

But...what are your ICP and IPR% when cranking?

Also your RPMs while cranking.

RPMs, voltage, ICP, fuel pressure, signals to injectors, all have to be correct to fire up.

If it isn't starting, one or more of them are not correct. Once you find out which one(s), then we start breaking down WHY it is not correct

 

Batteries stay on tender. Don’t drive truck often. I’ll have to check voltage. How do I test percentages on ICP and IPR?

 

Battery tenders are notorious for keeping a top float charge but the batteries drop as soon as they get a load. It might take several DAYS to bring a battery back up to charge after a few mins of cranking (cumulative)

ICP PSI is what you want to check, as is IPR DC%, both in one of the OBD monitors like AutoEnginuity, Torque Pro, and now Forscan.

You can watch the Battery voltage on those, too

If you have a good battery charger, you can bring the batteries up to full charge. Likely if only using a tender, they won't be- keep in mind TWO batteries

 

uvch was partially unplugged, and clip was broke, replaced harness and gasket. put back together and tried to start. as long as i had foot on throttle pedal it would stay running, however it would lope real bad. plugged autoenginuity back in and got the following codes.
P1280 ICP sensor circuit low
P0472 exhaust pressure low
P0475 exhaust pressure control valve

 

Have you tried unplugging the ICP ? Checked the tinnerman nut on the IPR?

 

yes, checked both, went back out and plugged her back in and got the readings with KOEO
ICP duty cycle 14.84%
ICP volts .20
exhaust back pressure 12.51%
back pressure volts. .71

 

icp doesn't have a duty cycle. Ipr does

 

Okay, you want to get ICP in PSI, IPR DC%, RPM, Battery volts, all while cranking.

Can you log it?

IIRC, these values have to be met:

RPM > 200
ICP > 500
DC% (if it climbs with low ICP, trouble)
Volts > 10.5

If you're quick to watch it, you should be able to see these values and see why it is or is not starting without logging

 

I can’t keep truck running long enough to log it. I’ll try again tomorrow

 

You should be able to start recording before trying to start the truck, that way you can see what everything is doing even if it doesn't crank?

 

I’ll do that tomorrow when I get home from work

 

^^ This ^^

Please start recording and counting "one Mississippi, two Mississippi, etc" until it starts.

Seeing how long it takes to build the necessary values and what happens when it starts and/or stumbles.

Please be sure your batteries are both fully charged when doing the test. It can help to rule out voltage as the problem. If the voltage ends up being an issue, batteries and/or starter should resolve that

Looking forward to seeing the numbers you get, see if we can all figure out what's going on under that hood

 

KOEO
ICP 0
ICP volts .31
IPR duty cycle 14.84

While cranking engine
ICP 28-2900
ICP volts 3.8
IPR 55%

I shot a short video but don’t know how to post it.

 

Rpm and battery volts?

That is with icp disconnected?

 

ICP was connected. Batteries were good. Had them on charger all night and day.
When I disconnected ICP truck acted the same. Would start and immediately die.