Strange Starting Problem??

[Justin@DP-Tuner]

So, volts are at 12.45 first, they drop to 11.7 when the key is turned on to warm up the glowplugs. It then drops to 10.54 when cranking.......?

That all sounds normal.

Couldn't see any white smoke at all while cranking......?

No white smoke means no fuel. When this occurs, it usually means you have not hit enough ICP for the injectors to start firing. They need to see 500psi of ICP before they will begin to fire. It could also be countless other things that would disable them from firing (wiring, sensors, etc), but that is common. Have you checked oil level in the HPOP reservoir before you attempt to crank it over in the morning? Should be about 3/4" below the top of the reservoir.

If it's going to 10.5 or below the injectors won't fire. What CCA are the batteries you have? 850cca is the absolute minimum in cold states.

Not 100% true here. I know that is the general consensus, but the truck will start with less than 10.5v. Mine did many times when my batteries were weak a while back. I always monitor voltage when cranking. It would start when voltage dipped all the way down to about 9.6v. Always thought it was 10.5v myself too, until I started watching it start below that on my truck.

 

[stillbuildin]

Thanks all for this info, really appreciate all the input!

Justin, yes the hpop level is good before starting. Although I've just noticed the icp plug is full of oil! But if I unplug it, it makes no difference to the truck starting.....

 

[Justin@DP-Tuner]

Thanks all for this info, really appreciate all the input!

Justin, yes the hpop level is good before starting. Although I've just noticed the icp plug is full of oil! But if I unplug it, it makes no difference to the truck starting.....

Okay. Do you have a scan tool you can connect to watch ICP while cranking? Should be able to do that with an app on your phone and the bluetooth dongle. If you are getting at least 500psi of ICP while cranking, you can pretty much rule out ICP being the problem. At that point, you can move on to other possibilities.

Also, any codes present?

 

[stillbuildin]

I tried a buddy's Innovo scanner, showed nothing. I've ordered the Bluetooth dongle to use with my android - should be here in the next week or so I didn't know I could monitor icp on it, that'll be great!

I'll learn the device and report back. Thanks again for all your input!

 

[m j]

how do you know when the GP cycle off? on my 97 I look at the Volt gauge, the 01 doesnt have a Volt gauge so for that one I know there is a GP issue when it doesnt start, usually means the relay is burnt