Cold dragging of motor.
 

I have a 1997 f350 4wd PSD. On the cold mornings, even after 10-15 minutes warm up. The motor starts moaning( while driving) and loses power, then will go normal, then repeat the bogging down. I can hear the heater fan slow down with this. Maybe vacum? Just does this when cold, or I don`t notice when warm.
Thanks in advance.https://www.dieselbombers.com/images...C_thinking.gif

I have no idea what your talking about

Check the alternator and batteries. Batteries may be getting too low before alternator starts the charge cycle

Sent from my SCH-R970 using Tapatalk

it is like 1 0r 2 of your cylinders are not firing. And then it will run fine. and then it will pull hard again.

Could it be the ebp closing when it's not warmed up. Maybe the oil temp sensor is only working intermittently

Thank you folks, will check those things out.

This is what I would check. When t does it, pull over, open the hood and look at the EBP Valve on the exhaust outlet side of the turbo. There is a rod from the EBP regulator in the turbo pedestal, that goes under the turbine housing, to a lever under the EBP valve. If the rod is extended, the lever will be turned to the exhaust. If the truck is off, the lever should be pulled back towards the pedestal.

That system should come on if it is under 40F (measured at the IAT sensor. It stays on until the EOT (Engine Oil Temp) gets to 170 degrees... but there is supposed to be a cutout whne high RPM or high load.

How do I know that? Mine had problems. If you find that is the problem, disconnect the connector to the EBPR (connector bolted to the compressor housing on the driver's side. The EBPV should then stay open. No harm in that, but sometimes that will throw a code saying its not working.

Mine was driving worse than that. It was sticking and not releasing when it should have. When I did a pedestal EBPR and outlet EBP delete, (Also did a EBPR electrical hack) I could see where it was sticking when closed. I don't miss it at all. In fact it runs much better without it. More flow with the high-flow housing (without the EBPV). The delte pedestal has more airflow, so lower EGT's I have a tune with a high-idle to help it warm up... which is the only reason that valve is supposedly there. (to help it warm up.) I think plugging the exhaust was a bad idea (theory) on how to warm up a motor.

Thanks to All.
 

Thanks to all. It was the EBP valve. You folks on this site are the best.