1999 F-350 with the IH 7.3 Diesel, 6 speed.

I have confirmed the wiring harness continuity and appropriate voltages are correct for the exhaust back pressure system. No shorts to ground and the right VDC on the correct wire.

The Exhaust manifold BP pipe and sensor have been changed.
When I unplugged the engine oil temp sensor the EBP Regulator properly went off line.
The EOT sensor was then plugged back in to the harness.

This AM it was about 32F and it seems the air temperature sensor is working as the surging has begun again and lasts until the engine gets up to operating temperature.

I am considering that the EBP Regulator is not working right as the engine continues to surge between 1200 and 1800 RPM.

I would like to know how to test the EBP Regulator before spending a lot of bucks.

Anyone have an idea on this?
Thank you!
Eric

 

Have you thoroughly checked out the glow plug system ? If so, how did you do that?

 

Using the correct oil? If not, incorrect oil, wrong viscosity or oil that can potentially foam will cause 'romping'.. Just something to be sure on for a cold surge issue...

 

Hanky,
Oil is per operator's manual and no foaming or other oddness. It gets changes on schedule. Using Rotella 15-40 IIRC.

I can hear the intake (I think) wheezing until the engine gets up to operating temp.

How do I verify that the EBP Regulator is not cycling on its own or leaking?

For the GPs. I checked the resistance at each connector outside the valve cover. Driver side was 1.0 ohms per plug. Passenger side was 6.0 ohms per plug. Going to change them out.
I also determined the GP relay was shot and have installed a new one.
Thanks!
Eric

 

15-40 oil is OK where the temp stays up pretty warm, but I'm pretty sure your owner's manual recommends a thinner oil for operation where the temp goes down to below freezing. Have you had a chance to check that out? (10W30)The glow plugs heat the intake air to help ignite the injected fuel, but the engine has to spin over a certain RPM for the injectors to fire.

Sometimes a loose intake hose clamp will allow air to escape instead of going into the engine and it can produce that wheezing sound.
Also the ohm rdg should be the same for each glow plug.

 

Hanky,
Temps now are above freezing but I will be sure to verify the oil.
Had not thought of the air intake hose/clamps. I'll check those tonight. It would be great if it is something simple like that!
Thanks for the reply.
Regards,
Eric

 

All air intake hoses are good, connections tight no tears at the joints.
Still surging below about 40F.

I am guessing it is the EBP Solenoid "cycling". But need to verify that as a new one is $400.