1999 f250 standard 266k miles
Has a SES light throwing p0603 and p0470
When the light is on the truck has a slight miss feeling to it and it seems low on power when the light goes off it will buck and sputter the lever off and it seems to have loads of power then the light comes on it will buck and sputter then go back to having low power. I have also checked the valve cover harnesses and they are good not sure where to go from here

 

Also it has a slightly longer than normal crank time but it's spinning fast

 

Sounds like a burnt pin or loose connection to the UVCH.
Common issue. New harness about $70 each side. I would start with the passenger side first.

 

Trouble Codes P0603 and/or P0605: Some Powerstroke trucks may exhibit codes related to keep alive memory--KAM (P0603); or read only memory--ROM (P0605). P0603 may be set if the batteries or computer are disconnected. On the 7.3 P0603 can be cleared by running the engine for at least 30 seconds, then clearing all codes. For the P0605 the computer should be reprogrammed with the latest available calibration. Broadcast Message 1076.


LACK OF ACCELERATIONERATION WHEN COLD; LIMITED RPM; HISSING NOISEUNDER HOOD; POSSIBLE DTC'S P0470-P0478:7.3 NAVISTAR ® FORD® DIT DIESEL QUICK REFERENCE INFORMATION LACK OF ACCELERATIONERATION WHEN COLD; LIMITED RPM; HISSING NOISE UNDER HOOD; POSSIBLE DTC'S P0470-P0478:

Exhaust (Back) Pressure Regulator valve/servo. When the engine is cold--EOT less than 140 degrees--and the ambient temperature is less than 37 degrees, the PCM activates the EPR solenoid to divert oil pressure to the EPR servo which closes the EPR valve at the turbo outlet. This causes exhaust backpressure to help the engine warm up more quickly.


The PCM monitors the amount of backpressure through the Exhaust Backpressure sensor. On acceleration, the EPR is deactivated, but if the valve sticks, it will cause the above symptoms. You may or may not be able to duplicate the concern, since it normally only occurs on initial start-ups when the PCM activates the EPR for prove-out. If you are able to duplicate it, inspecting the position of the EPR linkage can confirm the problem (the servo linkage will be extended and the bell crank tang will not be on its stop). To repair, replace the turbocharger pedestal.

A similar condition can occur if the EBP sensor tube plugs up with carbon, causing the PCM not to see an increase in exhaust back pressure resulting in the PCM not deactivating the EPR solenoid. Remove the tube and inspect for blockage. Clean as necessary.

Some Powerstroke trucks may exhibit codes related to keep alive memory--KAM (P0603); or read only memory--ROM (P0605). P0603 may be set if the batteries or computer are disconnected. On the 7.3 P0603 can be cleared by running the engine for at least 30 seconds, then clearing all codes. For the P0605 the computer should be reprogrammed with the latest available calibration. Broadcast Message 1076.

 

It's not acting like ucvh I visually inspected the driver side pulled the cover and watched all injectors oil and unplugged each one to see if one didn't change the idle any, they all did.

I ohmed the passenger side all injectors ohmed 4.5 to 5.0
And the pings and plug did not look burnt but have not pulled the cover on the passenger side

The EBPV is not closing.
The icp and ipr show good on the pressures and duty cycle
I didn't figure ebp sensor would cause rough idle and lower than normal power.

There is some oil residue on the icp plug but it's not full of oil and the ipr still has then tin nut on the back.

Also it's about 100 degrees here in Texas so far from the pcm to tell the EBPV to close unless there was a messed up sensor but it is not closing.

 

And the batteries were disconnected and the comouter was removed to work on the parking brake yesterday

 

wrong reading of EBP can effect power and shifting in an automatic


my EBP tube was plugged up solid and ran much better once replaced


Some clean with a speedo cable and solvents but after an hour of trying I bought a brake line and bent it to fit.

 

Forgot to mention this is a manual transmission

 

What is the EBP reading, KOEO?

 

It's at 21 while Koeo

 

That's the cause of your P0470. Anything over 18.5 during a KOEO test will set that DTC. You may have a plugged tube, biased sensor or a problem with the wiring or PCM.

 

Would a plugged ebps cause a slight rough idle and a slightly longer crank time to start same time hot or cold?

 

Probably not, unless the sensor is actually shorted internally and dragging down the VREF signal. I don't think that's the probably the case, but it can't hurt to monitor VREF along with ICP and IPR duty cycle while cranking.

 

What should VREF be while cranking? I know icp needs to be at least 500 and the ipr should get abover 64% IIRC

 

VREF is supposed to be a constant 5 VDC. It's the reference voltage nearly all the sensors use.