Hey guys I've got a 2000 F350 7.3 (58,000 miles). A couple of weeks ago I was driving it and while decelerating to make a turn into a parking lot it cut off at @ 30 mph (at the time I was coasting with no fuel input or brakes). After I wrestled it to a stop it started right back up and I drove it @ 7 more miles to my home. Later that day I went to move it but it cut off right after I started it and it has not cranked since.

Now for the parts I have replaced trying to repair it ( new ipr, new cps, new fuel filter) I have no white fumes while cranking.. the tach shows @200rpm while cranking. The high pressure oil pump is full of oil and I have oil pressure while cranking. I have an Autoenginuity scan tool and can read real time sensor data. One thing I have noticed is the icp registers @ 200 with key on and @ 2800-2950 while cranking. I tried to perform an injector buzz test however it comes up with a P1668 PCM/IDM communication error. Other codes recorded were P1663 Fuel Demand Command Signal Output Circuit and P1667 Cylinder Id Circuit.

Any input would be greatly appreciated.

 

Welcome to the forum......
you might have bad UVCH harness, and or bad IDM.
check that connector inside engine bay with the 10mm or 8mm socket as far as i remember , its under fuse box, thats a connector for IDM.
now does your truck start now? if not you might want to look for blown fuse for IDM, and if you have one like that unplug you fuel bowl heater element.
hope this helps...

 

and since you have AE you can do injector buzz test. that will show if you have UVCH bad....( under valve cover harness)

 

The common issue with your codes seems to be lack of IDM power. As Pete suggested, have you checked the IDM fuse & relay to make sure they're good?

Edit: Welcome to FTE

 

and i forgot to mention do you get WTS light or not?

 

First can I say WOW, a 2000 with only 58K on the clock.

Second, I am betting on the fuel bowl heater blowing the PCM fuse.

Unplug bowl heater , change fuse and try to start.

 

After swapping the relay ,,if need be....

Some info from the manual



FJ1 DIAGNOSTIC TROUBLE CODE (DTC) P1670 and P1668

• DTC P1668 and P1670 indicates that a communication error has occurred between the PCM and the IDM.
• Possible causes:
  • Open fuse
  • IDM relay
  • Open or shorted IDM enable circuit
  • Open/short in EF circuit
  • Open/short in FDCS circuit
  • IDM powering circuits
  • PCM

If DTCs P1667 and P1663 are set together with or without DTC P1668, GO to FJ6 .


FJ6 CHECK IDM POWER

• PCM connected, IDM disconnected.
• Key on, engine off.
• Measure voltage between IDM connector Pin 14 and battery ground.

Is B+ present?
<TABLE cellSpacing=0 cellPadding=3 width="92%" border=1><TBODY><TR><TH width="50%">Yes </TH><TH width="50%">No </TH></TR><TR><TD width="50%">GO to FJ7 . </TD><TD width="50%">GO to NC6 . </TD></TR></TBODY></TABLE>
FJ7 CHECK IDM GROUND

• Key off.
• Measure resistance between IDM connector Pin 26 and battery ground.

Is resistance less than 5 ohms?

 

Thanks for all the input I'll check the items mentioned and post back.

 

Also does anyone think the icp pressure is to high while cranking (2900) ? Or could it be this high because the injectors are not opening.

 

Could be ..

Did you also monitor IPR DC% at the same time ?..

 

It kind of sounds like the IPR is closing to max % to build that kind of pressure while cranking.

Do you happen to have a buddy that has a 7.3?

Have you had much rain before this started to happen? It sounds to me like you either have a short, or your IDM took a dump. You might pull your IDM and see if it's got any water in it. If you have a buddy with a 7.3, stick your IDM in his truck and see if his truck will start with it.