7.3 liter not running on all 8

[raftereric]

when cold in morning -- no skipping. when engine warms up it acts like I loose a cylinder or 2. could this be an electrical harness problem to the injectors under the valve covers --- I know from changing pre heaters I have 1 tab broken off of the 2 that hold the electrical connection to injector; or maybe something else?

 

[blacksnapon]

when cold in morning -- no skipping. when engine warms up it acts like I loose a cylinder or 2. could this be an electrical harness problem to the injectors under the valve covers --- I know from changing pre heaters I have 1 tab broken off of the 2 that hold the electrical connection to injector; or maybe something else?

That'd be the best place to start. The pass through harness has been a source of headaches for a long time on the 7.3.

 

[raftereric]

Thanks, I'll give that a look tomorrow. Do you know if the harness is a dealer item?

 

[blacksnapon]

Thanks, I'll give that a look tomorrow. Do you know if the harness is a dealer item?

Its valve cover gaskets.

 

[raftereric]

The valve cover gaskets are no more than 6 months old, I don't think it would be them but I'll check

 

[blacksnapon]

The valve cover gaskets are no more than 6 months old, I don't think it would be them but I'll check

Essentially, it's where the internal harness clips to the pass through connector on the valve cover gasket.

 

[d-kuzmen]

ISSUE:
On vehicles with a 7.3L direct injection (DI) turbo diesel engine, one or more of the following concerns may be present:

Rough Idle
Stalling
Hesitation/Stumble
Loss/Lack of Power
Poor Fuel Economy
Excessive Oil Consumption
These concerns may be caused by the injector cushion O-rings deteriorating, resulting in a poor seal. This condition cannot be detected with conventional diagnostics (i.e., it will not produce diagnostic codes with either Super Star or New Generation Star Testers).

ACTION:
Remove the injectors, check for deterioration of the cushion O-ring. If necessary, replace the O-ring with a new O-ring which has a more robust design and should not deteriorate under severe conditions. Refer to the following Service Procedure for details.

SERVICE PROCEDURE

If no Diagnostic Trouble Codes (DTCs) are found and normal diagnostics do not lead to a solution, remove the injectors according to the DI Turbo Service Manual.
Check for wear or deterioration of the cushion O-ring. If excessive wear is found, replace the O-ring with a new blue O-ring found in the O-ring Kit (F8TZ-9229-AA). Refer to the Instruction Sheet included in the kit.
NOTE: IF ONE O-RING IS REPLACED ALL O-RINGS AND SEALS MUST BE REPLACED. IF ONE INJECTOR SEAL IS SERVICED ALL THE INJECTOR O-RINGS AND SEALS MUST BE SERVICED.




The O-ring Kit includes the following:

One (1) Upper Backup Ring
One (1) Upper Cushion Ring
One (1) Upper Injector Seal
One (1) Seal
One (1) Lower Injector Seal
One (1) Injector Gasket
One (1) Instruction Sheet

PART NUMBER PART NAME
F8TZ-9229-AA O-Ring Kit


OTHER APPLICABLE ARTICLES:

 

[d-kuzmen]

Check the harness at the valve cover inside and out some times they come loose and give drivability issues, this will require to pull the valve covers off to check. Also check the driver side valve cover where the main harness touches the cover, unbolt the connector and look at the wires they like to chaff and short out cylinders.