9 Common Problems With 7.3 Power Stroke Diesel Engines, And How You Can Fix Them

7.3-Power Stroke Diesel Diagnostic Sensors

The legendary 7.3 Power Stroke Diesel engine, when properly maintained can provide years of trouble free service. However there are several common problems that can develop over time. Generally speaking these can all be resolved relatively easily. Listed below are 9 common problems of the 7.3 Liter Power Stroke Diesel engine, in no particular order.

7.3 Power Stroke Diesel Common Problem #1 : Causes No Start : 

Injection Pressure Regulator (IPR) Valve, located in the valley on the High Pressure Oil Pump (HPOP). These can stick, seals get damaged, have the sensor go bad or the wires get damaged. Locate the IPR Valve, check for loose or damaged wires, check that the tin nut on the back of the IPR sensor is tight. When reinstalling the IPR unit torque the IPR to 35ft/lbs and do not use sealer on the IPR threads, as there is an orifice in the threaded area which the sealer could plug.

Rebuild IPR Valve from $14 or replacement part number F81Z-9C968-AB.  Cost $140-$300 for new.

7.3 Power Stroke Diesel Common Problem #2 : Causes No start : 

Injector Driver Module (IDM), located on drivers side fender. These can go bad or get damaged from water and will cause a no start or rough running and cut outs in revving/rpm. Check for damaged wiring, moisture or water intrusion. Be sure to check your specific IDM part number as it is engine specific. For 99-2003 F-Series Pickups and E-Series Cargo van,  IDM 120, includes part number: XC3F-12B599-AA. Replacement cost $50-$350 for used-new. 

7.3 Power Stroke Diesel Common Problem #3 

Cam Position Sensor (CMP). Can cause the engine to cut out and eventually die. Making it not start until it sits or is reset on the batteries. An easy way to make sure yours is good; on the Old Body Style (OBS), check if your tachometer moves while cranking, if it does your CMP is good, If not replace. Cost $24-$70. Don't buy the generic sensors from any parts store, get an OEM Cam Position Sensor, part number F7TZ-12K073-B, because some aftermarket CMPs can be defective out of the box. Keep known good a spare in your glove box.

7.3 Power Stroke Diesel Common Problem #4

Under Valve Cover Harness (UVCH) Connectors, when these come loose or get shorted they can cause rough running conditions to the point where the truck sounds like it has 17* timing and it lopes bad and will often die and sputter. An easy way to fix this or check for it, there are four connectors on your block / heads that are under the valve covers unplug them and check for cut wires, loose or burnt connectors, if they are burnt or damaged, replace them. It's a simple fix. The entire valve cover gasket kit with connectors, part number F81Z-6584-AA, can be replaced for $100 or less.

7.3 Power Stroke Diesel Common Problem #5 

Clogged fuel filter. A restricted fuel filter will often cause long cranking or a semi-loss of power, if the injectors can't get the fuel they need. Replace fuel filter. Part number F81Z-9N184-AA. Replacement cost $9-$30.

7.3 Power Stroke Diesel Common Problem : Causes No Start #6 

Lift pump failure, this will definitely cause a no start. One way to rule this out is to check the fuel bowl for fuel before and while cranking. If no fuel is in the fuel bowl, fill the bowl up with clean fuel and if it starts replace the pump. Part number F81Z-9C407-AC. Replacement Cost $125-$320

7.3 Power Stroke Diesel Common Problem #7 

Overheating. This could be related to the radiator, thermostat, water pump, cooling fan or bad coolant. Cost for thermostat could be $12-$30. The main issues are often the thermostat or water pump, part number F81Z-8501-FA. $120-$250 for one of those. Both are fairly easy to replace.

7.3 Power Stroke Diesel Common problem #8

Injector control pressure (ICP) sensor. Causes the engine to run, but cut in and out and really roughly throttle. Check for oil in the ICP connector, if present, ICP is bad or on the way out. You can verify better running by unplugging the ICP sensor, temporarily, to see if the issue goes away.  Cost $65-$167. Part number F6TZ-9F838-A.  If oil has permeated the wires, It is recommend to replace the ICP sensor pigtail as well. 

7.3 Power Stroke Diesel Common Problem  #9

Fuel heater. - The fuel heater can short out and blow maxi fuse #22, disabling the PCM. Disconnect the fuel heater, replace fuse, re-try start. Replacement cost about $3 for the fuse (always carry spare fuses, including maxi fuses, in the glove box)