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Marc, Technician, Auto, Diesel
Category: Ford
Satisfied Customers: 1888
Experience:  32 years exp. Automotive repairs on Ford cars and trucks
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2002 Ford F-350: with 7.3 diesel the left bank on engine will not fire

Resolved Question:

2002 Ford F-350 with 7.3 diesel the left bank on engine will not fire. Where would I start intrying to figure out why? Also give me the steps in tracking down the problem
Submitted: 10 years ago.
Category: Ford
Expert:  Marc replied 10 years ago.

Inspect the left hand, under valve cover harness for damage or being burnt in the connector. Repair as needed and install the retaining clips, prevent future problems of dislodging. Inspect the connector C138 (42-cavity) on the left rear of the engine for damaged or burned terminals and repair as needed.

Should 2 or more injector driver circuits become shorted, damage to the Injector Driver Module (IDM) is likely.

Customer: replied 10 years ago.
Reply to Marc's Post: I have checked the wiring harness on left bank for burns and breaks, and checked continuity and all is ok. I checked for pulse signal to see if power was getting to injectors it was not so I changed out the injector module thinking that the module was bad for the left bank. After I did that I got power to the left bank,but still the same problem. Not sure if I'm going in the right direction!
Expert:  Marc replied 10 years ago.
Is the check engine light on? Did you check the wires under the valve cover.
Customer: replied 10 years ago.
Reply to Marc's Post: Yes I did a continuity check on the wires underneath the valve cover and checked for breaks and burnt pins it allchecked out ok. I checked seperate from the outter plug and also plugged in to the outter plug.
Customer: replied 10 years ago.
Reply to Marc's Post: Yes I did a continuity check on the wires underneath the valve cover and checked for breaks and burnt pins it allchecked out ok. I checked seperate from the outter plug and also plugged in to the outter plug.No the check engine light is not on.
Expert:  Marc replied 10 years ago.

When the engine is cranked over,
crankcase oil pressure builds. In addition
to lubricating all of the engine's internal
moving parts, the oil has one more path to
follow. It travels through the timing cover
to a high-pressure injection reservoir
mounted on top of it, used to supply oil to
the high pressure oil pump. This pump
then increases the pressure to the high
levels needed to pop open the injectors,
and to increase the pressure of the diesel
fuel entering the cylinders for complete

The oil pressure increase is
accomplished by a solenoid similar in
function to an Idle Air Control valve. This
solenoid, the Injection Pressure Regulator
(IPR) is duty cycle controlled by the
Powertrain Control Module (PCM) to boost
the oil pressure to the levels needed for
good performance.

The oil then flows from the pump
through braided steel lines to the center of
each cylinder head where it runs through a
central galley next to the injectors.

When the powertrain control module
(PCM) determines which cylinder needs to
fire, it electrically energizes a solenoid in

the injector to allow the high pressure oil to
enter, intensifying the pressure of the diesel
fuel and injecting it into the cylinder. The
PCM uses an Injection Control Pressure
sensor (ICP) to determine what the oil
pressure is. The sensor is mounted in the
inside face on the driver's side. The more
ground time applied to the IPR, the higher
the pressure rises. The minimum amount of
pressure needed to open the injectors is
400 PSI. With a pump designed to put out
well over 3,000 PSI, the PCM should be
able to achieve that pressure with no more
than a 12% duty cycle on the IPR. If the ICP
indicates pressure fails to reach the
minimum value, the PCM continues to
increase the duty cycle on the IPR until it
reaches the maximum of around 60%.
Somewhere around 50%, even if adequate
pressure is achieved and the engine runs,
the PCM sets a code for ICP above/below

The first step in diagnosing a fault
in this system simply requires checking
the oil level in the crankcase. If the oil level
drops three quarts or more, it lowers the
level in the high pressure reservoir,
reducing pressure in the injection oil
system. Once oil level is verified, watch the
engine oil pressure gauge on the dashboard
while cranking to verify that it jumps to the
middle in a short amount of time. In real
life, this ‘gauge' is an IDIOT LIGHT with a
needle. It uses a normally open switch
instead of a true sender. When engine oil
pressure exceeds 5 PSI, the switch closes,
completing a path to ground for a voltage
applied through a dropping resistor in the
gauge, causing the needle to jump up. This
switch is located in the top of the high

pressure reservoir. If engine oil pressure for
any reason is low, it will need to be
addressed first as insufficient high pressure
will result. If it is OK, monitor the RPM, ICP
and RPM PIDS in the datastream with a
scanner. Upon cranking, at least 150 RPM
should be noted. The PCM then activates the
IPR to build pressure. If the IPR reaches the
max and under 400 PSI is showing on ICP,
or you see a reading of 2,000 to 2,500 PSI,
(a default reading generated by the PCM
when it believes the sensor is in error) and
the engine doesn't start, there is a fault in the
high pressure system.

To isolate the heads as a potential large
leak, 1) Remove the line from the right head
and cap with a suitable plug. 2) Remove the
left hand line and adapt an oil pressure
gauge capable of reading 3,000 psi or
greater to it. 3) Crank the engine while
watching the gauge for actual pressure. If the
reading is low, the problem lies in the high
pressure pump or the IPR. But to determine
which is the guilty culprit, you first need to
replace the IPR to evaluate. If that doesn't
correct it, the pump will need replacing.

So the next time one comes in with a lack
of power, stalling or no start concern and
you retrieve fault codes P1211 and/or
P1212, you too can work a little MAGIC!

Marc and 6 other Ford Specialists are ready to help you
Customer: replied 10 years ago.
Relist: I still need help.
marc i checked the oil pressure at the high pressure oil pumpit reads 3800 psi is that to high for starting. wood the ipr being faulty cause this reading
Expert:  Marc replied 10 years ago.

Does the engine run right once it warms up??



The injector pressure regulator controls pressure for both heads .

I'm still thinking electric did you try the engine with the valve cover unbolted.

Just because there was no shorts in the gasket harness when you checked it unbolted. I'm thinking the short may only be present when the cover is tight.

How did you get that 3800 PSI reading ? Was the pump dead headed? (gauge hooked up directly to pump no bypass). Your problem would come more from low pressure on one head (left).

That may be a good pressure reading I'm still trying to find a real would value for that reading.

Customer: replied 10 years ago.
Reply to Marc's Post: ya ive trided to start it with the valve cover off with no change and i got that 3800 psi by capping the ss line on the rt head and putting a guage on the ss line for the left head is that right . would the injecters get damaged with to high of a psi and doesent the ipr regulate befor the lines go in to the heads.
Expert:  Marc replied 10 years ago.
Yes IPR is in the High pressure Resivoir. Your next step is to get the engine on a scaner to do an injector buzz test Not if there are any week injectors Check ICP pressure reading Cranking As describrd in artical above.
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