Join Date: Oct 2009
Location: Vancouver, B.C. Canada
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$1400.00 included a full scanning of everything the Ficm, programing and instalation. It wasn't showing any codes using a snap-on code reader. I just heard from a buddies mechanic who sent me this, " Here is a list of symptoms that would make us suspect a problem with the high pressure oil pump:... Read More
a) rough idle when hot, but generally OK when cold, although it may idle rough when cold as well
b) a stumble (not cackle) when the accelerator is pressed firmly in the 1000 to 1500 RPM range
c) the engine has difficulty keeping a steady idle speed WITH THE HVAC SYSTEM TURNED OFF
d) long crank time in cold temperatures (below freezing)
e) lack of acceleration on initial application of throttle when engine is first under load. (We are verifying this symptom.)
f) lack of acceleration in the first portion of accelerator movement. (We are verifying this symptom.)
Symptom C is probably most telling of a pump problem, but still not conclusive. However, if the pump output is sporadic, the pressure will be sporadic in the oil rail and the ECM will constantly be adjusting the oil pressure, resulting in an engine that never idles at a set speed.
These symptoms are not definitive: for example IPR, injector or injector seal problems can cause symptoms that appear similar to a HP oil pump problem.
The Ford procedure for troubleshooting the HP oil pump involves running the engine on only one cylinder bank and swapping the pump outputs. Such a test does not isolate the problem to the pump as a bad injector or injector seals in either bank can foul the results.
At Diesel Research, we use the following method(s) to isolate a HP oil pump problem:
a) using a specially built tool, remove the IPR from the back of the pump and replace it with a specially machined IPR plug. The IPR plug plugs the HP oil relief provided by the IPR. DO NOT RUN THE ENGINE THIS WAY.
B1) install a manual pressure regulator set at about 500 PSI in the HP oil supply circuit
B2) using a special IPR relocation body, install the IPR outside of the pump body in the HP oil supply circuit.
In either case, route the regulator bypass flow into the oil fill tube on the passenger head.
c) start the engine. Remove the bypass hose from the fill tube and observe the oil flow. It should be relatively smooth. The bypass oil flow should be at least 750 ccs/ minute (99) / 1 liter per minute (99.5+). Anything less than this is cause for concern.
NOTE 1: some people will interject that one could have simply tested the pressure capabilities of the high pressure oil pump using some of the techniques outlined in the Injector O Ring article. Testing the pressure capability of the HP oil pump is not the same as testing its volume. Pumps may test fine pressure wise but not produce sufficient volume.
NOTE 2: The above test does not conclusively narrow the problem to the HP oil pump. Certain injector problems can cause injectors to use large amounts of oil and create what looks like a pump problem. The distinguishing factor is that such injectors will generally cause a bad hot start problem AFTER the first time the truck is put under load, but not necessarily before. (Don't ask how I learned that... )
NOTE 3: Some people may say their Powerstroke engines have good full throttle power and thus they have a good pump. Lubricating oil pressure at full throttle on a PSD is around 50 PSI, probably enough to push the pump pistons to the bottom of their bores. Good full throttle power does not guarantee a good pump.
A better test for a faulty HP oil pump is as follows:
a) using a specially built pump mount, mount the pump in a hydraulic pump test stand. The PSD HP oil pump is not a standard SAE mount: the oil supply is fed to the pump via a port on the face of the pump. Several other ports are needed as well.
b) supply the pump with a low pressure oil supply, a few PSI at most, but not low enough to cavitate the pump. Measure the volume pumped at a set RPM (350 RPM or so.)
c) increase the supply pressure and repeat the measurement in b). 50 PSI. Provided the pump was not cavitating originally, there should be no change in volume. If there is a change in volume pumped, it is likely that the pistons are not returning to the bottom of their stroke with the retainer plate.
There are several other tests as well, that should be performed on the HP oil pump if you've got it mounted on a test stand.
We've got another method for testing the HP pump, but it doesn't warrant explanation at this point.
Fixing the Displaced Piston Retainer Plate Ring
Our fix for the displaced piston retainer plate ring was to machine a sleeve that fit tightly in the bore of the swash plate cavity and yet did not interfere with the pistons. THIS IS NOT A TRIVIAL EXERCISE ! The sleeve sat above the piston retainer plate ring and held it firmly in its groove. The pump was run for a month and then disassembled and inspected. The piston retainer plate ring was found to be sitting nicely in its groove. The pump was tested for bypass volume in a running engine several times and found to be good.
We performed this fix because we wanted to prove that the low pump bypass volume at idle was caused by a problem within the pump itself. It is not economically feasible to perform this fix on a pump that is not operating properly. On the other hand, there is no guarantee that a new pump would perform any differently than a faulty one, because it too could be or could become faulty if the piston retainer plate ring slipped out of its groove.