You be the judge/jury - HPOP/ICP - which one is guilty?

[bluenavigator]

I mentioned this once before. The shaking only happens for very short time. That's why it is so difficult to pinpoint the exact source of the whole problem. I had noticed that it shakes for less than a second, just right before CEL light went out. Once it shakes, then it stopped as CEL light goes out. What I mean is that CEL light was on from the point that I started the engine until the engine shakes. CEL didn't go back on again after that. The engine had shaked maybe one or twice during I am driving on the road. That's what leads to my suspecision of high pressure oil pump or ICP but I won't know which one for sure. That's why I posted the pressure output readings. So that gives clues to the problem. Seem that it is normal because I don't know the normal range of operation from HPOP. Nobody said "ohh that is too low" or "that is normal, it is something else."

I had replaced the burnt wirings inside the valve covers. I had seen how the CEL behaves with that problem. The CEL fllicks on/off and engine shakes much worse.

I know that CEL does give out the codes. The ford dealership's service guy said that the paper shows no codes but just quoted "ICP Circuit Malfunction" and it stated that ICP sensor and ICP connector are recommended to be replaced. I have OBDII tool but it can't pull the codes from my truck because I was told that my truck doesn't have "true OBDII" system and the computer has to be reprogrammed to be full OBDII. I don't know what the heck they are talking about because I have OBDII socket under the dashboard on passenger side. Also, I was told to check other socket inside the engine area, near brake booster. I couldn't find that one at all. Nada. You are welcome to come to find that one. It isn't there at all. Yeah, it bothers me a lot that I couldn't find the solution.

So far, it seems that I have to shell out 200 bucks for ICP and find the answer. Problem - I can't return the ICP part if I opened the package. If ICP sensor isn't the problem, 200 bucks went down the toilet, which I don't want to do. I would like to save some money by go to Longhorn International on Airport Blvd but I don't have car to drive out there.

[bigred350]

This sounds a little like the problem I am having with my truck. I do not get A cel light. I have changed the injector o-rings and installed a new ipr. no help on the ilde I am suspecting the icp but do not what to keep putiing parts on it and having no help. When I pull my connector on my icp my engine dies? any way to test this sensor? I need help to.

[action4478]

Originally Posted by bigred350

This sounds a little like the problem I am having with my truck. I do not get A cel light. I have changed the injector o-rings and installed a new ipr. no help on the ilde I am suspecting the icp but do not what to keep putiing parts on it and having no help. When I pull my connector on my icp my engine dies? any way to test this sensor? I need help to.

Unplugging the sensor ,,the engine should keep running ...



You need a minimum of .83v for starting (that would be about 500 psi). At key on, you should get a .25v to .4v signal. Operational range for the sensor is .65v to 3.25v. Some approximate pressures compared to voltage signal would be:
500psi = about .85-.87v
1000psi = about 1.4v
1800psi = about 2.3v
2400psi = about 3v
3000psi = about 3.8v
The sensor screws in, so you can't depend on orientation of the sensor for the pin locations. But you did find Vref where you read the 5V.

If you hold the ICP connector looking into it with the latch on top, the left pin is Vref, center is ICP signal, and right is Signal return. The corresponding wire colors should be brown/white, dark blue/light green, and grey/red.

[ford_doctor]

Originally Posted by bluenavigator

You be the judge/jury - HPOP/ICP - which one is guilty?

My judgment is that you are guilty of not repairing your truck based on the diagnosis that you paid for. According to the information in this topic, you brought your truck to a dealership where you requested and paid for a diagnosis of your concern. I question why you apparently declined to have the recommended parts replaced? If we assume for the sake of debate that the diagnosis is accurate why have you not made the recommended repairs?

Secondly, I fault the dealership for not providing to you with a complete diagnostic report in writing which should have documented the DTC's (diagnostic trouble codes) retrieved from your PCM and the results of any pinpoint tests performed. After all, YOU PAID THEM FOR THIS DIAGNOSIS! When I perform a diagnosis for a customer I document that I verified the concern, all relevant diagnostic information including DTC's and test results regardless of whether or not the customer approved or declines the necessary repairs... which brings me to the third part of my post.

If you had this information you would be able to post it here which would be very helpful to the knowledgeable people trying to assist you. If I read between the lines and take a few quotes from your posts I suggest that the recommendation to replace the ICP sensor and the harness connector was the proper one.

"ICP Circuit Malfunction" tells me that there is an intermittent fault in the ICP circuit that is causing inaccurate fuel control and your rough running. The check engine light is consistent with an ICP circuit related code. My guess is the DTC's being set are either a P1280 and/or a P1281. A failing ICP sensor or a poor connection at the harness connector are the most common failures with this particular concern. Since this is very intermittent and therefore difficult to diagnose, replacing the sensor and connector would be your best option because the information that you DO have points to a circuit issue.

Good Luck!

[bluenavigator]

Originally Posted by bigred350

This sounds a little like the problem I am having with my truck. I do not get A cel light. I have changed the injector o-rings and installed a new ipr. no help on the ilde I am suspecting the icp but do not what to keep putiing parts on it and having no help. When I pull my connector on my icp my engine dies? any way to test this sensor? I need help to.

Look at the first post (look below) that I posted. My engine was running without ICP, not dying at all. The ICP was sitting on my shop bench. It does give out HPOP pressure measurements. Actually, what was happening, the controller was guessing the pressures and give out voltages.

Originally Posted by bluenavigator

Somehow, I was so busy and didn't get chance to redo the diagnios on my truck. I had posted the issue on my truck. Armed with new oil pressure gauge, I pulled ICP out and put the oil pressure gauge in the ICP's hole. I changed the oil. The oil was ruined with brake fiuld that I accidently poured in the engine. I drained and left it draining all the day. The oil stopped dripping, leaving strange gummy oil - bad oil or that was result of adding brake fuild to the engine oil? I just hope that 1/2 cup of brake fuild doesn't have much effect on the engine. Anyway, I recharged the batteries since the truck wasn't started over 2 months. The engine started on first try, which is good news. I watched the high oil pressure gauge as I rev'd the engine. I recorded the results.

The results:

600 rpm - 600~650 PSI <--- idling speed
1000 rpm - 650~700 PSI
1500 rpm - 700 PSI steady
2000 rpm - 800 PSI steady
2500 rpm - 1100~1250 PSI (tried to keep engine reving steady)
3000 rpm - 1400 PSI (able to hold the engine reving steady)

Are the results good? The ICP is out of the engine and sitting on the work bench in my garage. Pretty much that it tells you that ICP isn't plugged in the system. Do I need to retest this with ICP out but plugged in the system? Let me know which part is the guilty party.

Anyway, I guess that I will check all the wirings from ICP sensor plug to the harness and follow it to the end. It should lead to the engine controller module, right? If not, where should the ICP sensor harness lead to then? IDM?

[ford_doctor]

The ICP wiring connects to the ICP sensor and the PCM. A common area for wiring concerns is at the left valve cover where the engine harness droops down over the valve cover to the fender well. The harness has been known to chafe on the valve cover.

When the PCM loses the ICP signal it uses an "inferred" signal.