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I got a Mustang GT 5.0 and it is hard to start when cold and when it starts up the idle is rough, not smooth, idle bogs and seems like it is going to die. Once the car warms up it runs ok. When I snap the throttle it does not seem crisp and smooth. The service engine light is on and I got a code 14, pip sensor. Does anyone know how to diagnose a bad pip sensor? What tests can be done to determine the pip sensor is bad?
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The profile ignition pickup (pip) sensor is Ford’s fancy name for a camshaft position sensor. It is located inside the distributor. If you got a code 14, the computer already diagnosed a bad or failing pip sensor. That code is correct 99% of the time. It is easier and a lot safer to replace the whole distributor than to just replace the pip sensor. Not to say it can’t be done, but there are a lot of chances to muck stuff up during the disassembly and reassembly of the distributor.
I ran the car again and it was hard to start but once it warmed up it ran great and the check engine light did not come on?? Is this an intermittent problem with the pip? Is this a common thing with the pip sensor? I don’t want to buy a distributor if the pip is not the problem. I checked the grounds and they are good. I do have a 5 volt reference from the TPS, and IAT..Another thing when the car runs and I turn on the AC, the engine slowly runs rough and sounds like it will die, and I turn off the AC it runs normal. Any ideas? Is there a test I can do to make sure 100% the PIP is bad?
[quote=”gnx547″ post=142981]Another thing when the car runs and I turn on the AC, the engine slowly runs rough and sounds like it will die, and I turn off the AC it runs normal. Any ideas? [/quote]
Check if the Idle Air Control valve (IACV) is working properly.Is there a test I can do to make sure 100% the PIP is bad?
There is. The computer has already done that for you, though, with the code 14. You can clear the code. If the sensor is bad, the code will return. If the code doesn’t return, it may have just been a glitch that caused it to set before. Also, you can check the PIP signal. You will need an oscilloscope to monitor the output of the PIP to check for clean waveform, correct pulse width, and proper frequency. You cannot test the PIP with a multimeter. You can also wait for the sensor to completely fail. You will know when that happens, because the engine will not start/run.
I borrowed an old Snap On Vantage scope and I hooked it up to the pip wire on the module and here are some pics of the waveforms. From looking at the wave forms, I think these are bad waveforms from the pip sensor? Shouldn’t the waveforms be a nice even square wave? From looking at these waveforms it tells me 100% that the pip sensor is bad and not producing a good signal?
[IMG]http://i62.tinypic.com/242v2wp.jpg[/IMG]
[IMG]http://i59.tinypic.com/25qxavt.jpg[/IMG]
[IMG]http://i62.tinypic.com/4ilcp5.jpg[/IMG]
[IMG]http://i58.tinypic.com/24xi443.jpg[/IMG]Yes, it looks like a failing sensor. The wave should be a lot cleaner than that. This wave is still ‘good enough’ that the engine will run, as there are still 12v peaks at regular intervals, but it will not run correctly as the timing will be affected due to faulty detection of TDC.
Here is a proper PIP output signal:
[quote=”gnx547″ post=144904]I’ve been thinking could it also be a bad TFI module causing the PIP signal to be week?[/quote]
That is a reasonable thought as the TFIs are notorious for causing issues. However I am skeptical that it would correct this particular issue since there aren’t really any other symptoms usually attributed to faulty TFI modules, such as crank-no start and random stalling.
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