1995 Ford Explorer Fuel Pump Control

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I figured you'd do that.
A hall device is nothing more than a piece of thin metal or semiconducting material ( conductor ) It has an electric current applied to it. With a magnetic field around it electric charge tends to be pushed to the side of the conductor and is measurable. The hall effect discovered in 1879. An over simplification but that is it in a nut shell. I'll assume you are familiar with how the hall device or pick up if you want to call it; in the ford distributor looks like? Where is the magnet? What is it attached to? You will notice the magnet field is either all ways around the conductor or is shunted away depending on weather a window or vane is between the magnet and conductor.On this device the distance of the magnet never changes so the field never changes. The supply voltage never changes. The output is dependent of the magnetic field supply voltage and conductor. The conductor has no supporting parts like transistor, capacitors so there is no chance of some kind of "feed back". It's just a thin piece of metal or silicone material. That being said there is nothing that will change the out-put but the rotating vane wheel.
Now I'll assume you want support to those statement?
http://en.wikipedia.org/wiki/Hall_effect http://www.eeel.nist.gov/812/effe.htm http://www.tf.uni-kiel.de/matwis/amat/mw2_ge/kap_2/backbone/r2_1_3.html
Thats as far as I'll go, wnat to lean more, do your own reasearch. That little tid-bit in your Ford lessions will not cut it.
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quote from that article:
Hall effect devices produce a very low signal level. To apply this requires amplification. While suitable for laboratory instruments, the vacuum tube amplifiers available in the first half of the 20th century were too expensive, power consuming, and unreliable for everyday applications. It was only with the development of the low cost integrated circuit that the Hall effect sensor became suitable for mass application. Many devices now sold as "Hall effect sensors" are in fact a device containing both the sensor described above and a high gain integrated circuit (IC) amplifier in a single package /quote
Man... I thought I was arrogant!
But I know my electronics, chump!
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wrote:

Who said you did or did not. You did argue though the hall device is more than it is. Sp Krusty, if you know so much about electronics whay do you make such an argument?

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And It IS more than you say it is!
Let's make this perfectly clear!
The Hall Effect theory is a given, we can take the presence of gaussian elements used with them, and the magnetic properties therein, for granted, assuming they are properly positioned... quit dissembling!
The Hall devices used in automotives contain solid state thin-film processing circuits consisting of a number of transistors and associated components.
Yes or NO!
Dont give me theory, dont give me anything but yes, or no!
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wrote:

Let's put the ball in your corner, prove it is.

You have too. Look at how the damn thing is made. Then think with your brain instead of emotion. Bob states that this device created a roughly a 900 rpm signal yes? Lets explore that first. This hall device is a metal strip, not any type of micro circuit it's just a dumb piece of metal with three wires attached. The magnetic field is made by a permanent magnet that is attached to the hall sensor via a very stout piece of formed steel making both the sensor and magnet always in alignment. That alignment can not be changed unless there is massive damage to the distributor. He made no mention of damage, if fact he said he just replaced the "pick up", not the whole distributor. If you are even remotely familiar with Fords "pick up" you know what I'm talking about. So this is not theory it is fact, just as I spelled out to Bob the magnetic field can not change. The supply voltage can not change. As I told you; and Bob if he goes back to basic training on the TFi ignition system it is clearly spelled out that the TFI module is the amplifier for the hall voltage. This hall device is a dumb device, NO CIRCUITRY involved. Now he claims to have seen with the key on and the engine not running a pip signal of about 900 RPM. How did he determine 900 RPM. I'll bet he will say that on the SBDS display on the PIP line it said 900 rpm. Fair assumption? I would say yes. Why? if the so called RPM was not displayed he would have to do math and actually count each square wave. Why? How is a "defective part" with a "failure" like this going to give a constant enough pattern for a processor that only counts 1 very small part of the square wave? Do you know what part the is? It's called cylinder one identification. Do I need to explain what the PIP signal looks like and what #1 ID looks like? I'll assume your emotions are in check enough to say no. So we have a device with no outward signs of damage, so the magnetic field has not and is not changing. Supply voltage is constant. The conductor is just a thin metal strip. There is no amplifier in the device it self, well documented via Ford. How is it possible for this device to create a signal that is good enough for a computer to look at it as a good enough signal to fire injectors ( which Bob said did happen ) and looks like a normal square wave on a display? Lets say the wire that picks up the hall voltage has a poor contact. Ok, lets explore that possibility. The magnetic field on this device is arranged so that when the field is shunted the hall voltage is high. So, distributor has to have stopped in such a position so that a vane is between the hall sensor and magnet. Now that contact will have to vibrate or go open closed 3240000 per second. Damn tall order. Next what would that look like on a scope? Will it be a nice square like a normal square wave would look like? No. Because this is a mechanical connection there will be trailing voltage, go back to points, why did electronics replace points? Electronic on and off is damn near instant, a mechanical on and of is not and is VERY visible on ANY scope, including SBDS. Now; The engine processor and SBDS will only calculate RPM by counting the #1 cylinder ID per second, millisecond what ever time frame the software is using. Your telling me that this failure that you want to call "feed back" is going to produce a square wave that is uniform with 1 short wave that is uniform enough to come up with a RPM number? I don't think so. That is as much a stretch as saying a generator will produce voltage when it's rotating parts are not rotating.

As I said before NO period. Prove there are circuits in that device. Don't just insist, prove it. Have you ever dissembled one? Looked at it under a microscope? Been to a training course or electronics seminar on Fords hall device? Seen the schematics? Yes or no!

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Cock fight still not over ????????
How do you want prove his dick is bigger then yours
it is a news group, not an university class you are attending
tjesus, get over it
wrote:

granted,
brain
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theory
change.
to
the
dumb
PIP
this
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constant.
device
looks
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tall
mechanical
the
so.
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Yea, but my dick IS bigger ;-)
wrote:

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{REST of bloviating BS removed}
I dont give a shit if it says that 100 times in the Ford manual!
Dumb devices DO NOT NEED POWER
A Hall effect sense element (as opposed to device) produces a miniscule signal that MUST be amplified! You cannot feed a signal like that into a low-impedance circuit Look at the TFI > pickup circuit tests here:
http://tinyurl.com/8gtwm
scroll to ICM test
Hall effect tech was not used in cars until circuits could be built on a substrate... which just happened to coincide with use in other circuit production
Now.. if you took a dist and removed the TFI, then applied 5v and COMMON to the power pins, the pip lead would AT LEAST drive an analog meter.
Pretty freaking good for a DUMB device... I'd bet you could barely discern a signal with a 10 megohm scope set to highest amplification if it were just the hall sensor plates in there.
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wrote:

Really? Then why does a relay need power to work? No supply no ground no work. A resister can not drop voltage if there is no voltage and current flow? Dumb devices.

Are you sure, have you done so?

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wrote:

Have you? Are you saying it will NOT drive an analog meter? Bob
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I dont HAVE to... my background in electronics, and the expected ohmmeter readings on the ICM test for the pip input, tells me all I need to know.
It's called 'impedance', you can couple a low impedance source to a high impedance input, but doing the opposite will swallow the signal.

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If you insist.. substitute 'active' for 'dumb'.
A relay DOES need power, thus is 'active'.. a resistor does not, thus is both dumb and passive component.
A relay is, for all intents, an amplifier in most applications... a resistor's purpose is to reduce amplitude or voltage by means of limiting or shunting current.
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We are already looking at the ignition side of the system.
The fuel pump... which you CAN HEAR.. is the symptomatic tell-tale.
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The fuel pump may very well be on. But if the one way check valve in the pump failed and allowed fuel to leak back the lines would be empty. Or if the pump is failing and not delivering the required fuel volume you still have a crank no start. That two second fuel pump run would not provide enough fuel to pressurize the line thus a crank no start situation. Two or three key cycles would. A gauge would prove that out. Your ear is not telling you the health, only that it makes noise.

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DON, if you followed the advice and hooked up the fuel gauge and verified that a fuel pump does indeed put pressure on the fuel rail, maybe we can proceed.
Since, occasionally, the PCM is obviously not turning the relay off
And since the FP staying on coincides with the engine NOT starting, we might assume the problem has to do with a fault in either the PCM itself, or in the ignition-sense inputs.
We can rule out the FP Relay sticking and, also, the drive circuits for that relay because the engine doesnt start.
I ASSSUME no codes were stored and that makes it even odder.
So the next time it wont start and FP stays on, open the hood and listen closely for any odd sounds and try to locate them.
While under hood in that case do a gentle 'tug-test' on the wiring harnesses around the engine to see if the FP stops
Also look up the harness to the CPS and find the connector.. I suppose there COULD be some odd occurence with the CPS being wacked that might not be stored as a code.
Another question: When you cycle the ign switch and the engine DOES decide to start does it start right up, or seem as if it might be flooded?

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A fuel pump relay sticking is not uncommon but on most Fords the pump will run until the battery is dead. If the pump shuts off with the key it can't be a sticky relay. Bob
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Dont interrupt the teacher!!!!
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<snip>

My Krusty, that's the same crap ol red seal hurricane pulls..................

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