They are electronically activated, so yes, that would be the case. Unfortunately, the circumstances around a "runaway" motor are that it isn't running away on diesel fuel, but instead it is sucking down and burning it's own engine oil.

The reality is that IF the engine is somehow able to ingest its own oil (The CCV is a big problem point in this design) then it would not be able to do it without air as well. Simply shutting off the engine will NOT be enough to stop it, IF it is consuming enough oil to make this run away.

The problem is - Where will the oil get into the intake, OTHER than the CCV or turbo? Plainly, several members here have ALREADY had catastrophic turbo failures. I'm one of them, the turbo shaft snapped in half and the engine promptly pumped most of its oil OUT through the broken shaft into the exhaust. As the turbo needs oil for cooling, not just for lubrication, I would suggest that the chances of the oil arriving on the intake side are remote. More oil is delivered through the turbine side than the compressor side.

As for the CCV, if your engine is properly filled with oil (not necessarily "full" on the dipstick!) then the CCV will not be passing massive amounts of that excess oil out to the intake OR an EHM. But no matter what, if you have an EHM, you cannot have a runaway from the CCV. Period.

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Proud supporting vendor of LOST Jeeps
TRAVELING CRD TECH. I come to you!
Need help? Just ask! I've taken it apart more than most.
Email jeep [at] maincomputer [dot] com - BOARD MESSAGING IS BROKEN
Over 225 CRDs currently driving with my valves, timing belt, rockers, or ARP Studs.
Bad noises = REALLY bad things.

And that crankcase oil that is used for fuel usually comes from a blown turbo. With almost unlimited fueling, one of the ways to kill the engine is to choke the airsupply to the engine.

So they detect failure buy measuring the resistance across the motor and light the CEL if it is not in range? Wow, I thought for the price they charge for these suckers there would at least be proper positional feedback from the valve. I guess I can just disconnect the motor and replace with a suitable resistor then?

Is it common for the gears fail long before the motor? I've noticed rougher shutdowns often, long before the CEL, but having cut my teeth on 80's and 90's diesels the shutdown shudders are part of the experience so I never thought anything of it.

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http://www.thermalproducts.com/attachme ... ngines.pdf

It is a legitimate concern in certain industries.

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2005 sport crd-SOLD No regrets

Yes... not ours.

That is a very good product to have, IF you are operating a diesel in the presence of "flammable hydrocarbon vapors" as that ad clearly states. This only furthers my point - For our engines to runaway, they need to have a considerable alternate supply of fuel, such as the engine oil. The chances of that are exceedingly remote in the light-duty transportation market that our CRDs were produced for.

I'm not saying that we shouldn't have some form of a shutdown valve like that, what I am saying is that WE DON'T have one now. Follow the controls of the engine through to their logical conclusion. If the FCV is only capable of being energized when the computer wants it (forgetting about the SEGR for the moment)... Then the computer would need to know about an overspeed condition in order to believe that there is a problem. Is there an overspeed sensor? Doubtful! I know for fact that the turbo doesn't have one, which is a possible reason why my own turbo failed - I didn't know it was being abused by either a faulty MAP sensor or a cheater chip.

The engine does have a TPS of sorts, but it is on the go-pedal b/c we have a drive-by-wire system. The computer knows to cut the fuel supply when we take our foot off (of course) but would it close the FCV if the engine didn't respond? I don't know. That would be a question for GDE, as they are the only ones to have gotten that deep into the code. I'm inclined to think MOPAR did not design the FCV with that function, as the earlier 2002-2005 CRD (basically the same vehicle, sans emissions) did not have an FCV at all.

Ditto for the earlier VW TDI designs - Before the 99-04 engine models, the diesels didn't have any "anti-shudder-valve". It was added for emissions nonsense, nothing more. Just think... What if the VW book-writing department decided to call it an "anti-shudder" valve because they KNEW from experience that owners would do anything they could to remove / disable the power-sucking emissions devices on the engine? If they named it as a direct part of the EGR, people would be very likely to screw with the device, even if they left the EGR functioning. That would then reduce the effectiveness of the EPA's "lets kill the diesel with power-sucking-longevity-sucking soot-integration devices" program. Its all about the emissions, and keeping those devices installed and active. Why else would they have added the CEL check programming to use the MAF sensor to look for an airflow drop? The MAF isn't used for anything else...

Want proof of this for yourself, if you still have a stock (and not broken) FCV / EGR system? Here's a simple test. Yea, it will cause a CEL briefly, but that will clear itself in a couple cycles if you ignore it. Simply unplug the FCV itself, and shut your CRD off from an idle. Listen and feel how it sounds as it shuts down. For a thorough test, shut it off 2 or 3 times to get a good picture as to whether the engine changes how it stops.

Then plug the FCV back in, and do a couple more shutdowns, again watching and feeling how it stops. For me personally... There was ZERO difference. When my CRD stops, it stops. There is a fair amount of rotating mass to bring to that halt, but it happens quickly enough that I can't determine if it stops in 1/4 rev or less. Thats fine by me. How "smooth" do you want it to stop anyway? Its not an electric motor...

_________________
Proud supporting vendor of LOST Jeeps
TRAVELING CRD TECH. I come to you!
Need help? Just ask! I've taken it apart more than most.
Email jeep [at] maincomputer [dot] com - BOARD MESSAGING IS BROKEN
Over 225 CRDs currently driving with my valves, timing belt, rockers, or ARP Studs.
Bad noises = REALLY bad things.

I believe the FCV was designed to do three things:

1. Work with egr to make engine EPA compliant
2. Stop engine more smoothly
3. Cut off air flow in the event of a runaway when key is turned off.

#1 is the only thing that really matters to Chrysler but since it was there why not have #'s 2 and 3? All three are really optional to the end user as none are needed to get from point A to B.

Just for the record- My wife noticed right away when the fcv went out on ours.

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2005 sport crd-SOLD No regrets

The "TPS" as you call it is actually the APPS (Accelerator Pedal Position Sensor).

How does the engine know of an overspeed condition? I bet it doesn't. Sure it could look at the RPM, look at desired fuel(throttle) and see if it seemed high....BUT lets say you have manual in 3rd gear using your engine for engine brake going down a steep mountain pass, as far as the engine is concerned thats the same as runaway diesel, the same conditions happen to me when I downshift or kick it out of OD going down a pass or long hill, yet the engine does not kick in the FCV as a means to stop runaway diesel.






I am quite aware of this, and other people have made the same comment as me, so I am not alone in my assessment. With the FCV disabled I feel the very last ignition event as sort of a standalone firing......which gives the vehicle one last little shudder like someone was rocking it from the outside.

So yes it is noticeable without it, but only in a little minor way that doesn't seem to make any real difference. I don't see it as anything other than a small "comfort" device in that regard.

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http://www.Colorado4Wheel.com
"Its not about what you can DO with your Jeep, its about where you can GO with your Jeep."
Knowledgeable - But Caustic

It's possible, maybe probable, that the ECU doesn't close the FCV in a runaway condition. It's difficult to know without knowledge of the ECU's logic. That doesn't alter the fact that it commands the FCV to close when the ignition is off, and thus stops an engine in runaway mode if the operator turns the ignition off.

GDE's Eco-Tune retains Number 2. & 3 functions.

Yes the FCV does close during shutdown, and it could possibly stop a runway.....BUT closing the FCV at shutdown with low flow could be entirely different than closing at high rpm high boost. Do we know if the FCV is strong enough to close under those conditions? It partly depends on the design of the FCV, but IIRC its designed so that when it fails it fails open, which would mean its fighting an uphill battle to close every time it needs to close.

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http://www.Colorado4Wheel.com
"Its not about what you can DO with your Jeep, its about where you can GO with your Jeep."
Knowledgeable - But Caustic

Flow through a butterfly valve tends to close it due to dynamic torque created by the low pressure area behind the leading edge.

That small tidbit alone doesn't mean much. This is not a gasser where the valve is partially closed most of the time, the valve is always open and constricts during use. This indicates to me it is sprung into a normally open position. Meaning by default it is parallel to flow.......not any torque developed in that flow situation.

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http://www.Colorado4Wheel.com
"Its not about what you can DO with your Jeep, its about where you can GO with your Jeep."
Knowledgeable - But Caustic

The degree to which the butterfly valve is self-closing with flow depends on the location of the disc shaft. Assuming that it's located at the disc's center or lower, the valve motor only needs to overcome spring torque and it is assisted by the flow through the valve. So the contention that increased flow through the valve due to a runaway might prevent it from closing is puzzling.

1000s of scary stories about the possibility of it happening. You have a better chance of getting in an accident or having the timing belt come loose with your CRD then getting a runaway engine.

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20 year owner of Libby CRD!
2006 LTD Bright Silver loaded with all the needed mods, CCV intact.
Equipped with HDS thermostat, plenty of heat, faster warm-ups, increased fuel mileage.