Something new - Starting problem

oldnavy · **Posted:** Sun May 13, 2007 7:05 pm

Goglio704 wrote:

You can unplug the flow control valve while it is in the open position and it won't bother you again. The effect of this is very similar to the ORM and can be done in addition to the ORM or instead of the ORM.

One bad idea here unplugging the FCV, it does two things, one minor and one very important. It enables a quicker start and easier run by closing as needed to richen the mixture and prevent rattling jerky engine stops, but it also has another very important function. If you have a turbo seal blow out or hole a piston the big influx of oil will cause the "runaway engine" senerio and the only thing to stop that would be pop the clutch with the tranny in higest gear. The problem with that is we have no manual tranny in the US, only autonmatic, w/o the FCV the engine will self distruct and puke it's gut on the ground. Until you have ever experience a run away engine you can not imagine how scarry it can be trying to stop.

chadhargis · **Posted:** Sun May 13, 2007 8:07 pm

I can only imagine.

Goglio704 · **Posted:** Sun May 13, 2007 10:46 pm

oldnavy wrote:

Goglio704 wrote:

You can unplug the flow control valve while it is in the open position and it won't bother you again. The effect of this is very similar to the ORM and can be done in addition to the ORM or instead of the ORM.

One bad idea here unplugging the FCV, it does two things, one minor and one very important. It enables a quicker start and easier run by closing as needed to richen the mixture and prevent rattling jerky engine stops, but it also has another very important function. If you have a turbo seal blow out or hole a piston the big influx of oil will cause the "runaway engine" senerio and the only thing to stop that would be pop the clutch with the tranny in higest gear. The problem with that is we have no manual tranny in the US, only autonmatic, w/o the FCV the engine will self distruct and puke it's gut on the ground. Until you have ever experience a run away engine you can not imagine how scarry it can be trying to stop.

I am aware of the runaway phenomenon in a diesel, and I guess I should have mentioned it, but I was merely offering this as an alternative to completely removing the valve as the poster was contemplating. I agree that the FCV would be helpful for a runaway condition, but I don't view it as essential to have for that reason because it is not that common an occurrence. My FCV is plugged in. If relieved of its EGR duties by the ORM, I suspect a replacement FCV will live a longer life. I can understand the poster wanting it gone if it stuck closed. That would irritate me too. When mine failed, it stuck full open thankfully. Makes me wish there was an external visual indicator on the valve. It would be handy for troubleshooting and interesting to watch.

techTim · **Posted:** Mon May 14, 2007 12:27 am

"You can unplug the flow control valve while it is in the open position and it won't bother you again. The effect of this is very similar to the ORM and can be done in addition to the ORM or instead of the ORM."

oldNavy, Goglio, can you break this down for the less than proficient new diesel owner please?

am I correct in thinking that the FCV works like the throttle plate an a gasser, or am I way off base. how is this similar to the ORM, does it also disable the EGR?
please esplain for the lay-person.

dgeist · **Posted:** Mon May 14, 2007 10:02 am

Ranger1 wrote:

Try bleeding it as soon as it hard starts - if that clears up the problem, it would point to air getting into the fuel head.

So, I un-ORMed it and drove around yesterday to get rid of the CEL and got all my bleeding accessories ready for this morning's commute... and it started right up. No hesitation, no stall, etc. I don't get it, unless somehow a properly working EGR was the solution to the problem (which hasn't really been definitively diagnosed....).

yesterday, I tried unplugging the Flow valve while it was off just to prove to myself that the engine wouldn't start in that condition, but it did, which means it either it gets re-opened after vehicle shutdown or it got SUCKED open... I doubt that one. Anybody have the start-stop open-close chart thing for the FCV?

Dan

Goglio704 · **Posted:** Mon May 14, 2007 11:09 am

TechTim,

The FCV is very similar to the throtlle body on a gasser in form. In function it is totally different. It plays no part in keeping the mixture correct when the engine is running. Diesels are not sensitive to the mixture like a gas engine is and can run very lean mixtures.

On our CRD the FCV is there to

1: Restrict the intake and produce a vacuum during EGR valve operation in order to help the EGR meet its flow target.

2: Choke the intake on shutdown reducing the air available on the compression stroke and letting the engine stop smoothly instead of hammering to a stop on a compression stroke.

3: In the event of a runaway it would help a lot in shutting the engine down. (Runaway can occur due to mechanical failure that allows the engine to ingest and burn oil or if the vehicle was parked over a gasoline spill.)

4: According to Old Navy it may also restrict the airflow to richen the mixture for starting.

The EGR is disabled when the FCV is unplugged for largely the same reasons as with the ORM. Without the FCV, the computer can't manage EGR flow correctly and apparently doesn't try. Chessmaster seems to think that unplugging the FCV is not as good as the ORM. In his testing of unplugging the FCV, he found that the computer was still adjusting fuel delivery as if the EGR was functioning. He has gone a lot deeper with this than I have. I am in no position to dispute what he says. Hope this helps.

Goglio704 · **Posted:** Mon May 14, 2007 11:30 am

dgeist wrote:

Ranger1 wrote:

Try bleeding it as soon as it hard starts - if that clears up the problem, it would point to air getting into the fuel head.

So, I un-ORMed it and drove around yesterday to get rid of the CEL and got all my bleeding accessories ready for this morning's commute... and it started right up. No hesitation, no stall, etc. I don't get it, unless somehow a properly working EGR was the solution to the problem (which hasn't really been definitively diagnosed....).

yesterday, I tried unplugging the Flow valve while it was off just to prove to myself that the engine wouldn't start in that condition, but it did, which means it either it gets re-opened after vehicle shutdown or it got SUCKED open... I doubt that one. Anybody have the start-stop open-close chart thing for the FCV?

Dan

A healthy FCV is spring return to the open position when it is unplugged or turned off. On engine shutdown, it closes fully for 5 or 10 seconds, and then opens fully.

techTim · **Posted:** Mon May 14, 2007 11:37 am

this place is great, I ask a question here an it gets answered on this page and on the ORM thread too

thanks guys!

so if I read this right, leaving the FCV open will not allow low pressure to draw exhaust thru the intake? good for no soot but bad for stopping the engine smooth. does this throw a CEL? I think I will stick with the ORM for now, got used to the light last weekend and thinking about the clean air in the engine makes me smile. :wink:

again, this place is GREAT

Tinman · **Joined:** Mon Apr 10, 2006 10:45 am **Posts:** 308

I agree this place is great.

The FCV as a intake shut off for a runaway is a good idea, but it is just too rare to leave it there for that reason alone if it isn't going work. I'd rather hook up an emergency shut off switch and leave it open. There are a lot of diesels out there without any means to shut down a runaway. It's nice that in closes for a smooth shut down, but again not worth it if it isn't going work.

If it would work, ORM or not, I'd leave operational. But, as of now, I don't trust the stupid thing. It's not a BIG problem if it won't start because the FCV gets stuck closed, but it is just completely unacceptable that the thing might not start when you want it, and it has not started quiet a few times. I showed the wife how to fix it, but I don't want her trying to fix it somewhere far from home, in her nice clothes with someone waiting on her. I don't care if I get a brand new one and do a permanet ORM, I don't trust it. Unplugged it this morning.

oldnavy · **Posted:** Mon May 14, 2007 10:54 pm

You would be hard pressed to find a modern diesel running an auto trans that does not have a FCV, even most manual transmissions will have them. Remember we are talking modern high speed auto diesels and not low reving OTR or marine diesels. it is there for those two reasons listed, smooth stopping and prevent runaway. I remember reading in the FSM that it closes or partly closes on startup to assist in some function of the EGR start up I think, don't remember for sure and too tired to look it up.

nursecosmo · **Posted:** Tue May 15, 2007 12:08 am

I really can't notice any difference in shutdown between the FCV plugged in or unplugged. when I had my EGR replacement done at 20k (courtesy of DCX), the dealer also replaced the FCV because it was yucky from soot. did the ORM when leaving the parking lot and 5k later still no soot on MAP sensor or FCV. when the ORM is done it keeps the FCV from operating when the ignition is on but closes it for approximately 10 seconds at shutdown.

Tinman · **Joined:** Mon Apr 10, 2006 10:45 am **Posts:** 308

oldnavy wrote:

You would be hard pressed to find a modern diesel running an auto trans that does not have a FCV, even most manual transmissions will have them. .

Hummm... didn't know that. Do those have he FCV just for those reasons or as part of the EGR? The Cummins in the Dodges have never had one but then again it is a tractor engine

longarm · **Posted:** Wed May 16, 2007 9:09 am

My CRD was just flatbedded to the stealership for the second time. A few months ago it was for the turbo dying. This time I have no idea. I had it parked in the garage for about 6 dsys while I was on vacation. It had about 1/3 of a tank of fuel. I got in it this morning to start it and it started just fine. I put it in gear after a couple minutes of warm up and it died. Then it refused to start again. I walked away then came back a few minutes later to try again. It cranks over just fine, it just won't start up. Sooo, I called roadside assistance and they flatbedded to the dealership again. I'm awating to see the problem. I am glad for everyone in here who has had no problems, but this is by far the most problematic vehicle I have ever owned.

nursecosmo · **Posted:** Thu May 17, 2007 11:01 am

Quote:

Hummm... didn't know that. Do those have he FCV just for those reasons or as part of the EGR? The Cummins in the Dodges have never had one but then again it is a tractor engine Very Happy

Quote:

Besides the (supposed) smooth shutdown function, the FCV also assists in the EGR system operation. It acts as a sort of throttle to adjust the fresh air ratio in relation to exhaust gas.

nursecosmo · **Posted:** Thu May 17, 2007 11:04 am

I sure wish that I could figure out how to use the quote feature on this forum. Maybe someone could instruct me.

msilbernagel · **Posted:** Thu May 17, 2007 12:44 pm

Top right-hand corner of anyone's post, a little square box with red letters that says [quote].

Seriously. However, it is rather small font.

Mark

nursecosmo wrote:

I sure wish that I could figure out how to use the quote feature on this forum. Maybe someone could instruct me.

erockskj · **Posted:** Fri Jun 08, 2007 12:28 pm

[quote="longarm"]My CRD was just flatbedded to the stealership for the second time. A few months ago it was for the turbo dying. This time I have no idea. I had it parked in the garage for about 6 dsys while I was on vacation. It had about 1/3 of a tank of fuel. I got in it this morning to start it and it started just fine. I put it in gear after a couple minutes of warm up and it died. Then it refused to start again. I walked away then came back a few minutes later to try again. It cranks over just fine, it just won't start up. Sooo, I called roadside assistance and they flatbedded to the dealership again. I'm awating to see the problem. I am glad for everyone in here who has had no problems, but this is by far the most problematic
vehicle I have ever owned.[/quote

Same here. First time flatbeddeded to SS.I had just recently installed cat filter-( primed it
no leaks, ran fine for about 100 miles, then began to lose power the die :evil:

poped hood primed again and limped home ( barely) now will not crank :cry:

Two days + at SS and all they can say is its fuel starved and don`t know why
I`ll post again when I find out something[/u]

skywarn · **Posted:** Fri Jun 08, 2007 2:18 pm

EROCKSKJ -

if your poor Jeep is in fact at the dealer... i think its a sad day... your going to have to loose the last line of your sig now....

your CRD just got Flashed.... :shock:

By law they have to do it... :cry:

erockskj · **Posted:** Fri Jun 08, 2007 3:15 pm

skywarn wrote:

EROCKSKJ -

if your poor Jeep is in fact at the dealer... i think its a sad day... your going to have to loose the last line of your sig now....

your CRD just got Flashed.... :shock:

By law they have to do it... :cry:

Quote:

Yeah my biggest fears :roll:

I had no prblems with my jeep till this.
When I get it back I`ll go back to ORM and put my chip back,
I`ll be pi$$ed if my torque is missing :evil:

They did ask me if I wanted to do the recall (f37) I said no, lets fix this problem first.
This is day three and it is not fixed, they are STUMPED

erockskj · **Posted:** Tue Jun 12, 2007 3:54 pm

Ok, just got a call from the SM, said they were on the phone to DC
and had replaced the filter head ( thinking I messed it up with the cat filter)
primed it and still no crank. Now their guess is it`s the crank sensor not teeling the fuel pump
to come on. They will be getting one thursday and try that.

Hope that works I miss my jeep

Something new - Starting problem

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