LOST JEEPS
http://www.lostjeeps.com/forum/phpBB3/

Flow Control Valve stoped working, does that cut down on EGR
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=32971		 Page 1 of 1
Author:  Joe Romas [ Mon Jun 02, 2008 3:19 pm ]
Post subject:  Flow Control Valve stoped working, does that cut down on EGR
A week ago at 15k miles the gears on my flow control valve stripped and started making a loud racket. They have since gotten almost silent. I removed the hose and found the butterfly is free and spring loaded to the open position and I do't have a cel. Now since he FCV is not closing does that cut down on the egr gas going into the engine? If so this is something I might want to leave broken :lol: I really thought I would get a cel but have not yet.

Joe
Author:  Sir Sam [ Mon Jun 02, 2008 3:28 pm ]
Post subject:  Re: Flow Control Valve stoped working, does that cut down on
Joe Romas wrote:
A week ago at 15k miles the gears on my flow control valve stripped and started making a loud racket. They have since gotten almost silent. I removed the hose and found the butterfly is free and spring loaded to the open position and I do't have a cel. Now since he FCV is not closing does that cut down on the egr gas going into the engine? If so this is something I might want to leave broken :lol: I really thought I would get a cel but have not yet.

Joe


it wont make a difference in the EGR, just leave, it(unless you want the dealer to fix it) now that it's finsihed stripping out it will just stay in the open position and never cause a CEL.

the only difference you will notice is a slight shudder at shutdown, the last fire will rock the vehicle a little more.
Author:  UFO [ Mon Jun 02, 2008 4:07 pm ]
Post subject: 
I'm surprised you don't get a CEL, as without the valve operating, the EGR system may not be able to generate enough lower pressure to suck in exhaust gas over the boosted intake. In other words, the system shouldn't see a decrease in the MAF with an increase in EGR/FCV activation. That will set off a CEL with a bad SEGR, as shown by the 1.2 version with the defective PCB.
Author:  Joe Romas [ Mon Jun 02, 2008 4:37 pm ]
Post subject: 
UFO wrote:
I'm surprised you don't get a CEL, as without the valve operating, the EGR system may not be able to generate enough lower pressure to suck in exhaust gas over the boosted intake. In other words, the system shouldn't see a decrease in the MAF with an increase in EGR/FCV activation. That will set off a CEL


Those are my thoughts. I do notice the shutter on shutdown, no big deal thgere :lol:
Author:  Sir Sam [ Mon Jun 02, 2008 5:28 pm ]
Post subject: 
Joe Romas wrote:
UFO wrote:
I'm surprised you don't get a CEL, as without the valve operating, the EGR system may not be able to generate enough lower pressure to suck in exhaust gas over the boosted intake. In other words, the system shouldn't see a decrease in the MAF with an increase in EGR/FCV activation. That will set off a CEL


Those are my thoughts. I do notice the shutter on shutdown, no big deal thgere :lol:


Almost 25k miles on a bad FCV and no CEL yet.

the FCV is like the appendix of the CRD, heck the earlier versions dont even have it.

Also, I think a failed FCV can only net you better MPG since there is no longer a big restrictor plate up there.
Author:  MACKJ [ Mon Jun 02, 2008 8:23 pm ]
Post subject: 
UFO wrote:
I'm surprised you don't get a CEL, as without the valve operating, the EGR system may not be able to generate enough lower pressure to suck in exhaust gas over the boosted intake. In other words, the system shouldn't see a decrease in the MAF with an increase in EGR/FCV activation. That will set off a CEL with a bad SEGR, as shown by the 1.2 version with the defective PCB.

Nope. Had no CEL for 9 months now with the butterfly removed from the FCV.
Author:  Uffe [ Tue Jun 03, 2008 4:15 am ]
Post subject: 
UFO wrote:
I'm surprised you don't get a CEL, as without the valve operating, the EGR system may not be able to generate enough lower pressure to suck in exhaust gas over the boosted intake. In other words, the system shouldn't see a decrease in the MAF with an increase in EGR/FCV activation. That will set off a CEL with a bad SEGR, as shown by the 1.2 version with the defective PCB.


The pressure of the exhaust gasses must be higher than the intake pressure, otherwise the turbo will not spin.
Author:  UFO [ Tue Jun 03, 2008 10:17 am ]
Post subject: 
Uffe wrote:
UFO wrote:
I'm surprised you don't get a CEL, as without the valve operating, the EGR system may not be able to generate enough lower pressure to suck in exhaust gas over the boosted intake. In other words, the system shouldn't see a decrease in the MAF with an increase in EGR/FCV activation. That will set off a CEL with a bad SEGR, as shown by the 1.2 version with the defective PCB.


The pressure of the exhaust gasses must be higher than the intake pressure, otherwise the turbo will not spin.
That's not entirely true. There is mechanical advantage, one way or the other, depending on the aspect ratio of the scrolls. But the variable nature of the CRD turbo will probably allow it to generate enough back pressure to overcome the intake pressure and flow exhaust into it without the FCV. The FCV may enable it to work more "efficiently", but I suspect EGR must still operate with a defective FCV.
Author:  MACKJ [ Tue Jun 03, 2008 10:58 pm ]
Post subject: 
UFO wrote:
... but I suspect EGR must still operate with a defective FCV.

If you mean you need EGR...Nope again. I have the EGR blocked and the FCV inoperative with the butterfly removed...runs just like the old rattlers. The FCV closes slightly to allow the venturi effect to happen and pull the exhaust gases into the intake elbow...IMHO.
Author:  UFO [ Wed Jun 04, 2008 1:50 am ]
Post subject: 
MACKJ wrote:
UFO wrote:
... but I suspect EGR must still operate with a defective FCV.

If you mean you need EGR...Nope again. I have the EGR blocked and the FCV inoperative with the butterfly removed...runs just like the old rattlers. The FCV closes slightly to allow the venturi effect to happen and pull the exhaust gases into the intake elbow...IMHO.
No, all I meant is the EGR will probably still function with just a defective FCV, just not as designed.
Author:  MACKJ [ Wed Jun 04, 2008 3:22 am ]
Post subject: 
UFO wrote:
MACKJ wrote:
UFO wrote:
... but I suspect EGR must still operate with a defective FCV.

If you mean you need EGR...Nope again. I have the EGR blocked and the FCV inoperative with the butterfly removed...runs just like the old rattlers. The FCV closes slightly to allow the venturi effect to happen and pull the exhaust gases into the intake elbow...IMHO.
No, all I meant is the EGR will probably still function with just a defective FCV, just not as designed.

Yes, agree on that. The FCV creates the pressure drop.
Author:  Joe Romas [ Wed Jun 04, 2008 7:06 am ]
Post subject: 
MACKJ wrote:
UFO wrote:
MACKJ wrote:
UFO wrote:
... but I suspect EGR must still operate with a defective FCV.

If you mean you need EGR...Nope again. I have the EGR blocked and the FCV inoperative with the butterfly removed...runs just like the old rattlers. The FCV closes slightly to allow the venturi effect to happen and pull the exhaust gases into the intake elbow...IMHO.
No, all I meant is the EGR will probably still function with just a defective FCV, just not as designed.

Yes, agree on that. The FCV creates the pressure drop.


So it would seem I'm getting reduced egr gas flow and that is good :lol: AND there's a non invasive way to avoid intake clogging :wink:
Page 1 of 1 All times are UTC - 5 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/