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  #1  
Old January 10th, 2018, 13:01
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jrowell jrowell is offline
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When does the EGR activate?

Got this cool little REM device that tells me whats going on with my RENIX real time. While scanning through all the options I notice that my EGR doesn't go into on mode very often. When is the EGR supposed to activate?
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Old January 10th, 2018, 14:20
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Ecomike Ecomike is offline
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Re: When does the EGR activate?

During rapid deceleration, like brakes applied on the freeway, rapidly slowing down as I recall. Going from say 3000 rpm (in gear or not) to idle on the gas peddle.
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34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
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Old January 10th, 2018, 14:21
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Re: When does the EGR activate?

Quote:
Originally Posted by jrowell View Post
Got this cool little REM device that tells me whats going on with my RENIX real time. While scanning through all the options I notice that my EGR doesn't go into on mode very often. When is the EGR supposed to activate?
Which REM version do you have?
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Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
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Old January 10th, 2018, 14:53
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jrowell jrowell is offline
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When does the EGR activate?

Great little unit. Very happy with it.

Sent from my SM-G930V using Tapatalk
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Old January 12th, 2018, 13:18
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jrowell jrowell is offline
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Re: When does the EGR activate?

Quote:
Originally Posted by Ecomike View Post
During rapid deceleration, like brakes applied on the freeway, rapidly slowing down as I recall. Going from say 3000 rpm (in gear or not) to idle on the gas peddle.
If these are the only times it activates, how would the EGR affect a smog test?
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Old January 12th, 2018, 18:04
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Ecomike Ecomike is offline
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Re: When does the EGR activate?

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Originally Posted by jrowell View Post
If these are the only times it activates, how would the EGR affect a smog test?
If it works properly it reduces NOx emissions when it opens by keeping the engine from running too lean.

If it stays open when it should be closed it screws with, dilutes, the O2 concentration, making the ECU think the engine is running lean, and so it adds fuel when it should.

IIRC.

I'd have to sleep on it for a day to recall the rest of what I once knew about that answer.
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Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
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Old January 13th, 2018, 14:26
lawsoncl lawsoncl is offline
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Re: When does the EGR activate?

Quote:
Originally Posted by jrowell View Post
Got this cool little REM device that tells me whats going on with my RENIX real time. While scanning through all the options I notice that my EGR doesn't go into on mode very often. When is the EGR supposed to activate?
How does the REM determine when the Renix EGR is open if it's not controlled by the engine computer? The EGR valve is vacuum operated with a CTO switch that blocks the vacuum if the engine temp is below 100*F, and you may also have a thermal switch in the air cleaner housing to block the vacuum if the air temp is below 40*F.
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Old January 13th, 2018, 17:09
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Ecomike Ecomike is offline
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Re: When does the EGR activate?

The REM is a brand new, next generation, live data scanner for Renix ECUs that reads the ECU data stream and spies on it :-)

So when the Renix ECU commands the EGR to open, the REM scanner displays that command.

I am waiting for the final version to come out. It has about 10 versions and 20 open programming updates already. The guy making them must have made over 150 of them already.

And yes, the Renix does have a thermal switch but it does not get involved directly with the EGR. It operates a diverter intake air valve in the filter box to an air intake hose that pulls hot exhaust manifold air into the intake during the warm up period.

Quote:
Originally Posted by lawsoncl View Post
How does the REM determine when the Renix EGR is open if it's not controlled by the engine computer? The EGR valve is vacuum operated with a CTO switch that blocks the vacuum if the engine temp is below 100*F, and you may also have a thermal switch in the air cleaner housing to block the vacuum if the air temp is below 40*F.
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Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
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  #9  
Old January 14th, 2018, 08:29
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jrowell jrowell is offline
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Re: When does the EGR activate?

Quote:
Originally Posted by Ecomike View Post
The REM is a brand new, next generation, live data scanner for Renix ECUs that reads the ECU data stream and spies on it :-)

So when the Renix ECU commands the EGR to open, the REM scanner displays that command.

I am waiting for the final version to come out. It has about 10 versions and 20 open programming updates already. The guy making them must have made over 150 of them already.

And yes, the Renix does have a thermal switch but it does not get involved directly with the EGR. It operates a diverter intake air valve in the filter box to an air intake hose that pulls hot exhaust manifold air into the intake during the warm up period.
I'm glad you were able to answer that cause the only explanation I could come up with is magic!

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  #10  
Old January 14th, 2018, 11:53
lawsoncl lawsoncl is offline
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Re: When does the EGR activate?

Quote:
Originally Posted by lawsoncl View Post
How does the REM determine when the Renix EGR is open if it's not controlled by the engine computer? The EGR valve is vacuum operated with a CTO switch that blocks the vacuum if the engine temp is below 100*F, and you may also have a thermal switch in the air cleaner housing to block the vacuum if the air temp is below 40*F.
Okay, feeling dumb now. The electrical solenoid is right there next to the ballast resistor.
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Old January 14th, 2018, 14:47
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1990JEEPXJ 1990JEEPXJ is offline
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Re: When does the EGR activate?

Off topic, where does one get one of those little REM readers?
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  #12  
Old January 14th, 2018, 14:57
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Ecomike Ecomike is offline
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Re: When does the EGR activate?

He has a user account here, but I follow him on facebook. He also has a lot of Renix you tube videos he has been doing the last year. There is an REM post in the OEM forum from about 6 months ago also. Here is the URL from facebook, Just google nickintimefilms or use this link to get all the links to him. Very VERY bright young fellow.

https://www.google.com/search?ei=5t9....0.8eKQbzk370k
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Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
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