Resolved 1G EGR delete

[Joseph90talon]

I got a 1990 Eagle Talon and I thinking about cleaning up the engine bay a little. I want to delete the EGR valve and the vacuum lines that go to the emission equipment. I live in Michigan and it gets pretty cold at times during winter. Am I gonna have a problem with cold starts? What's the pros and cons of doing this?

 

[steve]

If the EGR system is working correctly it doesn't engage until after the car is up to operating temp. That's what the thermovalve in the thermostat housing does.

It's the FIAV and ISC in the Throttle Body that come into play for cold starts and fast idle warm up.

 

[Joseph90talon]

Ok while deleting these vacuum lines two go to Thermovalve. That's gonna affect my idle on cold starts then?

 

[steve]

Assuming you block off the EGR valve and plug the removed thermovalve hoses at the Throttle Body there should be no impact on idle on cold starts.

See if you can get a copy of the 1G Technical Information Manual, it discusses how the EGR system works as well as many of the other systems.

 

[enriquez2000]

The only thing that the EGR does is lower NOX on emissions. If you have to pass a test it may cause you issues and most definitely will on visual. Other than that you will never notice its gone.

 

[Joseph90talon]

Ok what's the purpose of the block off plate can't I just connect the two coolant lines of the throttle body togeather and cap of the two vacuum lines on the EGR valve off and call it a day?

 

[enriquez2000]

Ok what's the purpose of the block off plate can't I just connect the two coolant lines of the throttle body togeather and cap of the two vaccume lines on the egr valve off and call it a day?

Could... but i prefer a block off in case a line leaks

 

[Joseph90talon]

What lines could leak??

 

[steve]

Ok what's the purpose of the block off plate can't I just connect the two coolant lines of the throttle body togeather and cap of the two vaccume lines on the egr valve off and call it a day?

Could... but i prefer a block off in case a line leaks

Guys, what are you talking about? The water lines to the Throttle Body are for the Fast Idle Air Valve and have nothing to do with deleting the EGR.

If you mess with the water lines you going to break the FIAV and the car will have idle problems.

 

[Joseph90talon]

Sorry for the miscommunication Steve. I'm combining two separate topics, the EGR delete and the throttle body coolant bypass "mod".

I'm gonna do the EGR delete plate cause from my understanding who knows if the valve is open or closed when I cap the EGR valve off so for peace of mind I'm gonna block it completely off. As for the coolant bypass mod I'm gonna skip cause I tend to use this car as a daily driver.

 

[steve]

Thanks for explaining, I got lost for a second.

As you point out an EGR block off plate ensures that there isn't a vacuum/boost leak via the EGR passage, assuming it's not plugged full of carbon from the years of exhaust passing through it, and that you don't have EGR going on all the time from a stuck open EGR valve.

There are four emission control circuits in a DSM, EGR, PCV, Evaporation, and Catalytic. The EGR and Evap Purge are easy to remove. The PCV on a turbo car difficult to remove or maintain and the Catalytic is tied into the ECU's basic strategy of open/closed loop. Part of the factory tuning is designed to produce exhaust gasses that will work with the converter for secondary combustion to lower emissions.

The TB Butterfly, ISC, FIAV, and BISS work together to control the volume of intake air. The last three to modify the volume of bypass air at any given time. The FIAV is mainly for cold engine starting and warm up. When the coolant is cold the FIAV allows extra air to bypass the TB Butterfly. As the coolant temp rises the FIAV closes, at 50C it shouldn't be bypassing any air. The ISC primary function is to maintain the idle speed using feedback from the CAS. It also is used to emulate a dashpot to buffer the effect of closing the butterfly, and to provide cold startup air.

 

[Joseph90talon]

Thanks a ton for breaking it down Steve!