EGR system - ZR-1 Net Registry Forums

secondchance · 04-24-2009

I believe EGR system was added after 93 model year LT5.
I always thought EGR came into play after cold start and its purpose was to aid in faster warm up in order to control emissions.

A few minutes I was talking to a local mechanic regarding light detonation at light throttle and he was saying that it may be due to clogged EGR valve.

Does EGR come into play after motor has been fully warmed up?

Your thoughts?

04-24-2009

Quote:

Originally Posted by secondchance

I believe EGR system was added after 93 model year LT5.
I always thought EGR came into play after cold start and its purpose was to aid in faster warm up in order to control emissions.

A few minutes I was talking to a local mechanic regarding light detonation at light throttle and he was saying that it may be due to clogged EGR valve.

Does EGR come into play after motor has been fully warmed up?

Your thoughts?

EGR was added in 93. It was planned for the earlier models but was not included, hence the boss on the side of the plenum.

What you are thinking of is the air injection system which helps push air in to the exhaust system to help the cats get up to temp quicker.

EGR only functions while at a cruise.

Jagdpanzer · 04-24-2009

Hey Jeff,
Do you know under what specific conditions the EGR valve opens and closes?
Does it operate either fully open or fully closed or is it proportional?

secondchance · 04-24-2009

Quote:

Originally Posted by Jagdpanzer

Hey Jeff,
Do you know under what specific conditions the EGR valve opens and closes?
Does it operate either fully open or fully closed or is it proportional?

That was my next question.

Aurora40 · 04-24-2009

I suspect he is referring to a malfunctioning EGR valve. In which case the operating parameters for it are not that relevant. If the valve won't close properly, you can have driveability issues. I don't know that detonation is one of those issues, though.

I don't know how prone the LT5 system is to that, nor how easy it is to check or clean the valve, etc, since my car does not have EGR.

Do you get detonation at light throttle?

FYI, as Jeff mentioned, the AIR pump warms the cats up faster. EGR I believe is to prevent excessive NOx emissions by cooling down the combustion chamber

secondchance · 04-24-2009

I am getting mild ping when fully warmed up, 2000 to 3000 rpm, moderate acceleration.
One suggestion was to drive the hell out of the car (to 7000).

I was thinking of running BG K44. Should besafe, right?

carter200 · 04-24-2009

Quit running that cheap 87 and step up to some 93

secondchance · 04-24-2009

Quote:

Originally Posted by carter200

Quit running that cheap 87 and step up to some 93

Ha, ha. Very funny!
I use to run Sunoco 94 'till they droped it about 5 years ago. Since then, either Exxon or BP (Amoco) 93 - Mostly Exxon.

Kevin · 04-24-2009

are you talking about tip in knock or does this happen with no throttle changes?

secondchance · 04-24-2009

At tip-in. Starts right around 2000 to 2200, sometimes continuing to around 2600 to 2800.
This only occurs with slight acceleration and goes away if I push the throttle more aggressively.

04-24-2009	#1
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,723	EGR system I believe EGR system was added after 93 model year LT5. I always thought EGR came into play after cold start and its purpose was to aid in faster warm up in order to control emissions. A few minutes I was talking to a local mechanic regarding light detonation at light throttle and he was saying that it may be due to clogged EGR valve. Does EGR come into play after motor has been fully warmed up? Your thoughts?

04-24-2009	#3
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,661	Re: EGR system Hey Jeff, Do you know under what specific conditions the EGR valve opens and closes? Does it operate either fully open or fully closed or is it proportional?

04-24-2009	#5
Aurora40 Join Date: May 2005 Location: Leesburg, VA Posts: 2,713	Re: EGR system I suspect he is referring to a malfunctioning EGR valve. In which case the operating parameters for it are not that relevant. If the valve won't close properly, you can have driveability issues. I don't know that detonation is one of those issues, though. I don't know how prone the LT5 system is to that, nor how easy it is to check or clean the valve, etc, since my car does not have EGR. Do you get detonation at light throttle? FYI, as Jeff mentioned, the AIR pump warms the cats up faster. EGR I believe is to prevent excessive NOx emissions by cooling down the combustion chamber __________________ Bob Saveland Former owner of #2517 [IMG]http://a.random-image.net/aurora40/vette.jpg[/img] Last edited by Aurora40; 04-24-2009 at 02:42 PM.

04-24-2009	#6
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,723	Re: EGR system I am getting mild ping when fully warmed up, 2000 to 3000 rpm, moderate acceleration. One suggestion was to drive the hell out of the car (to 7000). I was thinking of running BG K44. Should besafe, right?

04-24-2009	#7
carter200 Join Date: Jun 2004 Location: Texas Posts: 2,431	Re: EGR system Quit running that cheap 87 and step up to some 93

04-24-2009	#9
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,632	Re: EGR system are you talking about tip in knock or does this happen with no throttle changes? __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

04-24-2009	#10
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,723	Re: EGR system At tip-in. Starts right around 2000 to 2200, sometimes continuing to around 2600 to 2800. This only occurs with slight acceleration and goes away if I push the throttle more aggressively.