Question ????...is the EGR ( Exhaust gas recirculation) valve hooked up to the stock V-6 necessary ???...I've been told that some people block it out. Your input please. Thanks
i would not say the egr will increase gas mileage. but a proper system that is operating properly will reduce emissions. It is designed to only work at cruise and steady throttle operation. if it stays open you will get idle surge or engine dying at idle. stumbling when acceleration. all sorts of things that resemble a vacuum leak.
i would not say the egr will increase gas mileage. but a proper system that is operating properly will reduce emissions. It is designed to only work at cruise and steady throttle operation. if it stays open you will get idle surge or engine dying at idle. stumbling when acceleration. all sorts of things that resemble a vacuum leak.
A proper functioning system will improve efficiency of the engine. The MPG change as a result may not be entirely noticeable to most people though. Since it would be recirculating part of the spent exhaust mass at cruise, it would indeed have a small effect on MPG.
The ECM software works with the EGR system to reduce unburned hydrocarbons at highway speeds by adding exhaust gas to the intake manifold. The computer is programmed to take that into account when firing the injectors. If you remove the EGR hardware, your mileage will be worse. If you remove the EGR system and re-program the ECM, your mileage may be the same as a well-maintained stock engine. Because there is no clear advantage to removing the EGR system, and there could be added expense and more air pollution, most automotive pros recommend that you keep it.
EGR will help your economy, albeit slightly. During EGR operation, the fueling is a bit leaner, and the spark is advanced a bit. This is made possible due to the introduction of the recirculated exhaust gas, which is inert. The inert gas helps to cool the whole burn cycle. (Which is actually what reduces emissions.) EGR does NOT make it run lean, by itself, as some people state. The "lean-ness" is programmed in. That's why a disabled EGR, with no programming changes made to accommodate it, can damage the engine. Not guaranteed in every case, but quite possible. If it's disabled, and your engine pings, you are causing damage.
I think there is really only one downside to having an egr and that is the inside of your intake will get coated black from the exhaust gases. Other than that it is a positive in every other way
If you want to do away with the egr you have to get the prom reflashed if that can be done. Did it to my tuned port injection using a 92 ecu that was the 730. So If The FIero Ecu IS PROGRAMMABLE Then yes.
The ECM software works with the EGR system to reduce unburned hydrocarbons at highway speeds by adding exhaust gas to the intake manifold. The computer is programmed to take that into account when firing the injectors. If you remove the EGR hardware, your mileage will be worse. If you remove the EGR system and re-program the ECM, your mileage may be the same as a well-maintained stock engine. Because there is no clear advantage to removing the EGR system, and there could be added expense and more air pollution, most automotive pros recommend that you keep it.
The only benefit I see is that you won't have to spend $200 dollars to replace the egr and egr solenoid down the road but you have the expense of reflashing the prom.
I think there is really only one downside to having an egr and that is the inside of your intake will get coated black from the exhaust gases. Other than that it is a positive in every other way
Then your EGR system is faulty, or you are running too rich for some reason.
If you want to do away with the egr you have to get the prom reflashed if that can be done. Did it to my tuned port injection using a 92 ecu that was the 730. So If The FIero Ecu IS PROGRAMMABLE Then yes.
The Fiero ECM is reprogrammable. Actually, the programming is done to a removable PROM chip. Similar to the 7730, except the chips are 2732s. They require a UV eraser. They also come in a simple black plastic carrier, instead of the blue MEMCAL package.
The Fiero ECM is reprogrammable. Actually, the programming is done to a removable PROM chip. Similar to the 7730, except the chips are 2732s. They require a UV eraser. They also come in a simple black plastic carrier, instead of the blue MEMCAL package.
Yeah I couldn't find the correct v8 ecu so I got the v6 ecu and purchased the reflashed prom.
Over the years I have tried removing, bypassing, etc EGR systems on my Fiero's to see what the change would do. In short, unless the car is strictly for racing, a well maintained EGR system is the way to go! You will be happier with the drivability, MPG's, smell, etc. and you will be legal. Too many people blame problems on the EGR system that are actually other problems.
------------------ "Because in a split second, It's gone" Ayrton Senna
The main purpose of the EGR system is to reduce NOx emissions during part-throttle cruising. NOx emissions are one of the main ingredients in acid rain, so it's nothing to scoff at.
That said, the Fiero V6 EGR system is pretty kludgey, IMO. It uses a vacuum switch connected to ported vacuum (only gets vacuum at part throttle), to signal the ECM when the engine is at part throttle. The ECM uses that signal, plus other engine operating parameters, to decide if it should activate the vacuum solenoid. If it does, then the solenoid sends manifold vacuum to the EGR valve to activate it. And finally, the EGR valve sends some exhaust gas back into the intake plenum.
Yeah, the EGR solenoid is expensive. But the alternatives are:
1) Pollute the air with stuff that causes acid rain 2) Rig up a custom EGR setup
[This message has been edited by Blacktree (edited 09-23-2015).]
But don't get me wrong. I'm not trying to trash the 7730 ECM swap. I'd actually suggest that (plus the digital EGR) to replace the antiquated Fiero electronics.
As radar said the exhaust gas is inert, thus doesn't burn, so the exhaust gasses displace some of the room in the combustion chamber, thus require less gas, that is how the EGR works
Sounds like this is part of the explanation for some of the pinging I hear on the 3.4 engine swap. The previous owner did an EGR delete but also claims to have done a ROM upgrade. I am tempted to reinstall the EGR when I get time. I just hope the parts will fit. I did the replace on Kevin's stock 2.8 when it was leaking and the car was driving like new until the accident.
