EGR Valve?

[johndeeregarner]

Hey guys, I was wondering if it was necessary to have my EGR valve hooked up? I was told that I would get better HP if it wasn't. Is that true?

Thanks

 

[Psychopete]

No, that's not true. The computer compensates for the EGR flow and expects it to be there when the EGR valve is open. Typically you'll end up with a rich condition, which is going to hurt performance more than help.

Pete

Edit:
If you really want to get rid of it, it is possible to swap in a later model computer with no EGR, but I heard the a/f calculation is not as aggressive since 86-87 Rangers had a knock sensor to bump the timing down if it sensed pre-ignition. I am not sure how true that is though.

 

[Wicked_Sludge]

you will not gain any power from unhooking or otherwise disabling the EGR. in fact, your more likely to loose power (it wont run rich, but it will loose time).

other results of disabling the EGR can include poor fuel economy and spark knock...along with a host of drivability problems.

 

[johndeeregarner]

Oh ok. That clears it up. Thanks guys.

 

[Psychopete]

you will not gain any power from unhooking or otherwise disabling the EGR. in fact, your more likely to loose power (it wont run rich, but it will loose time).

other results of disabling the EGR can include poor fuel economy and spark knock...along with a host of drivability problems.

I am confused a little on this, how can you have worse fuel economy without wasting fuel (running rich) somewhere? Please clarify..

Pete

 

[85_Ranger4x4]

I am confused a little on this, how can you have worse fuel economy without wasting fuel (running rich) somewhere? Please clarify..

Pete

It won't be as effecient.

 

[Wicked_Sludge]

without the EGR, you loose ignition timing. less timing means a less powerful/complete burn, hense lower power and lower economy.

 

[Psychopete]

without the EGR, you loose ignition timing. less timing means a less powerful/complete burn, hense lower power and lower economy.

I am just saying based off what I've heard. A friend of mine indicated his '93 EFI 5.0L in a '79 Fairmont runs a little rich with no EGR. But who's to say there isn't another factor. But on the other hand, he replaced every single sensor trying to diagnose a bad new IAC.

My mom's car ('97 Grand Prix 3.8L) also ran VERY rich when the EGR solenoid went. It smelled like rotten eggs and the car constantly wanted to die once warm.

I can recall reading this as well (possibly in several places), here is an example from AD that's directly related to the subject:

ANY sort of "failure" of the system and the relatively stupid management
decides that the situation is not good and runs the engine full rich.

I am open minded to this, I am not saying that's how it is and that's that. I never removed the EGR system on an '87 Ranger and monitored the air fuel ration. This is just the perspective that I am coming from based on what I've seen and what I've heard from other reputable sources (I do consider you a reputable source for info, I am just stuck in conflicting statements).

Pete

 

[Wicked_Sludge]

there is a LOT of misconceptions on EGR function floating around on the internet. one of which is that it effects the engines air fuel ratios. it does not. exhaust gases are INERT...meaning they dont contribute any oxygen or fuel to the mixture, all they do is take up space. itd be the same effect as putting cotton balls in your combustion chambers (no wait, those burn ). if your engines fuel management is looking for a 14:1 a/f ratio it will obtain a 14:1 a/f ratio wether the EGR is there or not (in the case of not, more air is entering the chambers, so more fuel is applied to compensate).

allan is correct, however. vehicles that monitor EGR function via an EGR valve position sensor or DPFE sensor can be confused if the sensor fails electrically in such a way that it isnt an open circuit. if the PCM is expecting (for example) a voltage ranging from 1.2-3 volts and it recieves 6 volts...odd things can happen.

 

[Psychopete]

there is a LOT of misconceptions on EGR function floating around on the internet. one of which is that it effects the engines air fuel ratios. it does not. exhaust gases are INERT...meaning they dont contribute any oxygen or fuel to the mixture, all they do is take up space. itd be the same effect as putting cotton balls in your combustion chambers (no wait, those burn ). if your engines fuel management is looking for a 14:1 a/f ratio it will obtain a 14:1 a/f ratio wether the EGR is there or not (in the case of not, more air is entering the chambers, so more fuel is applied to compensate).

allan is correct, however. vehicles that monitor EGR function via an EGR valve position sensor or DPFE sensor can be confused if the sensor fails electrically in such a way that it isnt an open circuit. if the PCM is expecting (for example) a voltage ranging from 1.2-3 volts and it recieves 6 volts...odd things can happen.

I am still confused. Is AD's post accurate that it will ultimately run rich, or will only the timing be effected? FWIW, I do understand that exhaust cannot be re-burnt...



Pete

 

[Wicked_Sludge]

it depends on the type of failure that occures. most of the time, no...the PCM will not enrich the mixture.

 

[Psychopete]

it depends on the type of failure that occures. most of the time, no...the PCM will not enrich the mixture.

Could it be agreed upon that the removal of the entire system would be considered a significant failure of the EGR system as far as the computer is concerned?

Pete

 

[Wicked_Sludge]

in the case of removing the system (unplugging and removing any electrical sensors), the system will see an open circuit on any EGR related components. in this case it will throw a CEL and ignore input (or lack thereof) from said sensor. the engine will continue to run normally and in closed loop.

 

[rangerpimpn84]

so lets say i remove my egr valve in my 2.3 whats the result nothing besides thrown a code then right

 

[Wicked_Sludge]

you will not gain any power from unhooking or otherwise disabling the EGR. in fact, your more likely to loose power (it wont run rich, but it will loose time).

other results of disabling the EGR can include poor fuel economy and spark knock...along with a host of drivability problems.