Hey all,
I just registered to the board, but I've been a long time user .
Remember the high RPM misfire where the car would hit about 5K rpms and fall flat on it's face with the "machine gun" popping sound?
A lot of people thought it was turbo related, but it's acutally not...

I've been having some problems with this for the passed month.
Well recently, I accidentally fixed it.

It's not plugs, coilpack, sensors, or any of that.
Mysteriously, it was the EGR. I plugged the selenoid back in, drove it around for a good 30 minutes. Stopped and browsed walmart. and then drove another 30 minutes, just to make sure.
It hasn't been doing it for 3 weeks now.
I know some of you have been having this problem for a few years. From what I experienced from it, it REALLY sucks.

I've had my EGR unplugged for about a year and a half. I don't know what would possess it to start misfiring like that. All's I did was hook up the EGR and selenoid back up with the vacuum lines.

before that I tried sensors, coilpack, plugs, plug gaps, resetting the ECU, and I also checked for vacuum leaks. Nothing.

Well, I know a lot of you were getting VERY frustrated over this, so I just wanted to let you know about my findings. I hope it's as easy to get rid of for you now that I know what caused mine!

Take it easy.
good luck!]

-Josh

That does make sense because the egr helps cool the combustion.

-Roman

hows that it pumps hot gas back into the intake
?

MidKnight...can you see me now?

I've had my EGR blocked off for like 2 years now, and have never had that problem at high rpm, and at 15 psi..Usually that poping at high rpm is a misfire, usually because of being way too rich, or not enough spark to fully light the mixture. Also, EGR should be non functional at high rpm anyway. EGR mostly works at cruise, and light acceleration. But if that has worked for you, then it works..could be something else unrelated though.

13.5 @108 MPH-2.2 60ft(stupid FWD!)
S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential
fuel injection)
My webpage: http://eclipsed4evr.home.comcast.net
-1998 Mitsubishi Eclipse RS-T- "Toy"
-1992 Plymouth Laser Turbo AWD(SOLD)
-2000 Honda CR-V(daily)

yeah man, I know what you are saying. I've had mine blocked off for a year and a half, never once did it misfire like this. it was one of the first mods I did. Recently it started misfiring, and I came across that...

When gases heat up to over 2500 degrees, like in a combustion chamber, the nitrous and oxygen in the air chemically fuse together to form, you gussed it, nitrous oxide. We all know nitrous oxide with no added fuel is a no no. So you could either add more gas causing you to run rich which is bad for emissions, retard timing which hurts performance, or recirculate exhaust. Exhaust gas has already been burnt up, so recirculating it isn't going to burn it again. This cools down the intake charge and chemically cools and slows down the combustion process by a few hundred degrees. This is why I have never understood why people do away with their egr systems, especially with boosted applications. That's why it's pinging under full load because the gases are already compressed from the turbo, making them even hotter, and it's forming nitrous oxide. Everyone should have their egr on.

-Roman

Evo 8 - 12.3@113 circa 2009 (~330whp)
Now with BB Xona Rotor HTZ FP Red and ~450whp
2018 MSM Civic SI Ktuner TSP stage 1 w/ Honda hacked headunit.

not quite...
the combustion gases form nitrides of oxygen when they get too hot, and the reason the EGR cools it down is because the oxygen is already consumed in the exhaust gas, which cools down combustion (opposite of nitrous).

2005 Legacy GT Ltd, Garnet Red Pearl
speak softly and spool a big turbo

That's what I was trying to say. By already being burnt, I meant that it can't be burnt again because there is no oxygen. No oxygen= no fire.

edit: here you go

http://www.asashop.org/autoinc/nov97/gas.htm

-Roman

EGR is NOT functional at WOT. Its there for emmissions purposes, and nothing else. Engines have run just fine wihtout EGR systems for decades. The stock ECU may have lookup tables for the fuel/timing advance with the EGR operational, but when we are boosting(remember we have a check valve on the MAP sensor so it thinks its at WOT over 0 psi-hence NO EGR fuction), we are adding fuel without control from the stock ECU(FPR, MS, 8 injector, ect), so EGR doesnt really come into play in this case. EGR can be used to lower NOx emmissions, which also can help cool the combustion temperatures, and even let you run more timing advance, without having to run more fuel in the A/F mix. This is where better fuel economy, and lower emissions come into play, but mostly during cruise conditions. At WOT, the engine needs a richer mixture, and a more "constant" A/F mixture for power. It would be counter productive for power, to introduce EGR gasses at WOT since you have to run a richer than stoich(14.7:1) A/F mixture.

13.5 @108 MPH-2.2 60ft(stupid FWD!)
S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential
fuel injection)
My webpage: http://eclipsed4evr.home.comcast.net
-1998 Mitsubishi Eclipse RS-T- "Toy"
-1992 Plymouth Laser Turbo AWD(SOLD)
-2000 Honda CR-V(daily)

______________________________
If a sentence found online has 35% misspellings or greater and includes at least two racially charged expletives, chances are it is a YouTube comment.

'95 Eclipse TurboGS (garage deco)
'95 TSi AWD (restoring a survivor)
'97 Talon ESi-T (poor impulse control)
'99 Eclipse RS-T (daily beater)
'13 Evo X (mostly stock)
'17 Sienna (Middle Aged Dad Mobile)



Factory Service Manuals: http://nawdu.de/files/

Evo 8 - 12.3@113 circa 2009 (~330whp)
Now with BB Xona Rotor HTZ FP Red and ~450whp
2018 MSM Civic SI Ktuner TSP stage 1 w/ Honda hacked headunit.

Most engines don't like to idle too well when EGR gasses are introduced during a hot idle..So if your EGR is malfunctioning or sticking at idle, it will most def not idle well or even at all. It may run fine during engine warmup, since the added fuel enrichment may overtake just enough of the EGR flow to run ok. Then when warmup enrichment goes away when the motor comes up to temp, the A/F leans, and then it can run rough or die out.

13.5 @108 MPH-2.2 60ft(stupid FWD!)
S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential
fuel injection)
My webpage: http://eclipsed4evr.home.comcast.net
-1998 Mitsubishi Eclipse RS-T- "Toy"
-1992 Plymouth Laser Turbo AWD(SOLD)
-2000 Honda CR-V(daily)

Evo 8 - 12.3@113 circa 2009 (~330whp)
Now with BB Xona Rotor HTZ FP Red and ~450whp
2018 MSM Civic SI Ktuner TSP stage 1 w/ Honda hacked headunit.

couldn't hurt to try it out, right?