2G WTF! Misfire Cyl 3!

[InfiniteGSX]

This is starting to piss me off! The car was running fine, I launched it just playing around in a empty parking lot testing out some things on the Tephra Rom. Tune is clean and gets good gas mileage so far. But after the launch, the car started spitting. I was low on gas when I did it and after went and filled up. Now its soo bad it mis fires even on normal driving, can hardly get maybe 2psi before the car breaks up hard.

I replaced the spark plugs and coil pack. Same Problem. I pulled all my intercooler pipes, cleaned them and the couplers and re sealed them. I recently just pulled my IAC/FIAV and replaced it with a blockoff plate because my IAC was completely bad. And I read up that it could back up into the ECU and damage it. That is NOT ok by any means in my book. So I'll enjoy shitty cold starts and bad idle until I can get a new IAC. But even with the blockoff plate nothing was wrong till after that launch.

I don't know what to do. I'm going to check Timing to make sure its still TDC and didn't jump. I've already taken a semi long drive with it out of town and back and besides the no power because no boost, the car ran great. Got good gas mileage so far around 250 to the tank. But I'm tired of it already. Tired of the embarassment of attempting to get on it a little and hearing it just PLAAAHHHTTTHHH (yes that was a sound ).

Someone help, Throw me some idea's!

1997 Eclipse GSX
6bolt Block
2g Head
2g CAS
1g tb
2g intake
Evo8 ECU
Tephra V7
Evo 560cc injectors
Innovative Digital WB
HRC 20g Turbo
100% 3" turbo back
VSRF Short Route FMIC

Uhm...... I believe thats all.

 

[jcarmichael]

could be the ignition pack if you have already tried wires and plugs. since our cars our setup with 1 and 4 and 2 and 3 firing at the same time I would switch them out and see what it does. if it didn't run good any other time I would say possibly a clogged injector but I couldn't see any of those things going bad from a launch.

 

[96' Eclipse GS]

Well, to start you can do a few more tests. Starting if you are getting power to the fuel injector(Noid test), followed by that 1st and 4th runs together. Is there any problems there with misfire on 1? I would start with that and go from there. Maybe if you have a way to link, look at the fuel side of what is going on during the misfire...

 

[afterburn]

Both are right since 1 and 4 and 2 and 3 fire at the same time switching the wires may help, Also if you have a compression tester. Check the compression of each cylinder and post there maybe a problem with the valves.

 

[icekilla126]

What does the plug in the affected cylinder look like.

 

[InfiniteGSX]

could be the ignition pack if you have already tried wires and plugs. since our cars our setup with 1 and 4 and 2 and 3 firing at the same time I would switch them out and see what it does. if it didn't run good any other time I would say possibly a clogged injector but I couldn't see any of those things going bad from a launch.

Injectors are new. Car was running fine until a launch. And I already replaced the coil pack. Car still runs and drives fine, just no boost without misfire.

Well, to start you can do a few more tests. Starting if you are getting power to the fuel injector(Noid test), followed by that 1st and 4th runs together. Is there any problems there with misfire on 1? I would start with that and go from there. Maybe if you have a way to link, look at the fuel side of what is going on during the misfire...

It was cylinder 3 on new injectors. Haven't tried the stock injectors yet because they were actually old and sticky. So doubtful they will help if the new injectors aren't.

Both are right since 1 and 4 and 2 and 3 fire at the same time switching the wires may help, Also if you have a compression tester. Check the compression of each cylinder and post there maybe a problem with the valves.

Compression is the exact same it was before the misfire.

What does the plug in the affected cylinder look like.

All 4 plugs looked the same, and didn't show any real bad signs. Just normal wear for the past few months. However I installed brand new plugs and it still does it.

My tuner keeps saying I'm just running rich when I'm boosting, but I'm not running any real different from before the problem. Why would it be normal and then too rich all of a sudden, nothing changed on the rom. Plus the WB doesn't show it being really rich, just normal rich under load.

 

[jcarmichael]

Better rich then lean, couldn't see running rich causing it not to boost. If you have the time I would swap the old injectors in and give it a try. The new ones shouldn't be messing up but never hurts ruling them out either.

 

[SPYDERGSTTUNER]

Ok i gotta get in on this one, sorry infinitegsx im not trying to hijack your thread but im having the same issue, cylinder 3 misfire. Mine started to sputter and misfire after i extended my coil wire to relocate the coil, i checked to make sure i wired it correctly,changed plugs,wires,coil,and boost leak test but still same results.

 

[96' Eclipse GS]

Back to my question, Did you ever do a Noid Light Test? Like stated above switch out injectors and see what happens...

 

[tarheels23]

check the throttle position sensor. mine was too high and my car would run like crap and sputter under throttle

 

[InfiniteGSX]

Ok i gotta get in on this one, sorry infinitegsx im not trying to hijack your thread but im having the same issue, cylinder 3 misfire. Mine started to sputter and misfire after i extended my coil wire to relocate the coil, i checked to make sure i wired it correctly,changed plugs,wires,coil,and boost leak test but still same results.

Wait, so you did what to get the problem? And your saying when you went back to how it was before, the problem stuck? Just wondering....

Back to my question, Did you ever do a Noid Light Test? Like stated above switch out injectors and see what happens...

Noid light test?

check the throttle position sensor. mine was too high and my car would run like crap and sputter under throttle

TPS is apparently set right from what log says. Haven't set it exact with an ohm meter.

but like I said, the problem started right after a successful launch. I thought at first maybe I jerked the fuel pump loose... and its not holding enough pressure to flow at the high volume rpm's but I remember the fuel pump being jerked loose before and you could hear the fuel spraying inside the tank. Cannot hear it now. So was thinking of re sealing it just in case.

 

[96' Eclipse GS]

So, you have a question on what it is or have not done one yet on the car? (Noid Test)

 

[icekilla126]

Have you done a boost leak test.

Also Just thought of somthing else. Go over all your connecters. Make sure none of them came loose from the launch.

 

[InfiniteGSX]

dont know what a noid test is, unless it has another name.

Did a boost leak test AFTER I pulled all my charge pipes to clean them all up. That was my first thought. But never thought a misfire would come from a boost leak. I ended up ditching my IAC and FIAV just to make sure there were no boost leaks.

I did go over all the connections I could. Nothing seems to be having issues.

Got a video of it...
Misfire - YouTube

All of that 4000rpm+ stuff, the car is hardly accelerating. I have to always accelerate at like 5% throttle and don't go into heavy load or else it trips out.

 

[tarheels23]

mine kind of did that with the tps except when I hit the gas it wouldn't go anywhere and just sounded like a motorcycle revving out. How about your mass air flow sensor? do you know anyone you could borrow one off of? and try that

 

[96' Eclipse GS]

Here is a few helpful sites to get you started, if you still haven't even changed your injectors to see if the problem moves over or you have a wiring problem??? Start with this before you go replacing other things and spending money...unless you have done what has been said above on this post..

Noid Light » Noid Lights ? How to Test Your Fuel Injectors

Fuel Injector Noid Light Testing - YouTube

 

[InfiniteGSX]

I can't just change out my injectors yet. I'm having issues with my car and the Open Port so I cannot change that over yet. Two problems I've been working on. The misfire and the OP.

don't have anyone to try a MAF from. There are hardly any local 2g's. Its a rare occasion to see them.

I'll try that lil test thingy.

Ok, that lil test thing fails completely. All 4 Injectors stay lit. I tested both wires for ground and voltage with the car running and no flash or no light. Just lit all the time on both wires with injectors plugged up. Removed the Injectors and one side has voltage, the other side doesn't . Still no flashing. My car is not running extremely rich. Plus I don't think this test will help. Since I can't test it when its misfireing. It doesn't misfire at idle. It misfires at 4k+

 

[Mitsubishiown]

Hope you get it figured out soon man! I mean there is only so much it could possibly be! Seems you have eliminated a lot of it!

 

[InfiniteGSX]

Yeah so you can see my frustration. Hopefully tomorrow I'm gonna meet up with a fellow DSM'r who's very respectable. He should have all the parts needed to diagnose everything. Like a spare set of 560's. I hope he'll help me.

I know its getting worse. Now the problem is at low RPM's also. Or situations where your at low'ish rpm with it in a low gear... It jerks around until it gets up to around 3000rpm-3500ish.

 

[WES_393]

If your WB is correct your bouncing between 12-13 AFR at WOT. If your running pump gas that's way too lean. Are you using Link to tune?

 

[InfiniteGSX]

Oh no. WOT is around 10-11.5. Cruise is around 13-15 But usually sticks right in the center at 14.7ish. My tune is pretty nice. Unless the Evo8 ECU found a way to tune itself and change everything. Because it was running great. I didn't change shit. I launched the car on my way to pickup my brother, picked him up and tried getting on it a little to show him since he's never been in a car like this, and it spit.

Actually. I did just notice on the video, during the 3rd Gear WOT Pull... It was like 13.5... WTF? I almost wanna go try it again to see.


Alright just did a couple pulls in the same spot from the video right by my house. Car wouldn't go past 40mph at WOT. First pull it stuck to 13.5. All after it was around 10-11. While in a "pull" car wont go past 40mph, if I let off on it to get out of boost load, car will accelerate.

So I think its safe to assume the problem is getting worse.

 

[WES_393]

Ah gotcha, maybe the video was just making it look like 12's to me.

Have you checked the coils? Sorry if I missed that part of the thread, but if the plugs and wires are good I'd start looking at the coil.

 

[InfiniteGSX]

Double posts aren't supposed to happen! WTF....

Anyway, hell no @ using link. I am on a Evo8 ECU using ECUFlash.

 

[InfiniteGSX]

I don't have any other wires to try. I replaced the plugs. I installed a different coil pack. And I even tried a different PTU. In the past I was having coil pack issues where they would burn out within a day of use. I figured it was the PTU so I replaced the PTU and put another coil pack (I went through a couple) on the car and its been running since. But just today I put a different coil pack and PTU on and it still spits.

I am kinda thinking my ECU is bad. I read up that the IAC if bad can practically fry the ECU. Well my IAC was toast, all 4 coils in the IAC tested bad. So I pulled it instantly and replaced it with a blockoff plate till I can get a new one. But maybe I was too late.

So guess its time to give up on this car. I can't continue this shit. I can't afford another ECU. If its not too cold outside I'm gonna put the stock injectors and stock ECU back in.

 

[InfiniteGSX]

I replaced the 2g CAS and Crank Sensor with a 1g CAS. Just did timing. Still same exact misfire. So now that I've gone through everything.... what is next? Should I start stacking logs to burn this car to the ground? How can a simple launch just cause such a problem without any visible source? I would have expected it would have been something like spark plugs or maybe again a bad coil pack or something but no.