check engine / running rough

B

BlackMark8

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Okay, so i wont lie, i raced a WRX STI by the airport today, and i used a fresh bottle of nitrous. So it worked good. (Yes i won the race by a car length, with 3 people in the car) - Anyways, after that, the engine started running rough, the temp was ok - it felt like it was missing a spark or something, kinda shaking when i try to get up on it. And my check engine light was flashing, and kept flashing until i got home. Then after letting it cool off, i started it and it started smoking badly ! White smoke, and i noticed it leaking out my intake as well, after i shut her off. It will only smoke when i rev it up , still shaking kinda roughly. I checked the oil, its fine not mixing with my coolant.Anyone have any ideas? ? What is the general cause of making the check engine light FLASH on and off??

Oh and i changed my spark plugs about 6k miles ago
 
did you pull the plugs out and look at them, you may have melted a plug and have a dead cyliner or a few, i have seen nitrous totally glob the end of a spark plug up before, the smoke might be alot of fuel maybe. how big of a shot did you run through it?
 
Yes bone stock, No tune, no other mods. What causes the check engline light to flash on and off, anyone know? oh and she has 160k miles
 
well i cant say what is causing the light, but i can tell you this much, 30 bottle of 100 shot through a stock motor with 160k on it, sounds like you have much more to worry about now than just a blinking light. the rough running and smoke is obvious signs on internal damage.
 
Nah i think its my manifold intake leak. May have gotten worse. It doesnt tap or make any bad sounds, just missing a cylinder. And the smoke is the unburned fuel. I thought someone here would know what the flashing check engine light means. It flashes then stays solid for a little, then back to flashing
 
ok advanced auto told me the diag reported these things:

1 - idle air control (ofcourse)
2 - cylinder number 8 is not firing
3 - airflow ??? airflow injection ?? something like that the guy said" i never seen this one before"
4 - system is running too lean

First id like to know which one is number 8 (for a 97 lsc) so i can pull that plug and look at it. And second, anyone know what airflow injection this man speaks of ??

Also - I had a check engine light come on about 5 months ago and checked it and it said system running too lean.Any knowledge of how i can correct this? someone told me it was just clogged up cats. Any other ideas or questions?? Any info is GREATLY appreciated. Also i am planning to become a full member soon and also will soon be giving donations.

Thanks again in advance
 
Number 8 cylinder is farthest back on the drivers side.

"Airflow injection" is likely the air injection system for emissions.

Running lean is just what it says - not what I'd want to hear running nitrous. Could be a number of things, starting with O2 sensors.
 
Okay so any pointers on why number 8 isnt firing? I checked the plug and cleaned it, but thats all i did. Think the faulty O2 sensors can make it run crappy and make number 8 miss ?? idk - also, my coilpacks seem to fit on really loosely and i see someone has changed the two inner ones. Any suggestions ??
 
could the 02 sensors make it run rough and miss on number 8 ?? idk - and the air injection, could that make it miss number 8, and how? Any reason why number 8 isnt firing ?? I checked all the plugs on driver side and they seem ok, but my coilpacks fit on really loosely. and someone changed the inner two which seem to connect more firmly. Should i change the coilpack? whats the general price range on them? Any suggestions ?? Thanks
 
Most logical cause would be a bad coil or coil boot. The boots are quite cheap and available separately. That's where I would start.
 
take the coil off the number 8 plug and swap the coil with the cylinder in front of it and see if the missfire goes to the other cylinder, if it does, you need an ignition coil, around 35 bucks each at autozone.
 
ok i changed my coil pack and boot, and still... not firing on number 8 cylinder, i am going to change the plug next, what could be stopping number 8 from firing ?? can faulty O2 sensors do that?? what could ?? thanks
 
Well the other thing could be a clogged or malfunctioning injector... on Cyl #8... hence your lean condition also.

Man running 100 shot on an engine with 160k miles... you got balls of steel buddy.
 
ive been doing it for a LOONNG time now, and it always seemed to take it just fine, no noises, no pinging, no overheating, nothing ! And i hit the nos the last time and now its doing this, misfire cylinder 8 and now its blowing out a bunch of blue smoke. Like i said, no noises can be heard from the engine, it purrs like a kitten - just idling rough and you can hear is "sputter" when you get up on it - along with the huge cloud of blue smoke when i step on her a little
 
Blue smoke is burning oil... I would seriously suspect that you messed up some internals on cylinder #8... probably a piston ring or who knows...
 
ok i talked to my uncle and we did a few tests with compression, and its all there, compression is ok. the burning oil is coming from my exhaust because it may have a valve guide leak and if piston is not firing then it builds up ( i drove it on 7 cylinders apprx. 50 miles) and that would explain why it wasnt smoking untill awhile after it started missing. im not %100 about this though -

So i hooked up my coilpack to the spark plug and started her up and.... nothing. No spark - im getting a spark plug now to test it on a new/different one. If it does not spark after that what could cause the computer to not send a spark to that cylinder ?? its a new coilpack i just bought.


-and a reply to your post maxmk8, you may be right, i could have blown a ring, and i hope not and thanks for your input. but is it weird that i run nitrous all the time (just a shot here and there) and full runs on it at the track with full traction and never just popped. And when i just tap on it for a second to pass a car , after i get down to cruise speed it just starts missing. i know she has alot of miles but even on 7 cylinders it runs really good. Very powerfull still

thanks again to everyone for you help and support !
 
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This is from nitrous runs...

c_eTIEEw0q2I3E3H3kovtSLTqTI7F30LaVf7l6tzJFnJeH7WJbPRcbb_5NmWZpQ9ZEi9DMavGR2EtmAIt_j1-Q


Yeah, you've got compression, good. The plug could be bad, the coil, the boot, the signal wire, the injector, ... but bad O2s will not prevent number 8 from firing.
 
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