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EP3 White smoke and misfire after IACV cleaning

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49
Hi guys!

I've just recently cleaned my IACV valve (be removing the Throttle body), with liberal use of intake cleaner.

I started the car up, there was plenty of white smoke at the back, I thought it would quickly burn off the excess cleaner still in the system.
A minute or so later the car started misfiring, I got the error code for random misfires in all cylinder, still with a lot of white smoke.

I ran the car for a couple of minutes, nothing changed (still misfiring and emitting a lot of white smoke).

The coolant seems to be at the same level as before, and the car had no problems before cleaning the IACV, I also made sure to connect all the wires correctly.

What could have gone wrong? Is it possible that the cleaner is burning off so slowly, or did some sensor get messed up because of it?

Thank you for the answers!
 
Ran the car a bit again, no change. Spark plugs are dirty (unburnt fuel), the white smoke also seems to be because of incomplete combustion. What could I have screwed up?
 
I have found no vacuum leaks, and everything seems to be plugged in correctly. I'm gonna check the MAP sensor tomorrow, that could produce such symptoms.
 
Yes, very likely, I sprayed some cleaner in the throttle body when it was assembled with all the sensors. Could it have killed it?
 
Well, if you unplug it and try to start the engine does it behave in the same way? You might be able to resurrect it by cleaning it with electronic parts cleaner (like NF, or contact-cleaner), but you should be careful with that too. While you have it off the car check the plug/wiring in case you broke a wire or pin during the process.

The current outcome sounds more serious than a failed MAP sensor to me though.
 
Thank you for the replies!

I tried cleaning the sensor with contact cleaner, no changes, unplugging it made it worse.

Checked all the spark plugs again, all of them had black discoloration (2 had a bit, the other 2 a lot of unburnt fuel on it, and their respective cylinders had some gunk as well looking through the spark plug holes).

My oil also seems to be diluted with some fuel (the level on the dipstick has risen by about 2-3 mm).

I'm gonna get new spark plugs on Monday, as well as oil and a filter, to change it after the issue has been fixed.

In the meantime, do you have any other advice, what else could I check?
 
Only P0300 (random misfires), P0301, P0302 and P0304 (specific cylinder misfires) codes are thrown, nothing else, even after resetting them.

Everything was fine with the car before, so I'm really hoping the plugs are the issue, cause I have no idea what else a bit of cleaner could have killed, especially without an error code.
 
I had an injector go faulty on my FD2 when pulling into JAE in 2015 I think it was. That only threw up a misfire in bank 1 code, so it could well be an injector or anything else on the spark, fuel or compression side of things.

Any chance it's had a rough crank whilst low on oil pressure and jumped a tooth on the timing chain? Might be enough to put all of the valves out if time but not enough for a sensor to register the cam position is wrong?
 
I don't think it could've jumped the chain, there was no rough cranking of the engine, it starts up okay and runs under no load for a few seconds, then, if I give it gas or wait longer it starts dying.
Injectors going bad I cannot rule out, but wouldn't it be unlikely that 2-3 went at the same time?

Fuel is definitely flowing, because all cylinders and plugs have signs of unburnt fuel, so the mystery is whether it gets too much fuel because of a sensor (or injector) fault or something is wrong with the spark. I can eliminate the latter tomorrow, I'll get the new plugs and check if they actually fire as well.
 
Got the new plugs, checked for spark and compression, everything seems to be fine in that regard.
The car started up like normal from cold, ran fine (and gave no CEL) under no load, but the unburnt fuel is still coming out the exhaust pipe.
So it is now clear that something with the mixture is wrong, but I cannot make it out what.

- TPS seems to be fine, revs like normal
- Unplugging the MAP made it worse, so that should not be the issue either
- O2 sensor got changed a month or so back, its basically brand new
- IACV is okay, the cold start revs are fine, and it starts dropping like usual as the engine warms
- No vacuum leaks
- No exhaust leaks
- No bent or broken connectors (or pins)
- Nothing out of the ordinary in the engine bay (no unusual sounds, no smoke, no oil or fuel spilling out of anywhere)

What else is able to alter the mixture? If any of the injectors are leaking, how would I be able to tell, should I take them out individually and inspect?

Thanks guys, I really appreciate your answers!
 
I'm pretty sure there are two different types of cleaner, one that is safe with o rings and evaporates and the other will eat o rings and doesn't evaporate. Could it be that you used the latter and the o rings have disintegrated causing over fueling?
 
I used specific intake cleaner, which is not supposed to damage anything if it gets into the intake manifold, but I won't trust these either after this case :D
I was not completely convinced that the MAP is not faulty, since that was the most likely thing I could have killed while cleaning, got a new one, but it made no difference.

So now it is pretty clear that something is not right with the injectors, but there is no fuel around them. Sorry for being a noobie here, never removed injectors before, can O-ring failure cause my symptoms without any external leakage? If so, what should I be looking for when removing them?
 
Injector O-rings seemed fine, replaced them anyway, but nothing has changed.
I tested the injectors, and none of them were leaking after pressurizing the fuel system (I took them out, cycled the ignition a couple of times, but no fuel dripped out).

If the injector closed when the engine shut off, there is no way it would be leaking while on, right?
 
Do you have a more advanced OBD II reader that can show O2 readings etc.? Is it possible the new O2 sensor is bad or a poor connection? If you unplug it does it change anything? Was it a true OEM part of something you found at a reduced price?
 
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