TL:DR Look at picture below and tell me WTF this thing is. Thanks.

Hi people!

I have been having this super annoying issue with my car where it jerks SO MUCH! Sometimes it doesn't happen for a few days, other times it'll happen for several days. Sometimes it'll happen only when the engine is cold, other times it'll happen when warm. I've replaced a few components during my diagnosing attempts and the car ran better overall each time I replaced something (come on! I have more miles than you after all!), but I still had to put up with the jerking! Keep in mind that my problem is resolved, I'm just giving you a back story!

I've done:
Full tune-up - was not overdue but didn't hurt to perform one
Fuel filter - that thing was nasty! The gas came out black
TPS - had amazing throttle response after replacing
Fuel pump - WHOA! Ran so smooth (of course when the issue wasn't occurring)

I suspected:
MAP - F**K THAT S**T! So damn expensive. Plus I flicked it hard enough and the engine didn't react (tried and true method of testing)
Engine mounts - they didn't look too bad
Clutch - passed all of my tests (plus, is about 4 years old)
Distributor - Uhhhhh, let's not go there...

So, I was checking for vacuum leaks today and noticed a sensor looking thing on the firewall, behind the TPS. I flicked it as hard as I can (I can bruise a human being with a single flick, sometimes make them bleed) and the engine stuttered and almost stalled out completely - told you my flick method works. I unplugged this device and the car has since ran soooo smooothly. OMG BRO, like its a new car! #firstworldproblems #WTFisthisSHIZ #INormallyDontHastagButIveBeenDrinking #nof*cksgivenSFWversion

So, what is this thing! I won't give excuses as to why I don't know what it is...I simply don't know what it is!

The engine bay is not of my car and is, in fact, not a Celica. However, the location of the unknown device is the same.

Thanks peeps!

If memory serves me correctly it's the A/C idle up valve.

No, I think it's an EGR solenoid now that I think about it. It'd explain the engine running better with it unplugged and performance being unpredictable with it plugged in. Though you'll end up with an EGR code after driving it twice.

Thanks Box! I think you're correct in saying it is the EGR solenoid. Advance Auto has the incorrect picture, but they both have two lines and a plug. And it does dump into the intake manifold. At only around $70, I think I'll be good

Thanks!

Give RockAuto a look. I want to say there's two solenoids, the one on the firewall and another down closer to the EGR tube. That's just going off memory though.

I think you were right the first time, iisnt it the air con idle up valve if it looks like that. I thought the EGR valve as attached to the engine....I have no idea why I think this, some distant memory from when I had a Corolla (before some daft tart wrote it off) but my memory isn't the most reliable source of information.

This post has been edited by Nial: Feb 10, 2015 - 1:38 AM

That's what I was thinking, but then I questioned myself on how it'd really mess with how it's running. I want to say there's a sticker on the firewall or hood that has everything labeled.

I'm missing all stickers...they fell off around 250k miles. Advance Auto gave me the wrong part, although the function seemed similar. I can't find anything on the idle up valve, plus it is in no way connected to the A/C system, but is connected directly to the EGR system. I'll just have to wait for one to pop up in the pull yard!

The idle up valve is somewhere in that area, I want to say it was between the intake manifold and some steel line toward the back of the motor. If I had one in person to look at I could tell you for sure. Then there was an EGR solenoid near the EGR valve/tube I believe. Hell if you have an OBDI car you can put a jim clip into the EGR temperature sensor harness and just remove the damn system.

This post has been edited by Box: Feb 13, 2015 - 12:39 AM

The AC idle up valve will have tubes going STRAIGHT to the intake manifold and throttle area. The EGR solenoid will have tubes going to the EGR valve or the transducer (disc thing).

Do you have a 7A or 5S?

Had pictures of the thing in my engine bay, but photo bucket is being stupid right now. Sorry

Ill try replying later when it works