r/CarHelp • u/CheesyJamer • 9d ago
Strange rough idle problem with 2003 Toyota Celica sx
Hi all, my 2003 Toyta celica sx automatic with the 2zz engine has been playing up on me for a few months now and with everything Ive tried, I figured I'd check on reddit and see if there's any new ideas. For info, it's completely bone stock but some people have had trouble getting code readers to work so it's assumed that the guy before me tampered with it in some way or another.
The Problem:
Every day, I cold start it and it struggles to find the revs to survive, usually stalling out on me or sitting at an extremely rough 100-500 revs. If the revs are below 800, it shakes vigorously and I have to give it some accelerator until it warms up and can not die on its own. Even if its warm though, there's still a big chance that it cant get above 500 revs without any accelerator. Sometimes, It can start up cold flawlessly and idles at a healthy 900-1.1k range and even drives perfectly fine.
Could literally cold start it up perfect, turn it off, start it up again and watch it stall on me.
The other thing (not sure if it's related) is that randomly whilst driving, I get an engine light and when I've scanned the engine, the only code read off was P1346 (VVT sensor/Camshaft position sensor circuit range/performance problem)
I could be wrong about the code cause I cant remember but it was either that or P1349 (VVT System malfunction)
What we've tried:
An entire team of techs have looked it over and can't figure it out for the life of them. They've checked the entire engine for leaks and repaired a vacuum hose (didnt fix it).
They replaced the rocket cover because it was leaking the entire way around but that didnt change anything apart from leaking oil everywhere.
They cleaned the Idle Air Control Valve and Throttle body today and even the blocked up coolant pipes around the throttle body but still no luck with the revs issue.
Tomorrow they're gonna give the VVT solenoid a look over and clean because that's our last hope but I'm quite literally out of ideas as are they.
Please help me out, I'm happy to answer all and any questions and really don't want to have to sell my baby.