My car exhibits some weird behaviour when the engine is cold. If I hold the throttle pedal at one place whilst driving just after turn on, the car will kangaroo back and forth, sometimes quite violently. It's as if I am in a car with someone that doesn't know how to use the clutch properly. Once warmed up this doesn't happen.
I've also noticed weird idle when cold - mid temp. It kinda feels like it's misfiring on a cylinder, but not as jumpy, and it is quite infrequent. In my MK4 2.0 GTi, this was caused by the ignition coilpack, but it was a lot more aggressive.
What could be causing this behaviour? It is going in for a diagnostic tomorrow, but I am wondering if I can go into it with a bit of knowledge before hand.