Quote Originally Posted by scorpion255 View Post
my suspicion right now could be the lpg kit which is connected to the radiator as well.
It is called the evaporiser, it has a bypass water hose going to the radiator and it has nothing to do with overheating issue. Hot water from radiator just passes to the evaporator and return back.

If you have overheating problem on gasoline mode likewise, then there are other problems aside from your LPG kit.

If you are having overheating problem on LPG alone, then your evaporizer was set very lean and that can also lead to jerking.

There's also a chance that your LPG injectors are clogs and may need cleaning.