740 b230k dies at idle

Hey guys,

Just bought cheap 1985 749 with auto gearbox and b230k with pierburg carb in it. Car has LPG system in it, so its bifuel double eco car: eco-nomy and eco-logy
The problem is that car was sitting in a shed for few years, so it wont start or drive on petrol - no fuel. Does it have in tank pump or only small one driven by oil pump shaft ?

Well, good news are, that it starts and drives on LPG, so hooray
Bad news - as soon as you let your foot off gas pedal it dies. I tried googling, but couldnt find any info on what controls idle, so maybe anyone have any ideas ?

Thanks !

Dead idle air motor maybe
And bad intank pump maybe in line for gas
Been sitting so I’d replace filter too
But jump power to pumps to see if they fire