Heard a bang, guess a backfire, while on LPG...car randomly starts idling at 2100rpm. Constantly making popping sounds, and vibrating epically. Very jumpy on throttle, sometimes smooth just randomly loses power for a second then goes back normal...

On petrol, it's idles stupidly lumpy, normal idle speed but SUPER lumpy...sorta like it's not tuned at all? i'm running a j3 chip(dyno tuned) for petrol and a 6 months old sprintgas system for lpg...

also temperatures were getting high much quicker, causing thermos to keep coming on, i guess this was cos of 2100rpm idle speed....

I had a quick look in the engine bay, couldn't see any loose hoses...but it's dark, and I'm at uni trying to study, dreading the 30 min drive home afterwards :/ got no money so can't afford any expensive parts at the moment...stupid exams so have had to take time off work to study n haven't had pay in a couple weeks...

Any suggestions? It was running perfect before the sudden bang...wasn't even a particularly loud bang, have had much worse backfires before...

edit: Also I feel like a massive tool at traffic lights, car sitting at 2100rpm, making loud popping sounds and vibrating like a b**ch lol...

IT HAS PROBABLY BLOWN THE PLUG OFF THAT GAS FITTER'S PUT ON THE OLD PICK UP FOR THE PCV. ITS UNDER THE T/BODY HARD TO SEE. A 3/8 PLUG WILL FIT IT. ALSO MAKE SURE YOU HAVE A METAL PCV, NOT THE ORIGINAL PLASTIC. FIT PLUGS & LEADS TO STOP YOUR BACKFIRES. USE NGK ZGR6B 11 & CLOSE THE GAP TO .9. [I AM A GAS FITTER] REGARDS TPVM.

Awesome, thanks mate I'll have a look, and yeah I know I need new plugs/leads too just been waiting for some money to come in

Couldn't find a plug blown...BUT. Found that it's running on 5 cylinders, one spark plug was super carbon-covered and the lead is fried...connector bit is broken. Pulled it with engine running and nothing changed lol. So will get a new set of plugs/leads and should run a bit better with all 6 cylinders going