idling issues, 4.2 carby

[sunnycoastGQ]

my new rig has decided it doesnt want to idle below about 1100rpm all of a sudden and the other night leaving work it died in the car park and wouldn't fire again, its seemed to have no spark, the next day when i returned with tools to find the problem it started straight away so i didnt get a chance to figure it out, no idea what the go is???? has anybody had these problems before? the carby is a reco unit not long ago so im thinking ignition system but the idle thing has me stumped if it stalls it doesnt start again for ages then just starts again easliy at random!

[90mav]

Is it LPG or petrol? The idle problem sounds like a vacuum leak.
Start from basics, to have the engine work you need 1.compression (which hopefully you have), 2.timing (valve and ignition), 3.spark (which you have or not?), 4.petrol
Check to see if the coil is getting hot. If it is getting hot it will break down. When you leave it to cool a while it will start working again.