hey im going back to the mechanic on tues but what do yous think? i recently got a LPG conversion done, fuel filter and service done at same time. ran a little worse on petrol then. last week got my head gasket done and new valves, ran it on petrol the other day and it ran absolute ****e. felt like it was going to stall, very bad, it was cold if that makes a difference. since LPG done, when running on petrol there is this smell, like rotten eggs or something. gas is not a problem any ideas?
Engine cold or hot? If it was cold, one possibility is that the PCM has 'learned' a new map of (petrol) injector pulse widths using the O2 sensor output while running on LPG. When the engine (O2 sensor) is hot, it is not as noticeable as the O2 sensor is correcting the petrol fuel mix, when cold it is using the learned values without correction. To confirm or refute that, either clear the PCM memory or drive around for a while on petrol and see if the rough running disappears. If an LPG memcal has been used in the conversion, that won't be the problem. If one has been used, stale or contaminated fuel is a possibility but if the conversion is recent I would think not so much.
O2 sensors got replaced with the head gasket, as for the LPG memcal im not sure, i know to check the gas it has its own little port near the glovebox. rough running was when it was cold.
