My '95 4.0 Cherokee has an LPG conversion. There is a selector switch giving
the following options 1-Petrol..2-LPG..3-Start using Petrol automatically
switch to LPG shortly after starting. I've been advised selecting 3 is the
best option.

Cold starts do not seem to be a problem. However starting when engine is
warm either switch position 1 or 3 is murder! The engine miss-fires and runs
rough. Obviously a problem with the Petrol feed. Switching to 2 and all
seems fine (so far) as does switching to 3 after the engine has been running
for a couple of minutes.

It seems obvious the problem is running using petrol. Have any of you any
ideas on where to start looking? I assume the electrics are fine as all runs
well using LPG.

Any suggestions would be appreciated, along with where to look for the parts
that might be faulty/blocked. I've only had the motor a week and a bit so
the geography under the bonnet is alien to me

I need help!

Cheers, Ray