Misses while idling

My '95 XJ starts perfectly and runs very smoothly, but, while idling it tends to miss every few seconds. It's not a big deal as it doesn't cut out but you certainly do notice it. Any suggestions as to what it could be?

You might check for an intake manifold leak, 4 litres have a history of manifold problems. My xj was acting similar and I found a leak at the rear of the intake maifold. got a new intake/ exhaust gasket from the dealer,installed it and it is running great now

check for a cracked plug wire also

my 96 was doing this occasionally before the fuel pump finally died on me.