VS V8 idle query

[stockyvrcalais]

Hi all, the last couple of days i have noticed when engine in my car (its a VS series 2 V8)
is cold it has a weird idle, the idle will go up and down by a couple of hundred revs, no matter if in gear or not, but once it warms up a little its fine, anyone come across this before? Thanks in advance.

[Cobez]

Fitted a bigger throttle body or anything lately?

If not, give the throttle body a good cleanout on the inside, rev your car up to 3k, hold it for 10 seconds then release the pedal. See if that fixes it. If not, could be a vacuum leak. Mine did it, then i found a split in the fuel pressure reg vacuum line (one of the two small black vacuum hoses that runs under the manifold on the 5 litre).