Hunting idle, Sigma150

[beejay993]

Wondering if anyone can offer me some advise...my Sigma 150 has developed a rough idle, whereby it sometimes gets close to cutting out, before eventually finding itself again. I would say it's idling lower than normal however...

The other strange thing, sometimes when starting the car it struggles to fire up, and when it does, it runs with a severe flat spot, before clearing itself, alternatively, if I shut it off and start it again, it's normally fine ?

Any ideas as to where to start ? It's worth pointing out it does have the usual 150 flat spot, and the nice pops and bangs that go with it, but at present it's worse than normal...

[Dr Slotter]

Tried resetting the TPS?

[framerateuk]

My Sigma 140 did this when I bought it. It would start fine, then start hunting a little, the more until the revs dropped enough to stop the engine. After restarting it was usually fine. Sometimes I found holding the throttle a little after starting the car overcame the problem.

I asked my usual garage to look at it; he changed the spark plugs and adjusted the throttle (I assume to let a little more air in on idle). It's been fine ever since.