Hi chaps, just bought a Vortx which has been stood for a couple of years. Got it started yesterday and took it for an exploratory spin today. When I first started it the revs shot up to around 7k for a couple of seconds before settling down and idling very lumpily and misfiring a bit. Any ideas why the revs are shooting up like that? Seems to do it every time I start it and it did do it randomly when I lifted off the throttle at least once too.

It's a 5PW engine with a power commander 3.

Sticky throttle at pedal or throttle body?

Dirty injectors ?

sticky choke?

Dodgy power commander map?

If it's been stood 2 years the fuel will have gone off and possibly gummed up the injectors. Drain the tank and put some fresh in along with some injector flush (Forte/Wynns/etc) and make sure the sliders in the throttle bodies are free (liberal spraying with carb cleaner should help).

Thanks for the replies, few things to look at.

The car was completely drained of fuel when I picked it up so it does have fresh fuel in it at least. Amazing how easily it started by the way! Practically first turn of the key once the system was primed.

There'll still have been fuel in the injectors and fuel rail. The latest fuels go very gummy if left; I've seen it almost look like varnish. I'd drain down to minimum in the tank that it'll still run with and add an injector cleaner or two so it's a strong mixture and run it like that.

I think he ran it til it died as it was dry but running some injector cleaner through can't be a bad idea. I do actually have another set of throttle bodies to put on it too as the previous owner thought that might sort the rough running at low revs. I'm not entirely convinced about that but I have them so may as well try it.

Ok, took it for a proper drive today so I have a better idea of the symptoms. Basically it now wants to sit at 5000 rpm all the time so it was like having cruise control when I was on the motorway! When I stopped at lights it would sit at 5k for a good while then gradually drop back down after maybe 30 seconds or more to a reasonable idle speed.

Nothing seems to be catching, throttle butterflies seem to shut quickly.

[Edited on 14/5/14 by T0MMY]

Could it be an air leak?

I had to replace the inlet rubbers on my 5JJ engine last week because 3 where split

As i recall on my 5pw there was a waxstat that operated the fast idle and dropped the revs when warmed up . Could be sticking or faulty although 5k is too fast even for fast idle .

I was thinking air leak and did actually find a few loose clamps on my TBs but tightening them made no difference.

If it was an air leak would the revs eventually drop back to a sensible idle or would it always rev high? I'll try spraying a bit of carb cleaner around.

EDIT: Just downloaded the power commander programme and had a look at the map. First thing is, the throttle position was showing as 55% with the throttle shut. I adjusted the range so it's showing 0-100% now and it seems better...revs hang for just a few seconds rather than 30!

Incidentally, spraying carb cleaner round the TBs didn't affect the idle.

[Edited on 14/5/14 by T0MMY]

Just update this in case anyone with similar symptoms finds this thread.

Recalibrating the throttle position on the power commander combined with lowering the idle has sorted it out. Drives pretty well now barring the clutch which needs work to be usable.