Just wondering if anyone can give me any clues as to how to get my Vortx R1 to behave itself?

Basically it is very hard to start from cold and then eventually gets chugging away sounding like it's running on 2 cylinders. When you give it some throttle it actually runs sweetly once the revs rise a bit...the problem is just at very low throttle openings and low revs. I've tried tugging off coil packs and it does indeed seem to be running on 2 when cold and at idle revs, although it is getting a spark on all cylinders.

When I bought it I looked at the PC3 map and the throttle position was all wrong, reading open when the throttle was closed so I recalibrated it and that helped the initial problem it had of revving up to 5K randomly but hasn't made it run perfectly.

Also it kangaroos a bit on a light throttle and when initially started it makes some alarming pops and bangs for a while, which go away once it's warm.

I was thinking about balancing the throttle bodies but if that's not the issue I thought it would be counterproductive to balance them with the engine running poorly for another reason.

Any thoughts on what I should look at?

Incidentally, it was easier to cold start before I put some Redex through it...now it's worse. Don't have much faith in such things but it was very cheap in Tescos so I thought I may as well.

[Edited on 28/6/14 by T0MMY]

It sounds like balance required to me, when it starts which cylinders remain cold, if it's a pair tied to a throttle body then you have the problem.

Had a go at syncing the TBs today...they didn't really seem very far out at all to be honest. I did discover I have an air leak around one of them though, by spraying carb cleaner around again. To be honest, with the engine nice and hot it doesn't run too badly at all. So an issue that only affects it when cold...

Iirc the cold start and fast idle is controlled by a wax stat that has water pipes that go to it under the throttle bodies.

That seems the next thing to check then. I'll have to read up on it...I think I know the bit you mean but no idea how to diagnose a fault with it as I've never encountered one before!

might be stating the obvious.... have you tried a new set of spark plugs?
My engine has had similar symptoms before and a new set cured it

Actually I haven't. It's got them thar fancy iridium plugs which I thought were meant to last for ages. Might be worth trying it. The other thing is the battery is very weak which can't be helping, although when I started it with jump leads the other day it was just as hard to start.

Incidentally I just checked through the workshop manual and the thermo wax system doesn't seem to be mentioned at all! How do you diagnose a fault with it?

[Edited on 30/6/14 by T0MMY]