So my 2.0 MPI is fully serviced and the rolling chassis is completely upgraded with a B12 setup, all the bushes and balljoints, top mounts and bearings have all been replaced. Handling not an issue.

It has 288 brakes as standard and these have been redone front and rear with Pagid discs and pads, the brakes are excellent compared to the 1.4.

 

I've changed the oil and all the filters, the plugs and leads and replaced the CTS sensor because it was starting like a pig, it's now much better but it won't start from cold unless you press the throttle pedal a bit, if you don't it just dies before it catches, once it's warmed up a bit it idles smoothly but in all situations it hunts on tickover but is noticeably worse when cold. I'm not hugely inconvenienced by this but it is irritating as the 1.4 was much smoother. It is however quicker than the 1.4 although thirstier when provoked, but not bad at all on a run, comparable in fact.

 

Apparently Golf 4 GTI's suffer with this as well, the only real difference with the Fabia is that the throttle body has fully electronic stepper control rather than the Golf which has a throttle cable, is it just a feature of the ancient 8 valve engine or can something be done about it? My brothers Golf 4 2.0 estate was much smoother with no hunting at all.

 

I'll be putting an ABF into it in the summer and I still have the 1.4 parked up for when I decide to do the transplant, meantime the ABF is waiting in the workshop so I can give it a refresh rebuild and rework the head before fitting it. Going to use a VR6 clutch so I can abuse it safely and may decide to fit an ATB diff once I migrate to throttle bodies and the full 200 BHP, meantime 170 BHP is what I'm expecting after the refresh and headwork.

 

So if anyone has experience with the vile 2.0 8V lump and its lumpy idle I'll be grateful for any advice, VCDS says everything is tickety-boo but it's just not right.

Sounds like a throttle body clean and reset to me

Normally it's either an air leak or as said an issue with the TB. Have you tried basic settings with VCDS?

Also love the idea of the ABF, something I had considered before now.

Check the VCDS readings on the CTS before trying to start the engine, at cold. My 1.4 mpi wasn't a happy starter at cold. I've replaced 3 brand new OEM sensors.

It was a loose plug cap combined with a leaky vac pipe from the FPR, no hunting now although it still won't start without some throttle.