Hi all

Spent most of this summer sorting out the steering on my 1.9Sdi and the day I got it fixed the engine starts misbehaving.

- Idle is fine, no problems

- Accelerating hard, the car is pulling away fine

- At cruising revs the car is losing power, then kicking in again, feels like a rabbit is hopping under the bonnet.

Fuel filter is fine and the timing belt seesm to be okay tension is good.

Anyone got any ideas?

Any lights? Fault code scan might throw something up? Sounds like it could be the fuel pump relay? But that wouldn't normally kick back in.. it'd just die.

MAF?

Coolant temp sender going loopy and messing up the fuel mixture... although this is more common on the 1.4 petrol fabias..

Check EGR flow rates, sounds like an EGR issue as it works hardest at cruise speeds.

Thanks guys.

No MAF sensor on the SDi engine. EGR is a possibility.

Diagnostics showed nothing, but they never have on this engine.

Yup, was the EGR valve. On the SDi engine the quickest way to check this was to pull the power connector from the compensator valve (or whatever it's called) that feeds the EGR. That keeps the EGR closed and the car ran fine, but didn't warm up. Fuel economy seemed to improve a bit though.

Anyway I cleaned out the EGR valve which was caked in carbon deposits and now the car runs 100%. We bought this car 4 years ago at 87,000 miles and now it is just shy of 130k and it has always run a bit hot, but now the EGR valve is cleaned out it is running at a slightly lower temperature so I'm going to add 'clean EGR valve' to my annual to-do list. I'm guessing it has been sticking the whole time we've owned the car.

Another point on the learning curve.