Hi there, could anyone help, I've got a 1.2htp 2008 3 cylinder fabia, 

Starts and drives, but lacks power and does not go over 4000-5000 revs. Also if you rev it on idle the revs drop to 500rpm and then bounce back to around 900rpm. There is no eml or epc light on, I have changed the following:

 

Air filter 

Spark plugs 

Ignition coils.

6-valve or 12-valve?

I'm not sure, but it's a 1.2htp 70bhp 2008 model 

12-valve then. 

Less lkely to be a major problem than if it were the 6v. 

Check the brake servo vacuum hose for cracks where it connects to the non-return valve.

Yeah changed, the vacuum pipe aswell still no luck 

I've managed to get some readings, but are these OK? 

There isn't any power above 4-5k on the 70HP engine, did you just get the car?

Yeah 2 days ago

Manifold pressure seems a bit high, I think.

See what happens if you put your finger over a little hole in the side of the PCV valve cover (while engine is idling).

That's the round thing just behind the chain cover, not far from the oil filler cap.

12 minutes ago, yaz0811 said:

Yeah 2 days ago

 

You need to temper your expectations a bit, it's not a fast car and the little engine doesn't like to rev, as Wino points out there may be an air leak causing the idle instability but other than that there may not be much wrong with the car, it's tuned for fuel economy not performance remember.

So basically it does not go over 4-5K revs at all, even at low rpm it's like there isn't any power at all, and also stalls sometimes when the revs go below idle, and when you rev it on idle the revs drop all the way down to 500-600 rpm almost stalls then rebs go back to around 900 etc 

10 minutes ago, yaz0811 said:

So basically it does not go over 4-5K revs at all, even at low rpm it's like there isn't any power at all, and also stalls sometimes when the revs go below idle, and when you rev it on idle the revs drop all the way down to 500-600 rpm almost stalls then rebs go back to around 900 etc 

 

Ok, sounds odd, suggest you disconnect the battery for a while to reset the ECU, if that doesn't make any difference you should get the engine timing checked in case the chain has jumped a tooth.

Il unplug it over night see if anything changes. 

 

Doubt that'll have any effect at all. The engine ECU is powered via a relay, so you effectively deprive it of all power every time you switch off.

Just doesn't make any sense, I've also checked injectors, they are fine, I've changed spark plugs, coils, Air filter. 

I've noticed you can smell a petrol smell like its maybe running rich or lean? 

Is that the pcv valve? 

 

Yep. Follow that bulge in the lid out to the edge.

Is that's the pcv valve? 

 

Yeah, that's it, but you didn't need to remove it from the engine, just to block that little hole in the cover while the engine was idling, to see if it made any difference to engine running.

I'll try that now

I have tried that with the pcv valve, it didn't nt make any difference 

 

. 

 

Edited 11 September, 20205 yr by yaz0811

So I've replaced the spark plugs with new ones, just took this one out of cylinder 3, is that how they are supposed to be?  After 1 day? 

Edited 11 September, 20205 yr by yaz0811