Leon 2003 1.4 S 16V, temporary loss of power

[stonkle]

Hi There,

I am experiencing some issues with my 2003 1.4 16v Leon. They are intermittent, but seemingly growing worse.

For a long time it has been idling erratically. You will start the engine and it will sometimes run a bit fast for 5 mins or so (1200) then settle down. More recently it has begun running on the slow side and the revs jump and dip as if it will almost cut out (in most cases you give it a bit of gas and it drives fine). This has been troubling me more since the dips. I thought maybe something to do with timing, idle timer or fuel pump?

A few times now I have been driving at relatively low speed, the battery light has come on for a a few seconds, the power has dipped, power steering has died and then it kicks back into life of it's own accord. As you can see this has gone from an annoyance to a danger and I would like to get it sorted out. I have read that some people have solved similar problems by replacing the throttle body and doing a reset. I have also read of issues with the belt that runs the power steering (but that must be ok as it is intermittent?).

My local garage seemed a bit perplexed when I mentioned replacing the throttle body - I just wanted to check on here before I take it to the garage.

Appreciate any comments - especially if you have experienced this issue.

Thanks

[Sam]

Welcome to VWAF :)

Rule #1 of diagnostics is start with a code read.

Idle issues are often caused by a faulty coolant temperature sensor. Stalling could be an engine speed sensor/crank sensor. Without a code read, we're peeing in the wind.

[stonkle]

There are no warning lights showing - but I guess that does not mean there aren't any stored codes.

I don't have a reader, I know the coolant temp sensor can cause issues (I did buy a replacement - but have not fitted it yet). Was just checking if the battery light and loss of power was a common issue.

Ta

[zollaf]

battery light and loss of pas mean its stalled, so must be doing it when you put the clutch down, unless you make a habit of coasting down hills.

[stonkle]

Ha, no I am not into coasting.

Just read this: Engine EPC and Electric Diagnostic Lights & 'Silent' Stalling - SEAT Cupra.net - SEAT Forum (http://www.seatcupra.net/forums/showthread.php?t=233371)

Throttle body possibly.

[Col]

First thing to do is sack your garage then;

Get it read for fault codes, if there are none then;

Do not buy a new throttle body, clean existing one and then have it electronically aligned. The alignment must be done. There is plenty of info online about throttle body mischief, some of which you have found already. Don't buy a new one, yet.

Also, don't attempt to clean it on the car as some people may advise, you will never be able to do it properly without taking it off the car.

[stonkle]

OK, yes the garage have had ample opportunity to resolve the idling, I have given them clues and asked them to look at it.

I have got a Autel ms309 on the way. Hopefully this will get the codes (my BIL has one and it has previously proven useful on this car). I think I have some carb cleaner.

Not sure how I'd get it electronically realigned? Does it not relearn itself after about 20 miles?

Oh and Thank you!

[Rob69]

Your MS309 will not be able to perform the throttle body realignment, you might be able to measure fuel trims etc but you'd need VCDS to do alignment .

[stonkle]

Thanks.

MS309 arrived, have checked for codes and there are none stored. I got some wynn's air intake cleaner. Gonna see about taking the throttle body off for a thorough but gentle clean assuming I can find somewhere that can do the realignment for me.

If anyone is in Swansea with VCDS and fancies a modest reward (beers/wine/cider) - please let me know!

Ta