Hello all, Ive only posted one or twice as Im new to the skoda world.

 

Ive manged to solve most of the little problems, resoldered my cluster, sorted boot lights ect. But one that keeps cropping up is, Every so often when ive been traveling at a constant speed for 2 or more miles as im braking (not using gears) The engine will drop to idle and the slightly slower than idle speed and judder until I take my foot off the brake and Im not demanding anything from the Vac system again. It will then find a stable idle. I have replace one vac line as it was leaking and I lost my vac brake assistance.

 

Could this be caused by an air leak?

 

Any thoughts facts and opinions welcome

Sounds like there still a torn vacuum hose some where, Try listening for a sucking noise coming from the left hand side of the engine.

You din`t say whether it had any mods on it? As some cheap fleabay items can cause more grief than you would believe on these 1.8t.

Also you never mentioned diesel or petrol?

Edited 17 November, 201312 yr by skud missile

Thank you for rifling through my exceptionally poor post.

I have no service history but the previous owner didn't seem like the modding sort of person. Its a 1.9tdi with 1 red letter but is listed as a 90hp.

I shall have a fettle in the week, my trip computer tells me im getting about 56mpg over a tank full but real world maths makes it 53 something is slightly a miss

53mpg is respectable given the current cold weather. You will find it will increase in warmer weather, I blocked my rad off last year but I don't think it makes a huge difference on modern cars to be honest.

 

I think my TDI110 ASV block gets about 54mpg on average, I don't do many long journeys any more though. 

 

 

edit: oh and the real vs computer reading is about the same as the difference in mine.  

Edited 17 November, 201312 yr by yesiamtom

ah ha! thats good to know then. So not looking for any sort of serious fault then just curious to know whats causing the lump idle. 

 

My daily run to and from work is twist b road stop start. Thats where i get my 53, on a motorway run I can happily get 60!

 

Where is the block number? Might give me a clue what engine ive really got.

Ah a diesels. Not much experience with them but regards to your lumpy idle might be MAF related.

Try and unplug the MAF and see if the idle gets better as when the MAF's is un plugged it uses a default setting in the ECU.

Don't diesels have a idle control valve that gets sticky after a while?

Edited 17 November, 201312 yr by skud missile

sticky turbo vanes skud? Thats common but shouldn't have happened on a 90bhp.

 

MAF is a good shout though.

Cheers for the tips guys. My turbo spins up exceptionally well for a car of this age. I can only assume its had a new one in the recent past. I can hear it very well from inside the car about 2500rpm.

 

I will certainly have a listen for some vac leaks and try unplugging the MAF during the week.

 

is it really a 90hp if its got a red i? my understanding is one red letter is 110hp? 

Couldn't tell u but it's just a badge so wouldn't loose any sleep over it. The Main differences I believe is the map varies from no red lettering to red TDI.

It might of had a generic map of fleabay if it feels more power than 90brake.

Just curios more than anything. Long as it keep doing over 50mpg i shall be grinning all the way to the bank! Got a few jobs to do, new front ARB bushes, crunchy rear brake drum to sort out and a NSF wheel hub to swap over for and the car needs a damn good clean inside. that on top of this idle problem should see it all set for a good year

Every so oftern I get the same from my Octavia TDI, I will have to check the vacuum hose's, there are a couple that do look alittle worse for ware.

 

I might get some silicone vacuum hose and replace them all to be on the safe side.

 

Anyone know what diameter vacuum hose is needed?

Ive been using this for a few years

 

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=190714859479&var=490093392992

 

sure its 3mm that ive been using

I have had a good listen, I cant find any leaks. Though Ive lost one or two MPG recently so something is up.

 

Where is the EGR valve on these?

 

I have had a good listen, I cant find any leaks. Though Ive lost one or two MPG recently so something is up.

 

Where is the EGR valve on these?

 

It's winter...MPG does drop.

when my car judderred at slowdown it was overfuelling slightly... i used vagcom to tweak it down slightly

It's winter...MPG does drop.

 

 

Good point, well made

 

 

when my car judderred at slowdown it was overfuelling slightly... i used vagcom to tweak it down slightly

 

 

Did you have an error code? I have non present so Id like to give the EGR a clean. I assume its the valve at the back of the engine on the left?