Hi guys,

 

My Mk1 vRS is remapped, I think it's quite an aggressive map as it does less MPG than my last one. All I seem to do is sit in traffic and it guzzles fuel doing that, it's not uncommon to sit at about 15mpg on my short 2.5/3 mile commute with a bit of traffic. The old one would do 10mpg or so more and I was just wondering if there's an easy way to return the map to stock myself? If not, do Skoda do it and how much do they generally charge?

Ta

 

I think this would be worth exploring more before you go back to basic. It could be a mapping issue as fuel trim may be off as a result of how it's written. Or it could be nothing to do with the remap at all, something else may be causing the car to run rich. If there was no inherent issue with the map, in itself it wouldn't effect mpg so detrimentally in those circumstances in terms of how aggressive it is. That mpg does sound low...Could be worth getting some logging done to see what the fuel system is doing. Might also be worth a scan, a code could have been logged without necessarily lighting up the EML.

Most tuning companies will be able to put a stock map back on. But like Yellow said above their may be another issue.

What's the coolant temp doing? It might not warm up during your short commute and the ECU will just tip fuel in to try and get heat into the engine. Will take even longer and more fuel if your stat is stuck open, especially with the colder mornings.

What's the coolant temp doing? It might not warm up during your short commute and the ECU will just tip fuel in to try and get heat into the engine. Will take even longer and more fuel if your stat is stuck open, especially with the colder mornings.

I was thinking sticky stat related, that run wouldn't be long enough to show up any real anomalies like overcooling etc, unless it was taking a while to get up to temp and the heater is a bit slow. How are those things behaving?

In fairness the temp does take a while to get to the middle, most of the time on my journey it gets about half way. There aren't any error messages popping up which I thought there would be if it was a stat issue?

In fairness the temp does take a while to get to the middle, most of the time on my journey it gets about half way. There aren't any error messages popping up which I thought there would be if it was a stat issue?

 

 

There's your clue, the stat doesn't give a code as it's mechanical rather than electronic, it will use more fuel as it's not heating up the engine properly which in turn causes the ecu to throw in fuel in attempt to get it up to temp.  

Awesome! It's due an MOT in a couple of weeks, I'll get the stat changed at the same time!

Does the temperature move up and down?  It should be upto 90 within a few miles really..

Does the temperature move up and down?  It should be upto 90 within a few miles really..

I don't think on his work run he drives far enough or goes over enough varied roads to see it drop when off the gas.

New stat definitely worth a try here.

3 miles should be enough to see it getting close to 90.  take it for a longer run and make sure it does get all the way to 90, if not then the stat needs replacing - PITA to do and you need ratchet set with funky angled bit or ratcheting spanners to make it easier.

 

What you need to do is get it scanned by someone with VCDS and measure block 32 which is the fuel trims, they are a great indicator if you have boost and vac leaks which WILL cause poor consumption as well as other issues.