A really strange problem, any ideas?

[Meallbhan]

Evening all,

Today a friend and I changed the thermostat on the golf.(a 2005 GTI) and was a bit more involved than I had thought. To change it we took the alternator out, so had the battery disconnected.  The battery was undone for about 3 hours in total.  We put in all back together and all went well. When finished, the car coolant was topped up to the correct levels, brought up to temp etc etc.

This is the strange bit.  Driving home the car was getting hardly any boost at all, it was completely flat.  Then slowly it got a bit better and by the time I got home was still lacking in power but far better than when I left.  The mpg took a long time to sort itself out and wasn't returning quite as good as normal by the end of the drive. The car has a revo remap, and at first it felt way less than the standard map, and then after a while it felt more than the standard map but less than the remap if you know what I mean.

While changing the thermostat we had the front diagonal intercooler pipe off at the top and bottom to ease access.  When we got home we thoroughly checked everything we could see around the engine incase we had knocked off a vacuum pipe or something off without noticing.  We checked the intercooler pipe too for tightness and signs of blowing too but we didn't find anything out of the ordinary.

The problem isn't with the thermostat, but something has happened to the cars power and maybe mpg also.

Would having the battery disconnected for 3 hours plus have reset the ecu?  Is it now relearning and will get back to what it was? 

I'm a bit confussed and maybe a little worried.  Any knowledge or advice would be grately appreciated.

I'll find out if the new thermostat has made a difference in the morning when I go for a drive.

[bacillus]

More than likely your revo map has reset itself to stock settings. If this is the case you'll need a sps plus switch to dial in the correct BTF settings.

[Neiltdi]

Im pretty sure as you have a revo map the settings go back to standard when you disconnect the battery

Edit: beaten to it

[Meallbhan]

Oh, thats not good. I hope revo are open tomorrow.

Why do you think the boost got better the further I drove it?

[Meallbhan]

I spoke to vw this morning and managed to speak to one of their mechanics, he said that just by having the battery disconnected for a few hours would not wipe the map and it would just revert back to it as normal.  The two replies I've had just above say the exact opposite.  The car I have to say does not feel like its remapped any more and feels more like the standard map. If this is the case, have I totally lost the revo map and its erased? Or is it still there but I need revo to tell the car to use it again? If its totally gone thats another £600!!  Revo where shut today so I couldn't speak to them.  Can anyone shed any light on this please?  Sorry cant do proper paragraphs as my phone won't let me.

[Baz300]

Where are you located?

There might be a member locally to you that will have a SPS unit and could be wiling to put the settings on for you

[Meallbhan]

I'm in Inverness mate. Even if someone had an SPS to use, it would be their settings I would get not the ones I had in my car. I had the map tweeked by revo after the install. I think my settings are B7 or 8, F9 and T5 I think but cant remember exactly off hand.

[Baz300]

I'm not sure how that works!

I hope you have somewhere local for Revo to re upload the settings

Think it should only be a £50 charge as you have already paid for the map and it will still be on your car, just the settings will all be reset to 0

[bacillus]

I'm in Inverness mate. Even if someone had an SPS to use, it would be their settings I would get not the ones I had in my car. I had the map tweeked by revo after the install. I think my settings are B7 or 8, F9 and T5 I think but cant remember exactly off hand.

If you know your settings, someone with a sps plus switch and a laptop with the revo sps software will be able to put your settings on the sps switch and restore your car's settings. Takes less than 5 minutes.

[Hurdy]

To the OP.

Don't worry about it the car will run fine on base settings. It happened to me a fair few times when mods were being done and I just reset the timings with the SPS+ controller.

[Meallbhan]

I'm starting to feel a little more relaxed about the situation having read the responses. I'm just worried that its gone completely. From what it sounds like the remap is still there though. It may even be running on the remap as I can still hear the dv release where you can't on the standard map, but all the settings are messed up. Yeh I agree the car will be fine on the standard settings. I'm going to order an sps from revo when they open after xmas, just hope its on the 27th as it will be an agonising wait to find out for sure after thd new year!

[GTI-Pirelli]

From what it sounds like the remap is still there though. It may even be running on the remap as I can still hear the dv release where you can't on the standard map

From what I have learned, when the battery is disconnected it will revert to "stock". In the case of a REVO re-map "stock" is REVO's settings that closest match VW's map as it was shipped, so there will be slight differences such as DV noises. When re-mapped it will no-longer have VW's map on the ECU.

Please correct me if I'm wrong.

[Meallbhan]

I'm led to believe the golfs ecu has 2 sides, like an open book. One side has the vw map on it as standard and the other side is blank. This is where the remap goes, enabling you to swap between your maps when you wish, like if you have an sps. But I dont know whats happened for sure yet but what you say makes some sense.

[Hurdy]

When the battery is disconnected the settings return/default to boost, fuelling and timing 0 settings, which is Revo's own version of stock. The car doesn't revert back to the VW settings as they no longer exist on the car.

[Meallbhan]

Does the battery have to be disconnected for over a certain period of time for this to happen or is it instantaneous? A right pain in the butt either way. Must be a scam by revo if this is the case.