Vauxhall Corsa E Forum banner
1 - 20 of 24 Posts

·
Registered
Joined
·
2,902 Posts
Discussion Starter · #1 ·
Since turning off my faulty/lethal S/S I've noticed a couple of odd side effects.

One is that car is more responsive from lower rpm when pulling away from junctions and onto roundabouts.

The second is more bizarre - normally the 1.4T 100PS has a fuelling restriction at approx 4K rpm which prevents any more power being generated above that rpm. This forces a change up in order to maintain acceleration. Not normally an issue as most of the time I change up at 2000-2500rpm anyway. However on the odd occasion where I've floored the throttle to overtake I've noticed that my 1.4T (with S/S disabled) revs right upto 6Krpm and continues to produce significant acceleration above 4K rpm.

Has anybody else noticed this or is it yet another fault with my cars electronics? Not that I am complaining as it makes the car more powerful. However I'm curious if the fuelling restriction only applies when eco mode is enabled (default).
 

·
Registered
Joined
·
1,612 Posts
It makes sense that Eco mode restricts the rev range, but have you noticed a drop in economy with Eco mode off?
 

·
Registered
Joined
·
2,902 Posts
Discussion Starter · #3 ·
Actually, I have noticed a drop BUT my commute is mostly (250 miles) motorway and dual carriageway with very few actual stops at roundabouts or junctions so it can't be down to S/S being disabled?

I had just put the drop down to weather. Since turning off S/S every time I get in, it also happens to have been getting darker earlier and colder so I'm now running with lights and heater on virtually 100% of the time.

I used to be able to get 70mpg on the motorway at 60mph but now I'm struggling to better 60mpg. The only reason my fuelly average is going up is because my wife has her Land Rover back on the road so is not using Dafny much. ;-)
(even only getting 60mpg is still better than her 48mpg.....)
 

·
Registered
Joined
·
1,665 Posts
A number of my Vauxhalls had a Sport/Eco switch which must have done the same, particularly the automatics where the gear changes were 2000 rpm higher!

No VW would have bigger gear on the mileometer so you think you are going further than you really are.

I wouldnt like to be the programming team that wrote the VW defeat code! All they need to do now is keep the Adblue pumping in all the time and top it up more often. That will be the recall fix I reckon.
 

·
Registered
Joined
·
2,902 Posts
Discussion Starter · #5 ·
AFAIK the 'eco' button on the dash simply switches off Stop/Start. I'd be surprised if it unlocked a different ECU map unless mine is actually faulty and I've stumbled across it by accident. There is no documentation that I can find. It certainly now has more power at 4-5K rpm whereas before it had nothing. So something has changed but in fairness I can't tell if it was always like this or it has happened just since the S/S failure because prior to two weeks ago I always left the eco button enabled and was quite happy with the s/s as it seemed to work brilliantly. I'd estimate the increase in power on the few overtakes I've done recently to be something like 10-15hp. Not a huge hike but just enough to be noticable and of course the obvious thing is that it now revs right upto 6K rpm whereas before it hit 4K rpm and acceleration stopped virtually dead.

PS. Is that what they did? simply add adblue to the vehicles having the official test? You would have thought a lab test would have used their own controlled fuel and checked for traces of such additives in the fuel lines?
 

·
Registered
Joined
·
1,665 Posts
the defeat software increased the Adblue urea concentration only if it detected the test equipment. urea combines with NO2 to produce N and probably water.
 

·
Registered
Joined
·
2,902 Posts
Discussion Starter · #7 ·
Jarviser said:
the defeat software increased the Adblue urea concentration only if it detected the test equipment. urea combines with NO2 to produce N and probably water.
Ah right, I guess the ABS/Traction control sensors would detect that both front wheels were spinning (on the labs rolling road) while the rears where stationary. If it works that well at lowering nitrogen oxide levels why don't they just run with it all the time? Is there a performance cost or is it purely additional manufacturing and maintenance costs that they are trying to avoid I wonder.

I assume HGV's have to use it as I see the adBlue at nearly all the big petrol stations now.
 

·
Registered
Joined
·
2,902 Posts
Discussion Starter · #8 ·
Found the answer Jarviser, to last 18K miles of driving (typical VW diesel service interval in UK) you'd have to carry approx 45 litres of AdBlue so effectively another tank the size of the fuel tank! That would be a major engineering re-design for some smaller cars such as Polo/Golf etc. On top of that you'd have to pay an additional £60 for AdBlue on every service.

Glad I bought a petrol ;-)
 

·
Registered
Joined
·
126 Posts
With the Eco off I'd say the car acceleration is much soother and the throttle feels more responsive.
Starting to think that the Eco button is more than just S/S.
 

·
Registered
Joined
·
961 Posts
ANTsting-R said:
With the Eco off I'd say the car acceleration is much soother and the throttle feels more responsive.
Starting to think that the Eco button is more than just S/S.
I doubt it, I regularly drive diesel Astra and Insignias with start/stop and an eco button and it makes no difference to performance whether it's on or off. Astra Hs used to come with a "sport" button which improved throttle response etc (in reality it didn't, you just had to not put your foot to the floor as much to boot it, so it just made throttle pedal more sensitive) but I doubt the Eco switch has that capability.
 

·
Registered
Joined
·
1,357 Posts
hendry said:
ANTsting-R said:
With the Eco off I'd say the car acceleration is much soother and the throttle feels more responsive.
Starting to think that the Eco button is more than just S/S.
I doubt it, I regularly drive diesel Astra and Insignias with start/stop and an eco button and it makes no difference to performance whether it's on or off. Astra Hs used to come with a "sport" button which improved throttle response etc (in reality it didn't, you just had to not put your foot to the floor as much to boot it, so it just made throttle pedal more sensitive) but I doubt the Eco switch has that capability.
I'm not so sure.

I think it may do more than S/S. Me, Mud and Ant experience similar, if not the same things when ECO is off - Improved acceleration, increased torque in higher revs and smoother to boot.
 

·
Registered
Joined
·
2,902 Posts
Discussion Starter · #12 ·
You can't compare diesel to petrol anyway. Completely different systems.

Also 1.4T is deliberately fitted with a fuelling restriction at 4K rpm to limit power. It would be a 120PS engine without that restriction simply because you have an extra 2K rpm before you hit peak power. In my case since my S/S went berserk and nearly killed me, my engine no longer has a fuelling limit at 4K. It revs cleanly to 6K and continues to accelerate above 4K which it never did before. Clearly this is a fault, somehow the ECU settings have been corrupted. In theory my engine will now be a 120PS unit. It was already measured on a dyno at 112hp* (115PS) before the S/S failed and that was at 3800 rpm. I will take it back soon and get it tested again if it looks like it is permanently 'unlocked' to 6K rpm.

I don't think the eco button is meant to unlock the fuelling restriction otherwise it could affect insurance as you'd be insured for a 100PS but with the eco disabled you'd be on 120PS!

I'm pretty sure something broke internally in its programming, not sure what or how but I suspect it will have to be fixed as I suspect a damaged sensor is to blame. My trip keeps showing big variance in mpg from actual and I've also noticed this week that the speedo and odo needles randomly drop to zero while driving along and then go back to what they were!! It happens so quickly that at first I thought it was my eyes playing tricks but I've seen it do this several times now.

*dyno can be upto 10% out though so only useful for comparing before and after on same car.
 

·
Registered
Joined
·
1,357 Posts
Wow, sounds like you do have some pretty major issues there mud!
 

·
Registered
Joined
·
2,902 Posts
Discussion Starter · #14 ·
LimeyUK said:
Wow, sounds like you do have some pretty major issues there mud!
Yeah, typical modern technology - bloody useless unreliable junk!

I wish I could just buy a new simple, basic car with no electronics on it but sadly the EU has mandated most of this nonsense.

Dafny will be handed back after her PCP finishes - if I'm having this many electronic issues this early in her life I don;t want to keep her beyond the 3 years. In fact since posting about the S/S issues the other day, the central locking has now started playing up too. Having to lock the car with the key now because the key fob is unreliable.

Dafny is already far more unreliable than our 30 year old Land Rover and she is only 5 months old. It seems that once she got past 10K miles on the clock all her electronics started falling apart.

In comparison the Land Rover has only had two faults in 5 years (headlight wiring broken connection on 30 year old wiring, leak on 30 yr old brake M/C)
 

·
Registered
Joined
·
1,357 Posts
It might be worth notifying your dealer about the issues - even if you don't have them sorted.
 

·
Registered
Joined
·
2,902 Posts
Discussion Starter · #16 ·
I'm taking it back in a few weeks time. Dealer is miles away and I don't have time to go yet as I'm at work during the times they are open.

Getting quite fed up of all these electronic problems now.

We've stopped driving Dafny other than for my once a week commute and are now using the old Land Rover for every other journey because it is safer and more reliable!
 

·
Registered
Joined
·
2,902 Posts
Discussion Starter · #18 ·
I'm going to have to take a video of this, absolutely loving the performance increase on my car :cool:

Tried it several times this morning and every time my engine revs right up to 6K rpm and delivers a huge wave of power from 2.5K to 5.5K rpm, acceleration is now very swift and it is stupidly easy to exceed a speed limit from a blip of the throttle.

I will try and mount my phone on my drivers door so it can capture the speedo and odo while I drive. It definately has changed. The engine never revved above 4K rpm before and never felt this powerful either. Fuel economy is down though, really struggling to get even 58mpg on the trip despite cruising at 56mph!!! It used to show 70mpg at that speed before. How on earth the ECU map can have changed I have no idea but it almost certainly has! It only does this with eco turned off though, if I turn eco on then it behaves as it did before. (and cuts out all the time too)
 

·
Registered
Joined
·
73 Posts
mine revs no problem up to 6K with ECO on. didn't no that the eco had a rev limit !!!

mud4fun said:
Since turning off my faulty/lethal S/S I've noticed a couple of odd side effects.

One is that car is more responsive from lower rpm when pulling away from junctions and onto roundabouts.

The second is more bizarre - normally the 1.4T 100PS has a fuelling restriction at approx 4K rpm which prevents any more power being generated above that rpm. This forces a change up in order to maintain acceleration. Not normally an issue as most of the time I change up at 2000-2500rpm anyway. However on the odd occasion where I've floored the throttle to overtake I've noticed that my 1.4T (with S/S disabled) revs right upto 6Krpm and continues to produce significant acceleration above 4K rpm.

Has anybody else noticed this or is it yet another fault with my cars electronics? Not that I am complaining as it makes the car more powerful. However I'm curious if the fuelling restriction only applies when eco mode is enabled (default).
 

·
Registered
Joined
·
73 Posts
I never new that there was a rev limit with the ECO on. my will happily rev to 6K with ECO on. looks like I have a fault then LOL.
 
1 - 20 of 24 Posts
Top