I’ve recently fitted a 190 ECU and sprocket to my S1. The ECU was used but I’m happy that it’s off the right car etc. and I know, I should have fitted an Emerald blah, blah…blah!
Before I start to get too involved with my issue, I thought I’d ask for some pointers;
The issue I have is that when stationary the idle speed is fine and is around the 1200rpm mark. But as soon as the car moves off i.e. detect wheel speed the idle raises to just over 2200rpm, stop and it drops back to normal. This can be simulated back raising the car and then rotating the rear right wheel manually whilst the car is idling and the rpm increases immediately!
Mine used to do this when cold, such as when backing out of the garage. Although after reconnecting the battery after replacing my alternator mine’s doing this all the time too… it idles at about 2000RPM until you come to a complete halt. I’dbe interested in hearing the answer too.
Try disconnecting/cleaning the speed sensor on the rear left hand hub.
Cheers Rob.
The rpm only increases when you spin the right rear wheel, do you mean clean the sensor on this hub?
I’m probably confused, Mark
Why not pull em both apart, clean the electric connections, & spray with WD40.
IIRC the left hand side sends a signal to the Stack speedo (& ECU?), & the right hand side controlled the fueling (via ECU) on the overun. So, you’re probably correct to concentrate on the right hand side one
Good luck - hope you get fixed for the Oulton LOT trackday in June!
Could be that the confusion is which way you are looking at the car ??
Nearside wheel sensor is speed sensor.
Offside sensor is the other one that can affect the 5500 limits etc…
Sorry to confuse everyone. I work for a German car manufacture and to save any misunderstandings always quote right or left. Right side being offside. The engine most certainly rises when the right/offside rear wheel is rotated and idles normally when the wheel is stopped.
I’ll check the sensor, as per Great Great Grandad’s first post!
Don’t worry, I was probably incorrect in my first post. The offside rear (ie UK driver’s side) is the overun/5500rpm sensor, & that’s the one which is possibly playing up.
My 190 did that as well, as soon as you move revs rise - I thought it was a CAT thing for emmissions until it got warm - as in the ECU detected a certain water temperature.
My 190 did that as well, as soon as you move revs rise - I thought it was a CAT thing for emmissions until it got warm - as in the ECU detected a certain water temperature.
Sticking revs usually a IACV sticking ?
Yeah, I think it’s MEANT to do it when cold, but since had the battery disconnected mine’s been doing it when it’s hot too. Is there a procedure on the 190ECU for resetting the IACV?
Yeah, I think it’s MEANT to do it when cold, but since had the battery disconnected mine’s been doing it when it’s hot too. Is there a procedure on the 190ECU for resetting the IACV? [/quote]
Yes even when the engine reaches normal operating temp, the rise in rpm is apparent. I too disconnected the battery to replace the ECU.
I’ve not yet checked the wheel speed sensor, however, I little bemused with how the could cause the compliant, as it is detecting rotation! I’ll spend sometime over the weekend looking at it in more detail and report my findings.
I just wonder if the EXU does that for a while automatically while it’s “learning” again after being reconnected, or whether there’s an IACV-resetting procedure like there is with the standard car (five full throttle openings with the ignition on and engine off) that should be donw after reconnecting the power.
My car’s coming to bits for the winter so I’m in no hurry to find a solution but am still interested to find out what the heck is going on.
Like you say, sensor doesn’t seem at fault because it’s doing what it should, the ECU doesn’t seem to be reacting normally to the signal.
Did anyone manage to get an answer on this? Mine is now doing exactly the same thing … unless it is at a complete standstill, it idles at about 2200 … very irritating.
Mine used to do this too! Found that if I allowed it to warm up until I got water temp on the ‘Stack’, then blipped the loud pedal, the idle speed went down… Bit of a pain though… so got an Emerald!!
Did anyone manage to get an answer on this? Mine is now doing exactly the same thing … unless it is at a complete standstill, it idles at about 2200 … very irritating.
Since I last posted on this subject I have not had an opportunity to check my car over. I should have some time next weekend! Will post when/if I find the problem.
Cheers Mark. Interested to hear if you find anything. I’m in no hurry as my engine’s coming to bits in a week or so, but will probably need to get to the bottom of the problem come springtime down 'ere.
Cheers Mark. Interested to hear if you find anything. I’m in no hurry as my engine’s coming to bits in a week or so, but will probably need to get to the bottom of the problem come springtime down 'ere.
Sorry for the delay in posting a response on this, but had my S1 in at the paint shop having all the stone chips sorted! Looks grand now…
Anyway, problem sorted!!! i removed the wheel speed sensor from the right rear wheel to checked for damage, pin contamination etc. No fault found, refitted and centralised the sensor. Continued with functional test to recorded exact rpm increase, with and without air-con on, and could not replicate the fault. Since then, been out in the car a few times, and it’s spot on! Great Britain engineering, you can’t beat it…only joking!!!
I hate it when Great Grandad right all the time, cheers Pesky. Look forward to catching up at Oulton.
Will be great to meet up with you & Phil again - it’ll make a change from bumping into your dad, whilst charging up & down the aisles at Tesco in Horwich However, come to think about it, he’s always hovering around the shelves stocked with gin