Premature limiter

[RichQuy]

Afternoon

I posted a while back re the revs in my car (S2 111S) sometimes fall short of the 'peak power' point, i.e. rather than revving round to 7,200 it occasionally cuts short at around 6,000rpm and takes me by surprise.

I can't really work out why. Some suggested re-calibrating the binnacle (mine's not Stack but another brand - sorry can't remember at the mo), but that didn't seem to have any effect.

Could it be something like the ignition coils or leads??! The connections do not seem brilliant anymore on these (nearly 4 years old) but before replacing I want to know whether or not they could be the culprit?

Any other suggestions?!

Thanks in advance.

Rich

[hbaumhardt]

Typically this is the Black ECT coolant sensor playing up. Unlike the S1, the S2 uses a combined ECU/readout sensor, so whats the temp readout on the instruments say when your rev limited ? If its faulty its only £15 form eliseparts to find out.

[cheekymonkey]

I would have thought more likely the variable rev limiter... i.e the engine is not warmed up sufficiently to allow full revs.

[RichQuy]

Thank you for the responses.

I MUST stress that this occurs well after the car is warmed up, i.e. at the weekend had been driving for around 35mins before attempting full throttle and then hitting the premature limit. I never do this during the initial warm-up phase (Besides, from reading a while back, the limit imposed before the car is warm is around 4.5k rpm).

Hans, I like your description and sounds as if you may have hit the nail on the head. In my post weeks back I spoke about the low running temp. Even after 30mins driving, the temp readout is lucky to be 77 degrees, when 'pressing on' it can drop to around 73, and then will return to 77/78. I had the pro alloy motorsport rad fitted a few months back (plastic connector failure) and put this lower running temp down to that as thought it would be more efficient. Prior to the new rad it would constantly sit at 84/85.

[hbaumhardt]

Yar, I lost the ECT signal racing at Spa and got rev limited to 6k rpm. The VVC oil temperature related limit is lower at around 5k rpm.

When changing the ECT sensor, depending on your pipework, you may find it a LOT easier removing the undertray and going up from underneath.

[RichQuy]

hbaumhardt said:

Yar, I lost the ECT signal racing at Spa and got rev limited to 6k rpm. The VVC oil temperature related limit is lower at around 5k rpm.

When changing the ECT sensor, depending on your pipework, you may find it a LOT easier removing the undertray and going up from underneath.

Thanks Hans, you've been very helpful. Will have a crack at replacing it and hopefully this will be the end of it!

[Mikey_W]

RichQuy said:

Thank you for the responses.

I MUST stress that this occurs well after the car is warmed up, i.e. at the weekend had been driving for around 35mins before attempting full throttle and then hitting the premature limit. I never do this during the initial warm-up phase (Besides, from reading a while back, the limit imposed before the car is warm is around 4.5k rpm).

Hans, I like your description and sounds as if you may have hit the nail on the head. In my post weeks back I spoke about the low running temp. Even after 30mins driving, the temp readout is lucky to be 77 degrees, when 'pressing on' it can drop to around 73, and then will return to 77/78. I had the pro alloy motorsport rad fitted a few months back (plastic connector failure) and put this lower running temp down to that as thought it would be more efficient. Prior to the new rad it would constantly sit at 84/85.

I had the exact same symptoms on my 2005 111S, had the coolant sensor changed & sorted