Tyringe

The last few days my S2k has been stuttering and kangerooing far more than it has ever done to the point where it is getting annoying.

Previously I thought that I had learnt to avoid but now...

Anyone else noticed this recently with the onset of the cold weather?

I started using Optimax three tank-fulls ago - not sure how that might affect - would have thought it would have made it better?

Did anyone ever come up with a resolution for this?

Cheers,

Keith

Tyringe

(Keith replying to his own thread!)

Well, after doing the searches here, the consensus seems to be the MAP sensor.

Another 30 mins searching and not finding a picture of it, I went outside to look and, yes, everyone said it is easy to find and it is.

I'll wack it with a screwdriver (that's the recommendation! Tried my hand and just got a bruised knuckle) tonight and see if it fixes the problem.

Keith

Tonky

Being as you've recently changed your fuel don't forget that it's a learning management system as well, which adjusts to all sorts of things like changes in fuel. It can take a few miles/ fill ups to adjust.

Tyringe

Is three tanks recent?

Is there evidence for the "learning" system? I've heard it said but wasn't sure if anybody had any hard facts.

Interesting to think that it may adapt to these kinds of things.

My old Rover Coupe always used to drive like a dream after I'd been away for a week on business and my girlfriend driving it in the meantime, but I put that down to fluke.

Keith

Tonky

I would have thought 3 tanks would be enough but others who've made fuel changes will no doubt be posting Again the more technically minded, Brian, Red will advise I'm sure on the learining system but I feel safe in saying, yes it adapts to the way you dirive, how often you vtec, where your gear changes come, all sorts of things. Another little known fact is that your dealer can put the car on a diagnosis machine and tell you how it's been driven, when you last vtec'ds etc. More than one owner has been caught telling porky's!

AnDy_PaNdY

Turtle

Can you be more specific as to what circumstances you've had this reluctance/kangarooing?

I've had two different forms.

Firstly my car used to sometimes not picking up cleanly from low revs. It would start picking, hestitate and then go pickup. Made slow speed progress a pain. A blip of the throttle, or using a few more revs when setting off helped. This hasn't happened since I switch to Iridium spark plugs - which seem to make the engine happier to pickup from low revs primarily.

Secondly, I've had a problem only once so far. This occured when the car was hot after a long drive, and was then stuck in stop go traffic. (On the A5 heading to the dealers to have a problem sorted as it happens....). This time, the car would pickup and then die a little, while moving without my changing throttle level. This was very disturbing - could have put me into the back of a car, in that kind of traffic. This hasn't recurred thankfully, and may have been due to another problem on the car that has since been fixed.

As far as the ECU goes, simply put it has long and short term fuel trim and other parameters. If you're not running WOT (full throttle) and are below Vtec, the ECU uses the map sensor, O2 sensor etc, and adjusts the short term fuel trim, ignition timing etc as required. Over time short term changes are corrected into the long term map - the idea being that generally short term trim should be near zero, signifying that the ECU has 'learnt' the conditions. I can't remember exactly how long it takes, but it shouldn't be causing problems - I've recently switched to Optimax with no problems.

I don't think this is ECU related, however if you want to eliminate it, it is easy to do a ECU reset to force it to start adapting from the factory maps again. This is covered in the faqs - it's a simple case of pulling a fuse for 10 seconds. Then give the car a few days (I think it's related to starts, rather than time though) and see what happens.

If you still have problems, take it to the dealer, go for a little run and demonstrate. From the sounds of it you can nearly do it on que. You could mention that there have been other owners with map sensor problems causing this. I think it's a much better idea to drive a mechanic yourself, rather than just leaving the car, since they're unlikely to be familiar with the way the S2000 picks up normally.

Please keep everyone up to date with how you get on, and good luck.

-Brian.

Turtle

Some people even have access to a friend with the required cable and software to hook a laptop up.

-Brian.

Tyringe

Thanks for the info Brian.

The problem has only really got very bad in the last couple of days.

It happens when accelerating, at low speeds, and when cold.

I have removed the MAP sensor this evening but there isnt much you can do to it as it is sealed. I gave it a couple of taps and I'm just gonna go out now to see how it is.

Keith

Ross

Keith,

Please let us know how you get on, I too have a similar problem and have also recently switched to Optimax, would be interested in your results.