Idle speed erratic / going topless
 

Hey all

Well, it's been a long porscheless winter here, when the car went out of action in November, it was a crazy busy time for me so I just parked it up on the drive and left it for a few months (Yes, I now know it's not a good idea, especially during a UK winter).

So anyway I get the car collected and my local guy looks at it, tells me the fuel pump was what the problem was (a mild good feeling as that's what I diagnosed when it happened), anyway lah-de-dah £XXX later the car is running again.

So, here are my remaining problems;

- The engine is idling 'all over the place'. It's anywhere from 900-1200 a couple of seconds somewhere in-between, then up for a few seconds, stutter a tiny bit, down, up etc. It's acting like the petrol isn't good petrol....if that makes sense? Or something.....
Anyhow today I used the good weather to follow one of Pedros guides, I took apart the throttle components, and cleaned them up (not as easy as Pedro makes out ;) and I would definitely reccomend having a magneteic tool thing as he says :D ). There were some slight deposits in the throttle valve, and a slight amount of coke/carbon/whatever in other places. But considering it's done 102k miles, I was expecting worse.
I was going to take the MAF sensor out but realised you need security star-shaped things to get it off, I didn't have any, so it'll have to wait.
Anyhow the cleaning didn't alter the random idle speed at all, even after warming it up with a drive. It might just be psycho-sematic (don't quote me on the spelling) but the car seemed to have more life in it then pre-cleaning the throttle components.
So, now I'm a bit stuck. I used to have a BMW330i, and on that over 2 years, the pre-cat, post-cat, oil temp, crank-shaft, and crack speed sensors all went which all affected the drive. I don't know where to start on the Boxster....the MAF seems easiest :rolleyes:

- And then my second problem. Before I abandoned the car for the winter (i.e. before I started my own mould farm), the roof got stuck. I had to disconnect everything and it's been a manual effort ever since.
I've checked the switch which lies at the back of the soft-top, a lever like affair, seems ok. The switch in the dash is ok too. Now seeing as there are two motors (I am correct in that I assume?) I'm assuming one would work whilst one didn't, fi one had died.
The relays are all fine, the fuses are all fine.......

Any ideas on the above?

Thanks!!

:confused:

I can't help you on the roof problem, I've never encountered it myself and I'm not the best mechanical mind around.

My advice on the idle is go plug it into an OBD-II and see if an error code comes up. I once tried to self diagnose an "MAF sensor" problem, replaced the part and it turned out to be oxygen sensors. Had to replace those too and it became an expensive exercise for no reason. In retrospect it is a good thing to have all the main sensors replaced.

Both MAFS and oxygen sensors tend to be bigger problems and will most always result in a CEL on the dash. Other things such as air intake temperature sensors (which may or may not be built into MAFS, don't quote me) tend to cause relatively small problems like what you are describing. Either way, OBD-II is the best solution to avoid wasting time and money playing guessing games.

I've had erratic idle speeds for a long time now, it developed into first the car stalling rarely on idle when turning on full lock, then it started stalling every time it reached idle RPM's. It turned out to be a bad MAF, but really it could be anything like Oxygen Sensors.
I agree with running it through a OBD II, it may throw both O2 Sensors and MAF's even if its just one failing. They are linked so one bad part might cause the others to not function properly, thus the codes.

Thanks guys. I did actually connect my ODB scanner/reader up to the car, and it didn't find any codes. I'll take the plunge and order a new MAF sensor, see if that makes any difference.

I now have another problem.....will post a new post as it's unrelated. :ah:

There is only one electric motor that drives both top transmissions. It's located directly under the "lever-like affair".

Here is a link that should help you resolve any of your convertible top problems:
http://sites.google.com/site/mikefocke2/thetop-itsmaintaince%26replacement

Regards, Maurice.

Thanks Shoir, will take a look!
I wonder if it's possible to send a live feed directly to that motor then.....that way I'd know for sure whether it had died or not.

Update on the idling speed problem. I bought a new MAF sensor, switched it for the old one...

(which, incidentally, was so clean it looked new, I almost didn't swap it out, thinking I would send the one I bought back for a refund).

...anyhow I thought what the hell, I'll put it in anyway. So I get the old one out - the hex security bolts were fairly rusty, I had to use pliers to get them out and then could only use one of the originals when fitting the new unit, and had to carefully choose a perfectly sized screw to put the new one in.

Started it up (after dropping my socket set on the floor and seeing all my sockets disappear under various shelves and into boxes :rolleyes: ) and....

It idles much better now! :cheers: I think it drives better too, but that might be psycho-sematic (don't check my spelling) as my other cars are slow beasts.

Now I just have to fix;
1) the roof (which I suspect is the centre windscreen latch/switch assembley).
2) work out why I can't lock my car, it unlocks it again for me and beeps twice (???)
3) Check whether the white smoke on startup is the AOS, or something worse.

I don't think I'm going to be ready for the European Road trip we have planned for June at this rate, might have to take the MR2 again.......