Calm down, calm down!

[Tom]

Quite.

[jtbo]

Update - all is well again!

Well, almost. The car performed without issue this morning on my way to work, but the high-revving symptoms briefly resurfaced on the return journey. However, they soon disappeared, and I've just taken it out for a run now and it's again performed without issue.

I'm utterly confused. I can't help but think of it all as a harbinger.

(Sorry about the persistent updates to this thread - at least if anybody else has the same issues, they'll learn the square root of fuck all from it. )

I would imagine that because issue were fixed by installing some hoses, it would be good idea to follow those hoses from all the way they go and check if there are any cracks.

I had some cracks in hose that goes from valve cover to EMV, it goes around the carburettor, so that to see it properly one need to remove air filter box from top of the carb, then it is easy to chekck all the hoses that there are no cracks.

Other thing I found with my vario was that smallest wire connector to EMV (under rubber shield) was bit loose, I had to use pliers to tighten that connector so that it made reliable contact to gearup side of EMV.

After those I would check that brake pressure switch or accelerator pedal switches are not sticking as it would cause high rpm conditions again, at least that is my understanding.

CVT diagnostic manual, if you search that in here, you should find post that describes all steps in more detail and in correct manner, which I'm afraid I can't explain so well, vario stuff is still bit new to me.

[Tom]

jtbo, many thanks for your extremely helpful reply, I'm going to go out now and take a look at the carb area.

[Tom]

Well.

I've checked both the vacuum system parts under the car and the EMV itself in accordance with the CVT diagnostic manual, but I've stopped short of checking the electrics as I don't own a multimeter. I did however make sure everything was securely plugged into position.

Anyway, the pessimist in me thinks it's a case of 'something's buggered' as opposed to 'something needs adjusting'. The car has developed a new habit now.
It'll drive fine for the first fifteen minutes or so, but then starts doing the high rev thing (even minimum application of power sends the revs straight up to 30, even more so at speeds of higher than 35mph). Even during these phases the engine does momentarily sit at the correct revs sometimes, but will invariably climb up to 30 even if you keep the accelerator in the same position. I've even phoned the Volvo guy I got it off and he reckons it might be the EMV, but as I've checked that, I'm pretty sure it's not. I'm completely and utterly stumped.

[jtbo]

As it takes time, I would guess that there must be vacuum leak that is caused by heat expanding, I would start examining if between intake and carb bottom there is a leak then.

One thing that puzzles me however is that this should happen also when it is in neutral too.

I recommend to buy a multimeter, it is very useful for many things, some, even rather low price units have even temperature metering bit, you never know when you need to measure a temperature of something

I guess you can find enough good ones for around a tenner or so?

[macplaxton]

I guess you can find enough good ones for around a tenner or so?

"The shop with big windows" (so they can see you coming) (a.k.a. Maplin) does one for £6.99.

An equivalent one (wait ages for the postie to deliver) one from China on fleabay is a mere £2.64 including postage. It would be rude not to have one: http://www.ebay.co.uk/itm/200459570494

[Chris_C]

FWIW, one of those five quid multimeters is only 0.05V off from my £800 Agilent at work when it's got a good battery. For car work, they are awesome. Anything more than reading volts or resistance you have to take with a pinch of salt, but again when do you ever need that on a car!

The accuracy drops off horrendously on an old battery though, which is where I see the difference between a good and a bad meter.

[Tom]

Hi again chaps.

I apologise for appearing to ignore your advice, but as I'm not totally confident with anything under the bonnet I decided to just take it back to the garage, who spent a couple of hours with it and are pretty certain it's the EMV that's playing up.

He admitted that he wasn't sure how he was going to get one and reckoned I'd have a job on finding one too. So I thought it might be worth it to ask on here if anyone has one lying about? I'm tempted to make a seperate topic about it.

Again, sorry for appearing to be rude by ignoring folks' advice, but I thought it'd just be better to hand it over to someone who actually has a clue what they're doing.

[jtbo]

Hi again chaps.

I apologise for appearing to ignore your advice, but as I'm not totally confident with anything under the bonnet I decided to just take it back to the garage, who spent a couple of hours with it and are pretty certain it's the EMV that's playing up.

He admitted that he wasn't sure how he was going to get one and reckoned I'd have a job on finding one too. So I thought it might be worth it to ask on here if anyone has one lying about? I'm tempted to make a seperate topic about it.

Again, sorry for appearing to be rude by ignoring folks' advice, but I thought it'd just be better to hand it over to someone who actually has a clue what they're doing.

That is not rude at all, better safe than sorry they say

[Tom]

'Ow do, chaps and chapettes. Hope everyone's fine and dandy. Thought I'd update this thread!

The car is still playing up. It's the same problem but in reverse now - the car SOMETIMES rides along at the correct revs (although increasingly rarely, and for short periods only), but in the main it's revving it's nuts off. Just over 3,000rpm at 30/35mph and quite a bit higher for anything over that. It's driving me potty.

I've had the EMV overhauled using the kit provided by the kind Maxplaxton and volvodspec of this parish, but unfortunately it hasn't made any difference. The mechanic assures me he followed the instructions to the letter.
As a temporary solution I've tried disconnecting the green/yellow wires on the EMV as per volvodspec's instructions in another thread on this forum, but again, it's made no difference.

Will the low gear hold switch not working have any effect on the revs? I don't think it ever has worked. I remember driving the car not long after I bought it and seeing the switch was illuminated but the car seemed to be driving perfectly normally, which led me to just assume that it was knackered. This didn't bother me at the time as I knew I wouldn't be towing a caravan or driving in mountainous terrain any time soon.

I've managed to borrow a multimeter off a mate, so I'm going to test the electrical system as per the CVT manual at the weekend. Sorry for the long post, and thanks in advance for your replies/patience.
Tom