V340 Vario blowing vario controller

[pyoorkate]

Hiya folks,

Just wondering if anyone has any suggestions for this problem; we're currently without a garage* so our local Volvo specialist has been trying to solve it, but so far without luck.

We've got a standard 1989 Volvo 340 Vario, and a few weeks back it blew the electronic controller for the vario (meaning the car was stuck in low-ish ratio - equivalent maybe to up to second gear).

It took them two visits, but they found that the Vario control box had shorted out and died, they replaced it, but a few days of use and the problem's resurfaced, so I'm suspecting that it's died again. The car's going to go back to them but before this goes from painfully expensive (it's already cost the car's value) to ridiculously expensive, is this a problem anyone's encountered before? Is there anything that we should maybe remind them to check - I don't think they see a lot of varios...

Apart from this, the car's fairly reasonable (bit of rust here and there, but remarkably solid for an everyday car) and I love the vario driving experience - so we'd be loathe to get rid of it, but our finances aren't exactly bottomless!


* Although I suspect this is beyond my knowledge of varios anyhow.

[morgan105]

Has the low hold switch been knocked on by accident on the centre console? Ours occasionally gets knocked on by the kids or wife hitting it by mistake thinking she is putting the rear wiper on without looking and forgets to turn it off if she has done this. Worth a look.

[pyoorkate]

Sadly not, that was something both my partner and I optimistically checked! :/

[macplaxton]

Sorry to hear about the current woes with Chester, Kate.

Now which bit exactly has gone wrong: The 4 way vacuum valve or the tachometric relay?

You're a dab hand with a soldering iron, are you not? Should be beyond you to fix it.

There's also a scanned CVT Volvo service manual green book in the technical resources section (clicky) and a good thread HERE to look at.

[pyoorkate]

Yeah, he's been an excellent car, but it looks like the rapid accumulation of miles (my mum lives in Cornwall) is finally catching up with us.

It's the tachometric relay that failed last time - and has I suspect failed more or less immediately on replacement. If it's a user-servicable part (when the user is me), then I'll make sure they give me the old one when/if they change it this time. Problem is we *really* need the car; my partner's job is only 12 miles away, but it's 12 un-publictransportable miles (seriously, you actually have to leave the night before to get there by 8:30am, and it's only the other side of Bristol!).

Anyway, it goes in to the garage tomorrow, if they can't fix it, apparently Volvo Bristol has now changed back into being a real Volvo garage, and they know a 343 - so it might have to go there :-/

In a few weeks our driveway becomes a garage*, at which point I'll be able to do some work on things again!



* Whilst working on cars on a driveway isn't something I am totally averse to, at the moment all my tools are in a storage locker several miles away. Thus working on the car is an impossibility.

[theo2468]

Where abouts in cornwall, I'm in st Ives if you know where that is

[pyoorkate]

We're actually in Bristol, it's the trips down to my mum's near Liskeard on top of my partners daily commute...

[macplaxton]

It's the tachometric relay that failed last time - and has I suspect failed more or less immediately on replacement. If it's a user-servicable part (when the user is me), then I'll make sure they give me the old one when/if they change it this time.

Make sure you do. It's not really meant to be user-serviceable, but they can be fixed up, so don't chuck.

Now you say this is the second one to go south? I'm not a 100% on this, but if the diode in the 4 way vacuum valve is dud, it can toast the tachorelay. However you can cover yourself by fitting a diode to the tachorelay when you're in there fixing the transistor, so even if the 4 way vacuum valve one is dud, it won't kill it.

Diode looks like a bog-standard 1N4001 or similar rectifier job.

Have a quick butchers at this Google-mangled page of Wouter's HERE

If you're really stuck, I hear Howard (also in Bristle) might be selling a DAF...

[Chris_C]

At work, so just a quick aside to help in the UK remaking of these things.

Maplins don't list a BC337 (they likely have an equiv though I havn't time to check atm, don't use a BC547 or similar as it doesn't have the current switching abilities) but RS show them for 10p ea

http://uk.rs-online.com/web/search/sear ... &R=6254966

[Speedy88]

Goddamn, if I even knew the first thing about varios I'd be over to help you in a flash. I'd just be another head scratcher though, sorry

[volvodspec]

naa, i don't believe you can blow up the tachometric relay twice in a row. becides if the transistor and diode blow the car won't change up wich feels quite different to the monster rpm low gear if that's stuck.

what kind of driving effect do you have, are the revs slightly higher as usual or extremely high; just like when you have the low hold switch on??

start the engine and bring it up to running temp. pull the 2 hoses off the EMV that go to the gearbox (note the bigger and smaller hose; make sure you connect them the same way back later!); neither of the connections on the EMV are allowed to suck at this moment. if the connection where the bigger hose was on sucks, pull one of the wires off the coil to see if it stop's sucking.

if it stops hook a multimeter to these wires and select the Volts setting so you can start searching. note the 2 wires that go to the pressure sender on the brake master cylinder; interconnect these 2 wires with a piece of thread and test to see if you get 0V again. if you still have 12V on the kickdown-coil; go inside to the gaspedal. search for the yellow/green wire and connect it to ground and check if you get 0V

if it still sucks when you pull the wire off, the valve inside the EMV is broken, unbolt the thing and screw it apart to check it. mr Volvomania on here sells rebuilding kits with brandnew valves http://www.volvo300mania.com/forum-uk/v ... 44#p136344

if this is all OK, rev the engine up above 1800rpm and feel with your thumb if the gear-up (smaller hose on the EMV) is sucking, this is a restricted vacuumfeed so you won't hear it like the kickdown side

[macplaxton]

Maplins don't list a BC337

Now why would they? They've got flashing disco lights to stock.

Anyway, there are plenty on Fleabay cheap without leaving the house. Trouble is you may want to find another 9 tachorelays to fix!

naa, i don't believe you can blow up the tachometric relay twice in a row.

^^^^take note of what Dr Vario den Akker says

There's a load of simple tests that can be done on the driveway.

1) Vaccum tests
2) Electrical tests
3) Vacuum tests

btw, if you do need a 4 way vacuum valve overhaul kit, I have UK stock.

and if in doubt, check the vaccum side of things again...

[pyoorkate]

what kind of driving effect do you have, are the revs slightly higher as usual or extremely high; just like when you have the low hold switch on??

It is like having the low hold switch on. 30mph is thrashing the poor benighted thing.

It's back at the garage early tomorrow, but if they don't/can't fix it I'll run through the tests. Thank you very much for that info, it's always useful to have more fault finding tips. Unfortunately we live on a rather steeply inclined narrow road, so until the garage (and tools) are sorted it's a bit difficult to do much.

[morgan105]

What are the revs like when wanting to start off? Clutch gap or pulley gap on belts may be wrong. No gap on the pulleys would mean slack belts giving no top end speed. To big a gap on the clutch would not bite early enough also resulting in higher revs before movement.

[pyoorkate]

Hiya,

Thanks for the input guys - the garage report that the tacheometric relay contained a faulty soldered joint. Having resoldered it the car is currently driving fine.

As a side point, they didn't attempt to charge for the re-repair (restoring some faith in them). We'll see how it goes

--
Kate WE