hi i have a 340 GL cvt 1990, but it seems to be revving realy high 30mph @ 3000revs,
i have disconnected the overdrive and now the low gear hold works properly ie when the switch is pressed on the revs go higher, but still cant get the revs down, could this be a vaccum problem from the manifold, or is it the dreaded tachometric.
any ideas very welcome.
thanks.

take a look at the EMV, disconnect the thinner hose that goes to the gearbox and hold your finger against the EMV side. now increase the revs to above 1800rpm, this connection should suck noticable by your finger.

if it is not sucking, get a multimeter and hook it parralel to the green and grey wire, again increase above 1800rpm:
if you get aprox 12V- the electrics are fine and the fault is in the EMV, unscrew it and theck the rubber valve, this might be broken.
if you don't get 12V- the problem is electric, unscrew the EMV and de-solder the diode at one end, now do a resistance check on the coil (should be around 35Ω) and check the diode for blocking in one way. if both of those are fine the tachometric relay has a blown the end-transistor

if you get vacuum at the thin hose, remove the thick hose behind the EMV and blow (no compressed air!) on the thin hose that goes to the gearbox, "fill" it up and see if you can hold it up to pressure by releasing the air after aprox 10 seconds. if that happens; gearbox is fine; other possibilitys:

if the air you blow in the thin hose, it comes straight out of the thick hose. in that case a menbrame has ripped.
if the air you blow in the thin hose, get it to pressure but after 10sec there's no air blowing back out of the hose, the gearbox has a vacuumleak at the flexible seals

Another thought: Slack belts will not do the gearing any favours and send revs up.

many thanks for that, i shall test it tonight and let you know.
Lewy
oh where is the transistor? is it in with the tachometric.

lewy wrote:oh where is the transistor? is it in with the tachometric.

Yes, it's inside the black box. THIS PAGE might help you if you need to go there, but check the more easy/obvious things first

ok thanks for the info on tachometric box showing the transister, that wes great.
today i have done the tests on the EMV and all seems fine so it must be the black box, so took the tachometric box of the 340 and did a test drive the revs were 3000 @ 30mph, fitted the box back on did a test drive the revs are the same 3000 @ 30mph.
the black box has now gone to have its transister changed.
crossed fingers this will be it!.

Can anyone tell me what revs i should have at 30mph,
got the end transister replaced seems to be slightly better now, but the revs still seem to high! how tight should the belts be on the pullys, as i have looked at them and they do pull down about 20mm,
any more ideas on this please.
lewy
confused
and
getting sad.

Can't answer the revs question as my poverty spec car doesn't have a tacho.

Gap between rear pulleys is 1.5mm - 2.0mm. That's right at the bottom of the V formed by the pulley halves. Don't guess. MEASURE.

As a guide to the stage where the belts are at, the width of belt at widest point when new = ~45-46mm. Width of belt when near the end of the available adjustment ~38mm.

volvodspec wrote:take a look at the EMV, disconnect the thinner hose that goes to the gearbox and hold your finger against the EMV side. now increase the revs to above 1800rpm, this connection should suck noticable by your finger.

if it is not sucking, get a multimeter and hook it parralel to the green and grey wire, again increase above 1800rpm:
if you get aprox 12V- the electrics are fine and the fault is in the EMV, unscrew it and theck the rubber valve, this might be broken.
if you don't get 12V- the problem is electric, unscrew the EMV and de-solder the diode at one end, now do a resistance check on the coil (should be around 35Ω) and check the diode for blocking in one way. if both of those are fine the tachometric relay has a blown the end-transistor

if you get vacuum at the thin hose, remove the thick hose behind the EMV and blow (no compressed air!) on the thin hose that goes to the gearbox, "fill" it up and see if you can hold it up to pressure by releasing the air after aprox 10 seconds. if that happens; gearbox is fine; other possibilitys:

if the air you blow in the thin hose, it comes straight out of the thick hose. in that case a menbrame has ripped.
if the air you blow in the thin hose, get it to pressure but after 10sec there's no air blowing back out of the hose, the gearbox has a vacuumleak at the flexible seals

with the thinner hose dissconnected and revs increased to 1800+ theres no sucking?
also dont get any current to the green/grey wires with revs increased to 1800+ current constantly remains at the other 2 wires on the other side?
when checking the wires into the micro switch as per green book guide .... when i test the red wire next to no8 wire (with circit tester) the valve clicks and i then get current to green/grey wire side of the valve and the valve operates,,,

so i temp earthed this wire to keep current to the green/grey wires and test drove it (no difference?) .... would i be right in thinking that the microswitch/relay thingy has failed?

lol sorry posted in wrong thread :S

macplaxton wrote:Can't answer the revs question as my poverty spec car doesn't have a tacho.

Gap between rear pulleys is 1.5mm - 2.0mm. That's right at the bottom of the V formed by the pulley halves. Don't guess. MEASURE.

As a guide to the stage where the belts are at, the width of belt at widest point when new = ~45-46mm. Width of belt when near the end of the available adjustment ~38mm.

ok found that the two rubber diaphrams have split in the EMV, so need to replace them, any idea how to get hold of them.
thanks for the info on belts, will check belts this week end.

lewy wrote:ok found that the two rubber diaphrams have split in the EMV, so need to replace them, any idea how to get hold of them.
thanks for the info on belts, will check belts this week end.

The rubbery bits inside this:


Can be had a as a repair kit. I'll be back in a mo.

No got a picture here of the repair kit, may have one later.

can i get the kit in the UK, as i cannot find one on the internet.
is there a link to a web page.

I got some UK stock of the kits £18 posted. As I'm not in the UK, I have get my man that can to do the pics for me of maybe "vermillion" on here can tell you more. He supplies the kits. Search here under "emvk".

Still at work, and can't do much on this phone.

The kit I think he has is the Born Built Beauties overhaul kit for the EMV.
Those can be worth waiting for, just do a search in Google for them (Born Built Beauties and EMVK).




These are probably the parts you are looking for.

There is also a pirated copy of this kit around.