Strange engine fluctuations

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Ed
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Strange engine fluctuations

Post by Ed » 06 Oct 2006 10:58 am

Hi All,

Im having a strange problem with my 1.4 340 dl cvt engine. it only happens when the outside temperature drops or gets wet. its beed fine throughout hte summer but now we have some rain and cold weather it has started playing up again.

The problem is when i first start the engine after notbeing used for a while ie: first thing in the morning or going home from work, the engine over revs it as if the switch to fix the revs has been switched on (but it hasnt) and doesnt have any real power, just makes alot of noise and doesnt really have any poke, then once the engine has warmed up the revs drop back down to normal and the car is fine. due to this strange rev issue im caning fuel.

anyone got any ideas?

thanks

Ed

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antiekeradio
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Post by antiekeradio » 06 Oct 2006 12:26 pm

carburettor and/or ignition overhaul needed.

Ed
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Post by Ed » 06 Oct 2006 02:48 pm

the carb was overhauled about a year to two years ago, there was no dirt, muck or blockages at all. the spark plugs, leads or distributor i dont think have been changed since i owned it so ill have a look at those.

thanks for your help

Ed

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5lab
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Post by 5lab » 06 Oct 2006 02:53 pm

i recon its muck inside the distro cap. try cleaning that out first and see what happens
Siddy-'87 360 Glt lhd convertible
Swapsea-'89 360GLT-swapped!
Leah-'84 340GL-sold! Maisie-'85 340GL-sold!
Snowy-'88 360GLE-killed by a truck! Dougle-'89 360GLT-dead&stolen!
Nessy-'86 340GL-foggy's! Grace-'86 360GLT-gone!

Ed
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Post by Ed » 06 Oct 2006 05:41 pm

being that this is a cvt, could it be to do with any of the vacumns on the cvt?

it just seems very odd that it only does it in the rain or cold

Ed
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Post by Ed » 06 Oct 2006 05:58 pm

also there is a switch next to the automatic gear select, what is this called? and where does it connect to? as the engine acts as if this is switched on but it isnt?

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petefarrell360
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Post by petefarrell360 » 06 Oct 2006 06:11 pm

That's the low gear hold switch, which selects a lower gear for coasting down hills etc, not to be used at high speeds. I'd start with the distributor cap and leads as Hugh suggests, mainly because I can't see how the damp can affect it if it's a vacuum or switch, and then the warmth sort it out. Could of course be wrong!

Where abouts are you, as Mac has a CVT tester he has developed. My CVT should be on the road soon for him to check against a supposedly working car, then maybe he might not mind testing yours, worth asking him. I'd try the other routes first.

Pete
G reg 360 GLT, G reg 340 GL Variomatic, plus many more..........

Ed
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Post by Ed » 06 Oct 2006 06:13 pm

im in the south of the uk, basingstoke to be precise

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antiekeradio
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Post by antiekeradio » 06 Oct 2006 06:14 pm

OWWW...... thát problem... new diagnosis ->


its well possible that the 'tacho relay' has a broken soldering inside.

this is a known problem and can be fixed by opening up the tacho relay and resoldering the relay connections on the printed circuit board.

the weight of the relay is only supported by its electrical connections, which causes these to be stressed quite severely. liberal use of solder prevents the problem occuring again.




PS "the switch to fix the revs" is called the "low gear ratio hold switch" (or, translated literally from dutch; hill brake switch)

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Chris_C
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Post by Chris_C » 06 Oct 2006 06:15 pm

I'm in Soton, and have lived with a 1.4 for several years, so if I can lend a hand etc?

tbh, I'd say you need a new arm/leads/cap, as they are pretty known for being eaten. Spend the extra and get volvo ones from a dealer, they last a good couple of times longer than factors/halfords ones.
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antiekeradio
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Post by antiekeradio » 06 Oct 2006 06:25 pm

changing the cap/leads is a service item and needs to be done once in a while to guarantee a smooth-running engine.

Ed
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Post by Ed » 06 Oct 2006 06:28 pm

if it was down to leads and distro, why would it only be affecting it in the wet and cold and not all season? and it did it exactly the same last year in the same weather

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antiekeradio
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Post by antiekeradio » 06 Oct 2006 06:35 pm

air is a better insulant than mirky water.


this means that the spark gets to the combustion chamber when dry, but escapes through somewhere else when wet.

new plugs, new wires, new distributor cap and new rotor, will make sure that the spark gets to the combustion chamber, even when its pooring down like a :evil:

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Carl
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Re: Strange engine fluctuations

Post by Carl » 06 Oct 2006 06:55 pm

The damp will cause havoc with knackered/old ignition systems. For any car with running problems the best bet is definately make sure the plugs, leads, cap, rotor arm and coil are in good working order. If you're not sure when they were last changed then change them!

Also a bit of carb cleaner cant hurt to make sure it's nice and clean too. I used to have to do this every month to the Solex on my old 205 otherwise it would run like a pig!
Carl
Rover SD1 Vitesse (and no Volvos :()
But previously:
1988 Volvo 360GLT
1988 Volvo 360GLT
1984 Volvo 340DL
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Ed
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Post by Ed » 11 Oct 2006 05:45 pm

further to my question,

spoken to a Volvo mechanic who suggested that the clutch is slipping. Im still not convinced this is it as why would it only slip in autumn time and not the summer!

Im still convinced that is has something to do with this 'low gear ratio switch' as the revs fix at a certain pitch and the car doesnt seem to be able to go any quicker untill the revs drop, the car acts as if this switch has come on. Does anyone know

A: where does this switch connect to?

B: Is it fused?

C: Can it be disconnected for elimination process

thanks for any help

Ed

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