Hi anyone know what the black box next to the wiper motor does? According to Volvo its an ignition control Relay, but what the hell does it do?
Cheers Adam

I think it's a fuel cut out controller for the Solex carb. Solex carb acts quite like an injection system above the certain rpm level, as it cuts out the fuel during the engine braking like the injection does and by doing this it saves fuel.

I might be wrong though, but if someone has better knowledge, please tell.

MAC !!!!!!!!!!!!!!!!!!!!!!!
one for you I think , although I know your not around much at the moment

In the absence of Mac......

If its the thing that has 209472 stamped on it, its the fuel cut off relay for the Weber carb. It has 2 inputs, RPM and throttle switch. Normally, it outputs 12V to the fuel cut-off valve in the carb when the ignition is on, except under the following condition......RPMs about 1400ish and throttle closed. It then shuts off the 12V to the fuel cut-off to increase fuel economy.

The B200 has it too, for its carb, but strangely enough the 1.7 doesn't

You sure Andy? I know Kar has one, but I thought Fake did too... Always wondered what that box it too!

hi guys

yep, that box is the solenoid idle valve controller. shuts off fuel during whats called overrun condition ie throttle fully closed but revs above 1000. for the 1.4, the solenoids shuts off when the revs are above 1700...i'll need to check the green books to know the revs but from memory its 1700..... maybe less

Im thinking the main fuel jets arent working when throttle closed just like they dont at idle with the throttle closed to solenoid cut off is effectively full fuel cut off. the B14 4S had a similar adaptation for sweden for ovverun conditions to meet swedish emission regs

S

Cheers Guys
Adam

No probs mate:)

The B14.4s had a different arrangement on the carb. It was a vacuum diaphragm attached to the throttle lever, which, under certain conditions would lift the throttle and raise the revs, possibly to try and reduce the NOx emissions on over-run....

Hello,

I searched for the declaration for this box, too and found it here.
But where is the fuel cut-off valve in the Weber Carb on 1.4l engine?
I only know the electrical idle jet.

But I will tell you a problem I have with my 340 1,4 Variomatic. It can be that the problem based on this box:
If I start the car an drive e.g. 500meters the engine sometimes stops. The clutch is still closed then and the engine is driven by the wheels.
If I pull the gas pedal the engine doesn't work on. When the stands still and I start the engine normally it starts working in the normal way.

What can this be?

Best regards Matthias

variomaticus_dl wrote:I searched for the declaration for this box, too and found it here.
But where is the fuel cut-off valve in the Weber Carb on 1.4l engine?
I only know the electrical idle jet.

Yes, it is connected to that. When throttle is zero AND engine speed is greater than 1600rpm, the idle jet will be switched off to save fuel. There may well be a slight delay on it (or connected to the braking) so it doesn't affect changing up through the gears. It only appears on later cars from around MY87 onwards.

thanks for your explanations.
After studying the green book I've found the chapter

What do you mean? - Consequently this function could be removed, I think.
The reason: in my other 340 from 1989 there is no such function and it runs perfectly...

The electrical idle jet is simply turned by 12V.

Best regards Matthias

...and I don't understand the real sence of this function...

variomaticus_dl wrote:The reason: in my other 340 from 1989 there is no such function and it runs perfectly...

Should be there, unless someone has taken it off ??

It's there for fuel economy.

HI again,

after repairing the soldering joints of the "black box of mystery" my engine-running problems are cured
The same procedure as with the vacuum valve.

Thanks for your help!

Best regards M.

Did you manage to get any photos Matthias?

I'd be interested to see the failure, wouldn't surprise me if a few cars have it!