Got some reference info which I thought would be useful for the forum archive.
I've just got a J reg 340 which has been is storage through its MOT. Had a few things to sort out first so I thought I would post them here for future reference for people.
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Indicators
Firstly, indicators seemed to work intermittantly. Sometimes they would work and sometimes moving the stalk resulted in nothing happening. This affect both the indicator stalk and the hazard warning lights. The fuse for the indicator unit is Fuse 7 and the hazard flasher unit is fuse 13.
Both fuses were fine so it seemed to be something affecting both indicators and hazard flasher unit.
The indicator/ hazard warning circuit is controlled by a relay. On early 340s the relay is in the fuse box. Later models ( post 79 models ), it is located behind the insturment panel. There are three relays behind the instrument panel. ( Photo to follow showing the location of this relay )
On post 79 models, this relay controls the "flasher" function of both hazard warning and indicators. On pre-79 models, there are two relays, located in the fuse box.
The intermittant fault presented itself again once the instrument panel was removed and the wiring and relays accessable. Pressing the hazard switch half way down made the indicators work ( via stalk on steering column ). Fully switching the switch to fully on or off, prevented the indicators from working.
I swapped the hazard switch for a spare and the indicators and hazards functioned correctly! Looks like there was some sort of breakage or damage to the hazrd switch which caused this odd behaviour. So, if you have any problems with non working indicators, check everything as per the Haynes manual ( page 10.16 ). However, prior to replacing the relay, just check the hazrd switch isnt faultly like the one here!!
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Fuel pump problems
When 340s ( and most cars ) stand for a long time, fuel evaporates from the float chamber in the carb and eventually evaporates from fuels lines from the carb back towards the tank. The longer the car stands, the further back towards the tank is the fuel level. 340s have mechanical fuel pumps with a built in pressure regulator ( 360s have separate pressure regulators ). The pump pulls fuel from the tank, sends it to the carb and then ( this is the pressure regulator function ) excess fuel is pumped back to the tank via the narrower return pipe.
These fuel pumps are not very good at pumping air, so if a car has been standing, it can take a long long time ( need a good battery!! ) to pump the air out of the fuel lines before fuel can be pulled from the tank to the carb. A useful trick ( used this on a car that had been unused for 2 years and had just had a new engine fitted ) is to use a spare fuel pump, and to connect the cars fuel lines onto this ( only fuel pick up and return NOT the outlet for the carb ). Pumping the pump manually, allows the air to be removed faster than it would be using the battery.
However, on this occasion, in the J reg car, this trick didnt work. So instead, I connected a series of pipes made from car heater pipes to connect the vaccum line of the inlet manifold (on a second fully functioning and running 340!!) to the fuel line of the second non functioning car. The vacuum pipe used is the one which connects from the servo to the inlet manifold. The pipe is disconnected from the servo thus giving a source of vaccum. Attached to this are a series of pipes allowing the vacumm to be connected at one end and the fuel line ( inlet for fuel pump - the "from tank" line ) to be connected at the other. This vacuum effect, pulled fuel up from the tank pretty fast!!! Any fuel that enters the inlet manifold will cause the revs of the engine of the helping car to drop momentarily. At this point, disconnet the vacuum line from the fuel pump of the car you are trying to start. This now eliminates problems relating to the tank pick up and filter system. If there had not been any fuel after using this vaccum effect, one would need to look at the tank pickup.
However, reconnecting the pump to the car and to the carb, still didnt allow the car to start even though there was now fuel in the fuel pump inlet pipe. The top of the carb was dismantled and the float chamber was checked and was free and wasnt jammed and both fuel jets were clear. The problem lie in the outlet of the fuel pump. There was fuel in the inlet pipe, but nothing was coming out the outlet. Swapping the pump for a spare still didnt help!! There was fuel on the inlet side, but still nothing coming out the outlet!
Next idea was to get some fuel line piping about 30cm long and connecting these larger pipes to the fuel pump. Filling a large glass jar with some petrol and placing both the fuel pick up and the return pipe into the jar and then cranking the engine, allowed the pump to work
and fuel was pumped out the outlet. Reconnecting to the carb, and the car successfully started running on a glass jar of fuel held under the bonnet. The carb float chamber was now full as was the carb and so the fuel lines were reconnected back to the tank lines. The car now started running off the tank!!However, I have no idea why the car started running off the glass jar when it previous hadnt pumped out the outlet when connected to the cars tank fuel lines even when there was fuel in the fuel pump inlet pipe! Seems odd!!!
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Rubber fuel lines - from car fuel lines to fuel pump
One point of caution.. the short rubber fuel lines that run from the fuel pump to the permanent transparent fuel lines. These rubber fuel lines are flexed everytime the car starts and whenever the engine is running. The wobble of the engine is translated into flex of these short rubber pieces. They need to be check regularly for cracks or leaks. This constant flexing eventually weakens the pipes. This is know fault on the 340 and the RAC know to look for it on cars that wont start as crack intake pipes prevent fuel from getting to the carb!! Both fuel lines on this car were cracked and were replaced. Most car accesory shops sell fuel lines. By using fuel injection fuel lines of the correct diameter ( note: the return pipe requires a narrower internal diameter pipe ) the hoses last longer as fuel injection piping is stronger.
I hope this helps anyone who finds they cant start their 340 or has trouble with indicators.
Enjoy your 340s!
any questions, feel free to contact me shimon@volvo340.com
I thought it was all that, I've just been flattening batteries and not getting far!