Getting ready for the road again

[Anders Dinsen]

Thanks again, Roy, for your additional advice regarding the tank vent. I am now working on the conversion. Getting the fuel tank sender unit out so that I can drill a new hole for the valve was quite a struggle. It took a two iterations before I managed to make myself a tool that allowed me to unscrew the retaining ring. The sender unit seems to have developed a problem so I will be looking into that once I'm done with the valve. I'll be picking up an M10x1.25 nut to fit the valve in the tank and a similar sized bolt to seal off the opening where I removed the valve. The valve and the hose connected to it are both fine, so I'm just moving the valve.

The pictures today shows a particularly disgusting looking electrolytic derusting process happening today. The brown substance consists of a combination of rust, paint, and waxy rust protector as I was derusting a cover supposed to sit under the brake balance valve in fron of the right rear wheel. This cover is thin, made from 0.5 mm sheet steel. I plan to give it a coat of cold-galvanization and rust protection like I'm treating the chassis.

[Anders Dinsen]

I found the problem with the fuel tank sender which, as can be seen in the picture attached, has a broken wire some way down - or actually, near the top. The brass arm seems to have broken off causing the ends to catch the wire and break it. The sender unit is otherwise in very good condition and wire looks like 0.1 mm konstantan wire so the rheostat should be repairable if I can dismantle it without breaking anything and can find a suitable brass arm to replace the current broken one.

Roy, I've read your recommendation of the Spiyda gauge wizard, but I have not been able to find a replacement rheostat that will fit. I can only find complete in-tank units.

/Anders

[Anders Dinsen]

A few photos showing some progress while the cylinder head is with the machine shop:

• The fuel tank vent valve fitted in the better location
• The tool I made to unscrew the locking ring in the tank
• A surprised looking top part of the tank unit - derusted and pitted, ready to receive fresh paint. Yes I managed to carefully remove the connector without damaging it!
• The rear of the top fuel tank unit, also in need of some petrol resistant paint, but still fresh looking.
  

/Anders

[roy4matra]

A few photos showing some progress while the cylinder head is with the machine shop:

• A surprised looking top part of the tank unit!

/Anders

Ha ha! Yes that does look like a surprised facial expression, Anders!

And a nice simple tool for undoing the tank collar too.

A clear indication for all owners here too, note the underside of the tank sender flange has a location notch on the left in the photo, which will align the sender in the tank correctly, when refitting it, so the float arm can swing without being obstructed.

Roy

[Matraman]

Roy, I've read your recommendation of the Spiyda gauge wizard, but I have not been able to find a replacement rheostat that will fit. I can only find complete in-tank units.

/Anders
[/quote]

Anders, I struggled to find a replacement for a non-existent fuel sender, in the end Carjoy was prepared to sell me (as an existing customer) a used OEM one which works perfectly. My old fuel sender is the one photographed in Roy's tech bulletin on the topic, it was the worst he had ever seen! I tried for months with a generic unit intended for marine applications, linked to a Spiyda, but without a notch in the mounting disc the arm was always fouling the side of the tank and calibration of the Spiyda involved syphoning 50 litres of petrol out and back into the tank. Having run out of petrol for the umpteenth time I bit the bullet and paid the price for a used OEM unit from Carjoy and am delighted with it. Yours looks savable so I would recommend persevering with repairing it. BTW if anyone wants a used Spiyda please get in contact with me.

[Anders Dinsen]

Anders, I struggled to find a replacement for a non-existent fuel sender, in the end Carjoy was prepared to sell me (as an existing customer) a used OEM one which works perfectly. My old fuel sender is the one photographed in Roy's tech bulletin on the topic, it was the worst he had ever seen! I tried for months with a generic unit intended for marine applications, linked to a Spiyda, but without a notch in the mounting disc the arm was always fouling the side of the tank and calibration of the Spiyda involved syphoning 50 litres of petrol out and back into the tank. Having run out of petrol for the umpteenth time I bit the bullet and paid the price for a used OEM unit from Carjoy and am delighted with it. Yours looks savable so I would recommend persevering with repairing it. BTW if anyone wants a used Spiyda please get in contact with me.

Thanks Andrew. You're right, mine is absolutely saveable. It's actually very decent and now that I've painted the top of it black with fuel resistant engine pait it looks almost new (except that it's black and no longer gold chromated, as it appears to have been from the factory).

The rest of my fuel assembly is perfect, including the pipe and plastic filter pickup in the end. I guess I'm lucky my tank has been kept closed over the years until I removed it two years ago. I will be interested in your spiyda unit if I do not succeed rewiring the old rheostat and need to transplant a 2CV or other new rheostat onto the assembly.

I've now reinstalled the assembly without the fuel level sender with rheostat and float. It will be fine for my initial tests and running in.

I'm otherwise still waiting for the machine shop to finish their work on the cylinder head. During pressure testing they found one of the freeze plugs was leaking a little. That would have caused a problem so I've obviously asked them to replace it and retest.

While I'm waiting, I'm working on electrics under the dash. I have a good amount of cabling to route to the fuel pump relay, electrical water pump controller, and O2 sensor display. I fitted an Alpine radio with CD changer and a car alarm with immobilizer years ago both of which I have now removed, so I have to clean up what I did then. The picture shows my custom cabling being routed behind the instrument cluster.

I've also worked on the radio, which is a 1988 Blaupunkt Paris that was in the car when I bought it. I have replaced the aluminium electrolytic capacitors on the output amplifier module and installed a white LED as new backlight for the buttons. It's now ready to be installed.

And now that I had the instrument cluster out, I took out the tachometer unit to calibrate it. The picture shows it calibrated to 3000 RPM on my table with the use of a function generator and frequency counter. I've cailbrated it with similar precision at 1000 and 7000 RPM. I'm working on reverse engineering the unit, which is mechanically of quite high quality, but electronically somewhat lacking and difficult to calibrate. Information on the Philips SAA1049 IC used by Veglia is scarce, so there's a bit of thinking and analyzing needed there.

/Anders

[Anders Dinsen]

While I'm still waiting for the cylinder head to come back from the machine shop, I'm continuing my progress on electrics. I will probably have a few pictures to show after the weekend, but today I'd like to post about the backlight on the switches on the left side of the steering wheel.

They are extremely dim because they're fitted with 24V bulbs which obvioulsy emit very little light at 12V. The bulb is otherwise a normal T5 bulb of the same type fitted in the instrument cluster for which I have ordered a set of yellow LED bulbs. I'm hoping they will produce a colour which will be close to the original bulbs.

These will be too bright, however, for the button backlights, so today I tried making my own LED bulb with a standard 3 mm yellow LED and a 1K2 resistor to limit the current to 10 mA max. This is much brighter than the 24V incandencent bulb, but I think the colour matches well and personally, I think the 24V bulbs are so dim that they don't really help at all.

[Anders Dinsen]

I'd like to upgrade the illumination of the heater controls to LED, but can't figure out how to remove the buttons on the control arms. Is there a trick to do it?

Today's picture shows the difference between different illuminations of the switches. The top three are all illuminated by standard 3mm LEDs. The first has a 1K2 resistor and the next two 1K8. The bottom two switches still have the 24V incandecent bulbs. I've replaced the bulbs on all five with 3mm LEDs with 1K8 resistors and I'm quite pleased with the result.

/Anders

[Anders Dinsen]

I'm still interested in learning how to remove the buttons on the heater control arms, so if you know a trick, please enlighten me! 

Today's picture shows a prototype of a circuit I've been working on for a while: It's a detector circuit for the crank sensor pickup on the Murena 2.2 engine. The sensor is not used, only connected to the diagnostic connector, and it's a little special compared to normal sensors since it does not contain a magnet. It therefore needs to be biased with a current flow to actually detect a signal. The oscilloscope trace below shows how it triggers on a signal at about 40 mV. This test was made in my electronics lab with a random piece of iron. I'm going to working with the trigger sensisitivy on a running engine.

I'm working on this because I want to use the sensor to measure ignition advance using a dedicated microcomputer. To do so, I need a reliable trigger signal.

The bottom picture shows one of the rear shock absorbers in the derusting bucket. They are now clean and ready to be primed before being painted with in the correct Koni-red colour. I had them both restored about 10 years ago, but the paint they received back then started to come off.

[matramurena]

I'm still interested in learning how to remove the buttons on the heater control arms, so if you know a trick, please enlighten me! 

You mean the three buttons on the levers for flow and heat controll? They just pop off if you pull at them with enough force.

How does your derusting bucket work?

[roy4matra]

I'd like to upgrade the illumination of the heater controls to LED, but can't figure out how to remove the buttons on the control arms. Is there a trick to do it?

Yes if you mean the three heater control slider knobs.

You need a pick with a 'U' type bend on the end, because those slider knobs have a hole in the bottom section that goes over the end of the metal arm, and that arm has a small button sticking downwards from the underside.  So when you push the arm knob on, it sides over the button and that locks into the hole.  To get the knob off, you have to flex the bottom of the knob down off the button and then pull the knob off.  You slide the end of the pick through the slider gap so that the pointed end can be brought back into the rear of the knob to flex it down off the button.

Roy

[roy4matra]

I'm still interested in learning how to remove the buttons on the heater control arms, so if you know a trick, please enlighten me!  

You mean the three buttons on the levers for flow and heat controll? They just pop off if you pull at them with enough force.

[/quote]

NO,NO, NO.  You should never do that as it rips the bottom off the slider knob and it can never lock on again.  If you managed to get one off with out ripping it you were very lucky.

Roy

[matramurena]

Gonna get me a lotery ticket as soon as possible then since I managed to get all three of them off this way without breaking anything. And they still lock firmly in place when I place them back. (have had them off multiple times by now)

[Anders Dinsen]

How does your derusting bucket work?

It works by electrolysis. I connect a low voltage (12V) DC supply positive terminal to a piece of reasonably new, sacrificial iron. This is the anode. The more surface of the anode, the better. I'm cutting out pieces of sheet metal. The negative is connected to the subject I want to derust which becomes the cathode.

The bucket contains water with a spoonful of baking powder to ensure its lightly acidious. When the voltage is applied, a current of negatively charged electrons starts flowing from the cathode to the anode. This releases the rust, paint, and other stuff, while the anode corrodes. I usually leave it in the bucket for about 24 hours.

The subject still need to be brush cleaned with a rotating wire brush, but the result is a clean, somewhat darkened surface without corrosion. Hydrogen is produced by electrolysis, so I always do it outside.

The picture shows the anode after derusting both rear shocks.

I'd like to upgrade the illumination of the heater controls to LED, but can't figure out how to remove the buttons on the control arms. Is there a trick to do it?

Yes if you mean the three heater control slider knobs.

You need a pick with a 'U' type bend on the end, because those slider knobs have a hole in the bottom section that goes over the end of the metal arm, and that arm has a small button sticking downwards from the underside.  So when you push the arm knob on, it sides over the button and that locks into the hole.  To get the knob off, you have to flex the bottom of the knob down off the button and then pull the knob off.  You slide the end of the pick through the slider gap so that the pointed end can be brought back into the rear of the knob to flex it down off the button.

Thanks both. I'll buy myself a suitable pick and try it that way

[TELBOY]

Hi Anders, this may be of interest to you.