1984 conundrum

[DoubleOSeven]

Experienced a loss of power at 2500rpm, very intermittent initially. Now I have loss of power under load, a back fire on occasion. I’ve been through the fuel system, it’s fine. I did witness a spike on the Rev counter the other day, with the revs noticeably ‘not’ changing. My thoughts were the coil is going bad. Here are my green coil figures and a ‘new’ coil marked 043905115/C I have from VW Heritage (Brickwerks sold out). Ah, this Bosch is no good, no pins, must be for early DIN type.

Is my coil bad?

Also the rotor arm and dizzy, well; these look like they need a change don’t they, I’ll get that done.

Oh, checked the timing. It’s ok.

Haynes figures, coil doesn’t look a million miles out, but that Bosch one is way out of spec.


Stuck the rotor tip on the wire wheel and tried to clean the distributor points to remove carbon. Re-fitted, but fail. Rev counter very sketchy now, bouncing quite a bit. Definitely need replacing.

Could borrow a coil off the Mk2 Golf, similar spec.

[DoubleOSeven]

HT lead #4 was open circuit. Problem solved.

Brickwerks HT leads, out of stock. The Mk2 will have to wait it’s turn, ie I robbed a HT lead off it

Ah, satisfaction. It’s a nice feeling. Back on the road.

[bigherb]

That coil is for points ignition systems.

[DoubleOSeven]

Not solved. Hesitating and trying to stall @ 2500rpm. After some more reading on this forum I believe I have an issue with the 2nd choke pull down unit.

VW PART NO 025 129 061

[DoubleOSeven]

Early van wiring question. Where does this connect to please?

[Mocki]

That’s all wrong .... those black wire all inter joined are for the choke and carb and fuel cut off , the inlet manifold heater should be connected to that thermo switch . I don’t have pictures to hand , but all the c
Blacks take power from the ignition live to the coil and are always live when the ignition is on, the manifold heater takes it power from the relay in the black box switched via that inline thermo switch and only powers up until the coolant is up to switch off temp

[DoubleOSeven]

Thank you, I’ll go sort that all out.

[DoubleOSeven]

Can you clarify...

Thermo Switch feeds:
1 x carb. base, little heater
1 x carb. autochoke
1 x Hedgehog manifold heater

12V permanent feed:
1 x carb. solenoid for the fuel cut off

Am I close?

[937carrera]

These may help

https://club8090.co.uk/forum/viewtopic.php?f=37&t=151139

https://forum.club8090.co.uk/viewtopic. ... 1&start=45

[DoubleOSeven]

Some disagreement and Haynes is vague with respect to early vans.

I’m therefore going with:

Thermo Switch : carb heater + auto-choke*

IGN. 12V (2,5mm red wire) : solenoid + manifold

^^ this matches what I have in terms of feeds, ie only two feeds off thermo switch.

* late vans auto-choke have permanent IGN. 12V

[trundletruc]

You might find this link interesting? I wired my choke to turn off with the manifold heater and it seems to be okay. https://club8090.co.uk/forum/viewtopic.php?f=37&t=166532" onclick="window.open(this.href);return false;

[Mocki]

The inlet manifold heater needs to wired through the relay triggered by the thermo switch , as does the carb heater , the choke and the fuel cut off from the ignition switched live

[DoubleOSeven]

Went with this, so I don’t have to share feeds. That thermo switch has a lilac/black feed from relay and two black outputs, carb heater & choke. I put the 2,5mm red to the hedgehog/manifold, which also had a red wire. I put the black ign. 12V also from the relay loom to the solenoid on the carb. Remain unconvinced. Can someone post an ‘early’ bus photo of their engine bay?

[DoubleOSeven]

Anyone, Bueller?

[Ads1987]

I'm playing the same game you are so will let you know when I hopefully work out the answer.

At the moment i have the lilacl/black connected to the thermoswitch

12v thicker red wire is connected the manifold heater, this is piggybacked and connected to the carb heater which then piggybacks to the carb choke.

However I also have a green wire with black stripe that is not connected to anything at the mo, so still needs work,