Series 3 Starter motor causing sparks on throttle linkage when turning engine

Hello everyone,
I can't remember whether I have introduced myself here but my name is Dom and I have a land rover series 3 109 station wagon, 2.25 diesel from 1982. Its very non standard as I have been slowly discovering throughout my ownership.

Anyway to the problem at hand, I started the car with the bonnet up the other day and noticed sparking and serious heat on the throttle linkage. The car starts fine if you give it some accelerator while cranking. If you don't put any accelerator it will turn slowly and smoke appears from various places depending on the day of the week. It sometimes just clicks and sometimes makes a rapid brbrbrbr sound. Mostly just normal starter sound though.
My attempt to fix this has been clean and test all grounds and the large high amp cable. I have noticed at the starter end that there is more wires than there should be connected, is this normal?
I would be very grateful for any advice. Thank you in advance

My first thought would be earths.
As you say you have cleaned them maybe it’s time to put a known good 1 from engine to battery neg. (Jump lead)

clean ends doesn’t guarantee good cable under the insulation. Especially at that age.
Identify the extra cables too may help.
J

marjon said:

My first thought would be earths.
As you say you have cleaned them maybe it’s time to put a known good 1 from engine to battery neg. (Jump lead)

clean ends doesn’t guarantee good cable under the insulation. Especially at that age.
Identify the extra cables too may help.
J

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I'll give that a go and update you identifying the cables could be a pain :/

Have you checked you have a high amp earth from chassis to engine block (usually bell housing)?

marjon said:

My first thought would be earths.
As you say you have cleaned them maybe it’s time to put a known good 1 from engine to battery neg. (Jump lead)

clean ends doesn’t guarantee good cable under the insulation. Especially at that age.
Identify the extra cables too may help.
J

Click to expand...

blue beasty said:

Have you checked you have a high amp earth from chassis to engine block (usually bell housing)?

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Thank you for the advice, I used the jump leads and tested the resistance over the ground connection (like 100 ohms!!), My positive cable is ok . I am going to get new earth cables for both battery to chassis and chassis to starter. The battery to chassis connection is poor, it's on to the battery box in the engine bay. Is the bell housing a good place to relocate it? Is there somewhere better to relocate it to?

Thanks again

Aflyingduckling said:

Thank you for the advice, I used the jump leads and tested the resistance over the ground connection (like 100 ohms!!), My positive cable is ok . I am going to get new earth cables for both battery to chassis and chassis to starter. The battery to chassis connection is poor, it's on to the battery box in the engine bay. Is the bell housing a good place to relocate it? Is there somewhere better to relocate it to?

Thanks again

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Normal setup is battery -ve to chassis and chassis to bell housing

Update, still sparking. No cable seen on engine to chassis though shall put one in now

blue beasty said:

Normal setup is battery -ve to chassis and chassis to bell housing

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Would the cable be top or bottom of Bell housing?

Aflyingduckling said:

Update, still sparking. No cable seen on engine to chassis though shall put one in now

Click to expand...

Ermmm yeah might not be a bad idea.

J

Doesn't matter where it is, but I think it's usually on the right side if looking in the engine bay.

No earth there would definitely explain the sparks, utilising the throttle linkage as the bridge between engine/starter and chassis.

Aflyingduckling said:

Would the cable be top or bottom of Bell housing?

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Normally near side chassis rail to a bell housing bolt at about 7 o clock but doesn't matter where

Ok, done for tonight now, not alot of progress to be honest used jumper cables and wired in an engine to chassis ground. Still sparking less than before tho. I think the problem is with the positive side but I am unsure. When I put the multimeter on the throttle linkage to the ground and crank it I get 4v ish. Think I've deaded the battery a bit so I've put it on charge will update with progress tomorrow

That 4v is the voltage needed for the ground to return to the battery, it should obviously be zero because there shouldn't be any resistance there.

That also means your starter is only allowed to use 8 volts, because of the 4 needed to overcome the earth fault.

Giving it a proper earth will allow it to use all 12v and spin over much faster.

You can see what wires should be connected to starter here
http://www.retroanaconda.com/landrover/manuals/series3wm/7_electrical_5mb_engine_supplement.pdf