13 replies to this topic

[R32Egor]

Hi all,

 

Does an spi need the engine earth strap that connects with the engine steady bar?

I replaced engine steady with nice shiny down steady and removed an old earth strap. I actually have an earth strap connected to the exhaust manifold under the car.

 

And now my engine will not start.

The engine will turn over nicely but not start. I cannot hear the fuel pump at ignition start.

I have checked the the shut off switch and this is fine.

Would the missing earth strap have an effect on the relays?

I can hear the stepper motor fine and the engine turns over fine so I presume the earthing is fine?

 

Any thoughts?

[nicklouse]

No good earth and you will not have a circuit on the engine. Often the engine can earth out through unsuitable cables such as the throttle cable.

 

get it fitted and check the condition of all wires.

 

ps it does not need to be over the stabiliser but must go from engine to BODY not subframe.

[R32Egor]

Hi

So found the problem 

Basically the earth of the fuel pump was not good.

But I do not know where the earth is actually connected to the body.

Because my rear lights are out at the moment I thought it might be some thing to do with that, and when I measured resistance between fuel pump earth and LH rear light cluster earth - they were directly connected.

So just to test I connected the light earth directly to battery earth and he presto pump runs and mini starts and runs.

 

So my question is where is the actual body earth connection for these 2 earths?

[Gaz66]

No good earth and you will not have a circuit on the engine. Often the engine can earth out through unsuitable cables such as the throttle cable.

get it fitted and check the condition of all wires.

ps it does not need to be over the stabiliser but must go from engine to BODY not subframe.

Done this and welded throttle cable to bulkhead 😬

[brivinci]

There must be an earth in the boot but there is a bunch earth that bolt directly to the body on the clutch side of car. Down where the reinforcement piece goes from the wing to the bulkhead. Above your brake proportion valve. Terrible at explain this. Anyway, there are several all bolted together with one bolt. Always worth checking their condition, knocking them all back a bit and where it mounts to ensure you are getting proper grounding.

[R32Egor]

I did all of the engine bay earth connections when i had the engine out.

 

I am just confused because the fuel pump earth surely cannot be anywhere near the engine bay.

 

So does anybody know if and where the boot earth connections would be?

[sonscar]

Between back light and petrol tank is where mine is on 1989 racing green.Steve..

[R32Egor]

HI all,

 

I found the electrical library manual and located the earthing point in the boot.

Its actually one of the connection bolts for the LH rear light cluster.

 

I will check again tonight as I do not remember any ring connectors loose in my boot!!

 

And i will connect the engine earth strap again but from gearbox as original - apparently my research says only the MPI's had the earth strap mounted with the engine steady, the others have it connected from gearbox to subframe.

[R32Egor]

Thanks All for the information - hopefully will sort this out by end of week.

[KTS]

 

And i will connect the engine earth strap again but from gearbox as original - apparently my research says only the MPI's had the earth strap mounted with the engine steady, the others have it connected from gearbox to subframe.

 

earth strap must connect to the bodyshell, not the subframe, which if on the normal rubber mounts is electrically isolated from the shell (..which is what the battery earth is connected to)

[stuart bowes]

even solid mounted.. it's all painted or powder coated, you won't get a circuit that way

[R32Egor]

Ok thanks.

 

Also just found the problem in the boot.

The 2 earth leads that should have been connected to the LH light bolt wre not connected and taped up

Don't ask me how the mini has been working fine with no problems for over 2 years now???

Anyway I will obviously connect the 2 earth leads correctly and I presume this will fix a problem that was never there

[nicklouse]

 

And i will connect the engine earth strap again but from gearbox as original - apparently my research says only the MPI's had the earth strap mounted with the engine steady, the others have it connected from gearbox to subframe.

Nope nope nope.

 

find a better source of information.

[brivinci]

Glad you found your issue! Always amazing to get a real answer.

Per Nick above, the earth strap needs to mount to the body NOT the subframe. That is why they were connected to the UPPER engine steady as other side of the steady bolts directly to the body. The lower engine steady goes from the breadbox to the subframe. Not what you want.