Complete lose of all power!

[timjsparrow]

Hello all

I have an eletrical problem and I'm not sure whats causing it!

The symptoms:

She's travelling along quite happily but then suddenly the engine cuts out and I lose all electrical power.

She did this to me two days ago, but I found that one of the low tension leads on the coil was slighty loose, so I tightend that up and she was fine and got me to where I was going. However, upon leaving for the return journey exactly the same thing happend. Engine cuts out, and the lights drop to a very small amber glow. I try to turn her over again but this time only the starter motor spins.

The LT leads on the coil were still fine, and I'd already replaced the condenser and rotor arm before discovering the loose LT lead.

I've got spark at the points but not at the plugs. The coil is only four months old, but I have had this same cutting out problem about three times in the last year where replacing the coil has done the trick for a while, but then the problem rears its head again after a few months.

If it is the coil, then she's got through 4 coils in one year, what could be causing them to fail so regulaly?

Any ideas? Could the problem lye somewhere else?

Many Thanks

[brucek]

It won't be too long before someone confirms, in no uncertain terms that it is notthe coil!!

Best to check the earth points which, if weak could explain the complete loss of all electrics. Firstly check the battery earth (either + or - depending upon how your car is set up) surface contact should be clean and free from grot and debris. Also check the gearbox earth (between the gearbox casing and the gearbox cross member on the underside of the car. Again should be clean and secure[frame][/frame]

[MarkyB]

It's only "never the coil" if the right one has been fitted.
As the lights are going dim too check the earths and battery connections paying particular attention to all those to the solenoid.

[bmcecosse]

Lights going dim suggests a short circuit... but could be bad connections or earths. Is NEVER the coil - so a car needing 4 new coils in a year is either damaging them in some way - or being fitted with incorrect coils.... original coils last FOR EVER...

[David W.]

Looking at the picture above begs the question:
With the steady cable, isn't the earth cable redundant?
If there is a good earth on the engine, why the transmission?
David

[mogbob]

The earth on the gearbox was part of the design.Electricity always tries to find the easiest route to ground ( nature's example is lightening/ man's solution... lightening conductors on tall buildings )..why decrease it's chances on a car ?
Bob

[bmcecosse]

There is normally no engine earth.

[stag36587]

There is normally no engine earth.

Though I fitted one in vain attempt to solve my ignition probs.

[lambrettalad]

you can't have too many good earths.
Lots of people have had burnt fingers from the electrics trying to earth thru the choke cable which gets very very hot

[MarkyB]

The gearbox steady cable should be at neutral tension so not a reliable earth point.

There is normally no engine earth

News to me, you need as much earth as you do power for the starter motor.
As lambrettalad says, the choke cable is the next best thing if no proper earth is present from the rubber mounted engine and gearbox.

[bmcecosse]

But I say again - normally there is no ENGINE earth.....the strap is on the gearbox....

[MarkyB]

Where it is attached isn't relevant, it still earths the engine.

[smithskids]

Sometimes if the points stick on the petrol pump it causes a 10 to 15 amp drain on the battery and the pump stops then the car stops , see if the points are burnt, it only takes 5 mins to check.

[bmcecosse]

If the petrol pump draws that amount of current - it will soon be on fire!!! Stand clear!!!!!!

[JOWETTJAVELIN]

It won't be too long before someone confirms, in no uncertain terms that it is notthe coil!!

Best to check the earth points which, if weak could explain the complete loss of all electrics. Firstly check the battery earth (either + or - depending upon how your car is set up) surface contact should be clean and free from grot and debris. Also check the gearbox earth (between the gearbox casing and the gearbox cross member on the underside of the car. Again should be clean and secure[frame][/frame]

That earth strap looks rather stretched, brueck.

[bmcecosse]

It all looks disgustingly clean...........

[brucek]

JJ - I agree - I 'nicked' the photo from David Miles pick up rebuild thread and that was mentioned to him too. It should be mounted on the upper of the bolts securing the gearbox steday cable

[JOWETTJAVELIN]

Goodo - we don't want anything being ripped from its mounting.

[timjsparrow]

Right, one of the problems has been solved, I had a dying battery .

All the earths have been checked cleaned up and cheacked again and appear to be fine.

However, she still won't fire!

I've gone through all the usual checks. The coil is fine and I've got a spark at the pionts but nothing at the at the plugs. I've changed the condeser, rotor arm, dissy cap and HT leads but still nothing.

One thing I did notice when checking the spark at the pionts is that when I hand turn the engine I get a very good spark on the first turn but the the subsiquent ones are weeker.

Any ideas?

[bmcecosse]

Can only suggest points gap and condenser -again.