Starting issue/warm alternator!

[thegfb]

I have just replaced the fuel pump on my '61 S1 FHC after being recovered not far from Goodwood after the Revival! Couldn't get an SU pump so it's a Hardi that's gone on. Pump seems to be working OK and I had the engine running no problem after fitting it earlier in the day. However now the engine won't start and at first I thought the pump must be faulty. It is 'clicking' OK and I was about to slacken one of the banjo fittings on the front carb to check fuel present when it occured to me that it might be an ignition fault. Sure enough there doesn't appear to be a spark present at the plug leads. As I was looking around the engine I touched the alternator and it was very warm even though the engine hadn't been running. I left the ignition on for quite a period of time whilst I was checking things out and then went indoors to look on the web for hints and so it was an hour or more before I turned the ignition off. Is this normal for an alternator to get hot when the ignition is on but the engine isn't running? The distributor is electronic and fitted by a Jag specialist when I first got the car 4 or so years back. On their invoice it's listed as a Constant Energy HHL CE6 but I can't find any reference to this on the internet. I haven't checked the coil - not quite sure how to!
Any thoughts or pointers as to why the warm alternator and starting problem?
GF

[Heuer]

I would start by replacing the coil. Leaving the ignition on for that long can fry it - one of the first lessons I learnt from my Dad when we were playing with cars in the early '60's "Never leave the ignition on unless the engine is running".

[thegfb]

David

Thanks for this - I'll try the coil - is there a way of checking the coil in situ?
Excuse my ignorance and incompetence (as in leaving the ignition on!).

GF

[Heuer]

Not unless you have a very accurate ohm meter. It may have gone open circuit or shorted out. Best to replace with a known good one - ?15 from SNGB and always good to have a spare! Incidentally the alternator was warm because it was energised by leaving the ignition on. In the meantime check all connections and ensure you have 12v on the white wire to the coil with the ignition on.

[thegfb]

I will order a coil in the morning! I can't work on the car for a few days anyway. I've got reasonable quality multi meter but it may not be up to this particular task. I will check whether I have 12v to the coil via the white wire.

GF

[adv_rider]

On the coil, I think you should check resistance, not voltaje.
Also, some distributors use hall effect and don't have a protection, so if you levae your ignition on the unit is fried.

Like for example Pertronix .. their system 1 gets fried with ign on, but ignitor II has a protection against it by sensing the coil current level .
http://www.pertronix.com/prod/ig/flame/ ... itish.aspx
http://www.pertronix.com/prod/ig/ignitor/default.aspx

About the "constant energy" I found this, but i dont think is the case.. go down to "Lucas Constant Energy ignition"
http://www.jag-lovers.org/books/xj-s/05-Lucas.html

[MarekH]

The classic way to measure a very small resistance is to put it into a circuit which has a constant current flowing.

You measure the voltage across the component and the current (in series) in the circuit and use Ohm's Law (V=IR). You can measure V easily enough and you can use the meter to measure I easily enough, so R must equal V/I.

One of those small wall mounted multi-low voltage units ought to do.

kind regards
Marek

[thegfb]

One suggestion was that the coil had lost it's connection to earth due to a film/corrosion developing between the circular retaing clamp and the body of the coil. On my car the coil is sited underneath the header tank and I haven't worked out how to remove the coil (to clean up the 'join') without removing or at least moving the header tank. Even the latter would require the hoses to the header tank to be disconnected and presumably I would need to drain at least some coolant from the system.
In trying to get a screwdriver onto the clamping screw of the bracket with coil in situ and sockets/spanners on the bolts holding the the clamp to the chassis member I must have disturbed things enough for the earth connection to be made once again and the car fired up OK.
Now I need to work out how to remove/move the coil and clamp to clean up the interface between the coil and clamp properly! Any ideas?

GF

[christopher storey]

The case of the coil should not need earthing . The low tension circuit consists of 12 volts to the coil from the ignition switch , and then the other LT terminal
should have the white/black wire which goes to the contact breaker and thence to earth . When the points are closed, the circuit is complete . My guess would be that when you were fiddling with it, you have jiggled the connections and restored the circuit. Cleaning all corrosion off the terminals is probably a good idea, and also check both wires to the LT circuit of the coil, because fatigue failures are not uncommon - the outside of the wires can look fine, but the strands inside are gradually breaking up

[Heuer]

Agree with Christopher, the Bosch 'Blue' coil for example is covered in (blue) shrink wrap so the case is most certainly not earthed and that works on an E-Type. Give up on removing the coil and check all the spade connections for dry joints. Also suggest you remove and clean the coil spades, held in place by small nuts.

[thegfb]

Thank you gentlemen. I will do as suggested re checking wires, cleaning terminals, connectors etc.

In my long gone youth I do remember having a car with a coil that actually had a screw terminal on the metal body of the coil which I think was for an earth wire but I guess that would have been due to a non metal coil mount perhaps.

Another question! The water pump pulley - should this be steel or aluminium?

GF

[christopher storey]

All the pulleys usually are steel, but don't let it worry you if you have an al2 one. One of the things one learns about Es as you get older is that over 40-50 years, innumerable alterations have been made. Although we all tend to prize originality, not all of the mods are retrograde steps !

[thegfb]

Mine is ally and it's producing an annoying, high pitched, resonance which I haven't heard on a steel pulley equipped engine. It's a different sound to the loose fanbelt type of noise. An application of tyre fitters yellow resin like 'chalk' to the rotating belt silences the noise but only very temporarily. Time to spend the ?50 or so with SNGB for a new steel one I suspect.

Has anyone else had this issue? Any suggestions other than replacing the pulley?

GFB

[PeterCrespin]

...I do remember having a car with a coil that actually had a screw terminal on the metal body of the coil which I think was for an earth wire but I guess that would have been due to a non metal coil mount perhaps.
GF

What's your name GF? Geoff?

The coil never needs to be earthed is what Chris was saying. The low tension circuit involves a power feed whose circuit is completed through an intermittent earth (the points). When the points open, the high tension circuit involves the same power and same earth, but this time the electricity flows by way of ionized air, AKA a fat spark, to the same earth. Or via your fingers to ground if you poke around a running engine...

The casing can be mounted in foam rubber like the fuel pump and it wouldn't matter. In fact I used to do this on my highly-vibratory race bikes.

The E-type coil position is actually sub-optimal except for modern potted resin coils. Oil-filled coils should really be mounted vertically, so the oil can flow round the windings by vertical convection currents. They are less likely to leak that way too, although slightly more prone to water collecting around the king lead.