K-series sudden-stop (electrical)

[Myles]

Not sure if this is much of an update, but anyway...

 

Didn't get to play last weekend as was away sailing

 

Gf out at Dancing on Ice today, so fired it up.

 

Checked one plug for fouling before starting - didn't look too bad, but didn't look too clean either.

 

Disappointingly, despite having a brand-new Powervamp battery that has been on trickle for two weeks, the emald took quite a while to recognise rotation. Might try the spare crank position sensor tomorrow after all...

 

Got it running, checked everything I could via the live adjustments page etc. - could't see anything amiss. Wiggled loads of wires - no problems found.

 

Idle was not dead-steady - lost of little variations, but not hunting. Restarted it once ok (bit reluctant as usual).

 

Then, whilst idling, the engine faltered a bit, I tried to give it a tickle on the jenveys by hand - and the revs just died. Sounded like the injectors were still firing (as happened on one occasion previously), so I killed it all. Checked a plug again - and decided to buy some new ones as I had nothing really left to try and nothing to lose. Forgot how hard it is to buy bits in halfords for a kitcar unless you know exactly what the original application was. I had a brain-fluff and rather than waste any more of the girls time, I googled t hat (yay! For blatchat! 😬).

 

Fitted the plugs, fired it up (reluctant to recognise rotation again - and took a while/few goes to fire even when it did) - seemed to idle as well as ever, so took it for a spin - first to the local garage (yay! It restarted!) and then on a five-mile round trip to a local farm shop for decent eggy-pegs. Which is where I found I had *exactly* enough pennies for half a dozen and absolutely no other cash on me.

 

Anyway, ran it back and gave it some beans - seems ok (but feels one hell of a lot slower than my blackbird-engined Westie BEC due to the totally different power deliveries). Rain was just starting, so put it straight in the garage.

 

I'm not sure this really advances things a much - I plan to get Emerald to send me a copy of the map they did (just in case it has been messed up by myself at some point in the past) - but I feel somewhat more confident that I can get to the mot station in the next week or so without cooking out as many times as I did last year!

 

Being as I've got an older emerald that hasnt been updated, can anyone confirm what the max ignition-trims setting should be (roughly) - mines set to 8degrees at the moment - mine doesn't seem to have the cranking-enrichment map and all that...

 

[Myles]

Well I fitted the new alternator today. Quite pleased just from the relative ease with which I managed it given the confines of the garage and the fact that I've an Apollo tank in the way of the removal.

 

I'll possibly post photos of the old alternator when I get a chance - I knew that the plug-side was heat damaged - but next to the new one, it looked really quite bad.

 

On firing it up (thought it would never spin fast enough for the emerald to recognise rotation - mebbe need to get my charger checked out too...) the volts looked much healthier than I remembered - and it was perfectly happy with the fan and lights on too. I topped up at a petrol station after just two miles or so - and the engine restarted convincingly at the first attempt.

 

Took it for a run - again, the volts looked happy even from the usually-depressing SPA gauge (I lose a good half-to-one volts somewhere in the nest of wires). So next problem (assuming it begins to restart with more confidence) is the cooling.

 

The rad keeps the car cool when properly on the go, but just can't cool it properly in traffic. I measured the volts at the fan when I got back (engine running) and it was actually higher than st the battery!!! I've seen this before and can only guess that I've electrolytic corrosion going on between the rad and chassis!!!

 

I've cleaned out the old single-pass rad and will obtain a fitting kit for my fan - if that doesn't solve it, I don't know what to do next.

 

I suspect I've still got starting issues though.

[Jonathan Kay]

Quoting Myles: 

I measured the volts at the fan when I got back (engine running) and it was actually higher than st the battery!!! I've seen this before and can only guess that I've electrolytic corrosion going on between the rad and chassis!!!

 

Was that using the same earth point for both tests?

 

Jonathan

[Myles]

Nope! I usually measure the battery voltage direct across the terminals - and because I was on my own (and the dvm leads aren't that long), I measured the fan voltage from the positive supply to the nearest convenient bit of chassis... Earthing has never been my strongpoint, but shouldn't it all be more or less the same given that they're all tied together???

 

I think I know the answer to that question - given the one you just asked - but, erm, well - eh???

[Jonathan Kay]

Yes, earth potential should be the same everywhere, but I'm not yet convinced by your electrolytic theory, and would like to remove some variables...

 

Jonathan

[Myles]

I'll test it tomorrow when I'm back at the gfs. I'm pretty sure I've measured a potential-difference between the rad and chassis with the battery isolated before....

[Myles]

Update.

 

Bought some long leads for the dvm with monster crocs on them. The car has sat out of the garage for the last week as I've been protecting the Westie that will be doing 3-4k miles around France in a couple of weeks - so it has not been on the charger this time.

 

Had to move the car today so fired it up. Prob took two or three long, long churns to catch.

 

The voltage across the terminals dropped to mid-tens. I'd say it was a bit more vigorous than before - and two/three long churns is actually pretty good recently!