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[JamesV6CDX]

RE. my project 2.0 that I was having trouble starting.

I figured that because it was trying so hard to start, and was almost firing, that it must be soaked plugs. So I changed the plugs for a spare set, and sure enough with a bit of cranking, it fired up. However it was running lumpy, and then cut out after about 15 seconds. then it wouldn't restart.

I was trying again to start it, but this time with the jump leads because the battery was dead. When cranking, I noticed that the jumplead literally caught fire.

I immediately took the lead off, and at this point walked away for 24 hours.

When I put a charged battery on it the next evening, it woud hardly turn the engine, and I noticed that within 20 seconds of connecting a battery adn turning the key - the connector on the positive battery lead was RED hot.

So immediately took it off.

Now I've obviously created an electrical problem and I've no idea what to do.

suggestions please?!?

[CaptainZok]

Dunno how big a job it is but how about swapping the starter motor in case its been damaged with all the cranking assuming the one from your old engine is available.

[JamesV6CDX]

considered that, and I DO have a spare, however, would a burned out starter cause the lead to get red hot in a matter of seconds?

[theolodian]

considered that, and I DO have a spare, however, would a burned out starter cause the lead to get red hot in a matter of seconds?

It's the only thing that I can think of that can pull that much power without burning cables in the car.  It is the only thing with a high-current cable running to it.

[CaptainZok]

Well if there's a major short in there it could.
Remember there's no fuse in that line so a short would draw whatever current the battery could supply, limited only by the resistance in the jump leads which would cause them to imitate an electric fire element.
To get a bit technical Ohms law says current in amps = voltage in volts divided by resistance in ohms and the resistance of a thick piece of wire is minute so the current would be bloody huge.

[JamesV6CDX]

So you are saying if I've fried the starter motor it could be causing a short?

[CaptainZok]

Yup

[JamesV6CDX]

right, I'll try changing that as the first step then and post up the result

If iit's not that, is there anything else it could be?

[Andy B]

......
To get a bit technical Ohms law says current in amps = voltage in volts divided by resistance in ohms ......

Ah! I think I remember him from 'O' level fisiks!  

[theolodian]

right, I'll try changing that as the first step then and post up the result

If iit's not that, is there anything else it could be?

I suppose that the cable to the starter could be damaged, should be visible and at the ends.  Everything else should be fused, and you have tried with 2 batteries.

[STMO123]

Before you go to any more expense James, try and get someone to give you a tow and try bump starting it. If you get no joy that way, its more than just the starter.

[JamesV6CDX]

Can't bumpstart an Auto mate

[Markjay]

1. The jump leads catching fire is normal I’m afraid – most of the cheap leads they sell in petrol stations are far too thin for the job and overheat due to their high resistance. What’s the point in having a jump lead then you ask? Well Car Machanics Magazine raised the same question, and the manufacturers said that the leads are not intended for jump-starting the car, instead they should be used to top-up the battery overnight… which is rubbish.

I have always made a point of buying heavy duty thick copper jump leads, which you need to shop around for, and they do the job perfectly and without overheating.

2. As for your second problem, i.e. the positive terminal getting hot, it could be that the started motor is drawing too much juice from the battery, which would indicate an electrical fault with either the motor itself or the solenoid, or there may be a short circuit, and in this case it could be the starter motor but it does not have to be that – anything that causes a short circuit further before the fusebale link box will have similar a effect. The reason the starter motor is the main suspect for a short circuit is that it is one of the very few electrical components in a car that are NOT protected by a fuse - any other component failing would blow the fuse before the battery terminals overheat.

However I think that the symptoms you describe are compatible with a bad battery connection – a loose or corroded terminal connection would (a) overheat due to high resistance and (b) not supply enough current to rev the starter motor properly again due to the losses over the resistance of the dodgy battery terminal.

I suggest that you try first cleaning the battery terminals, make sure that the wires and connectors are clean and sound, and if the problem persists try another battery.

[theolodian]

Can't bumpstart an Auto mate

I wouldn't suggest it, but I have done it (not on a miggy tho').  

[TheBoy]

The amount of cranking you've done, it is likely you've killed the starter.  Also, may have damaged the battery internally.

Before doing too much more cranking, fix the problem thats causing it not to start, else you'll do another starter in.  If it doesn't start on first attempt, there is something amiss...