Difficult to start from cold.

[bnicho]

Hi again,

I've tried priming the carbs, disconnecting the fuel pumps, leaving it for ten minutes then attempting to start it. No different.

It's a DOHC head with the cams acting directly on the buckets atop the valves. No lifters.







I just tried a little shot of ether again. I am cautious with Ether, I've seen it bend conrods before! It didn't even cough.

I just took this video with my phone.

http://smg.photobucket.com/albums/v662/ ... LjNncA.mp4

You can see the plug spark jumping and hear it seems to be cranking with good speed. It's getting spark and fuel, it has compression. So it has to be timing I suppose.

Cheers,

[Wicksy]

Looks really nice
One long shot before you start taking things apart - is the spark at the plug seen continuously during cranking on the starter? Is the ignition a ballast coil setup? You can see where I'm going with this - have you cheked for 12v at the coil during cranking?
The theory being an open circuit on the 12v starting feed a but the 6v feed comimg in on key release when there is still enough inertia/crank rotation left to get a spark for a hot start but not when cold.
Well I did say long shot

[Luxobarge]

Looks really nice
One long shot before you start taking things apart - is the spark at the plug seen continuously during cranking on the starter? Is the ignition a ballast coil setup? You can see where I'm going with this - have you cheked for 12v at the coil during cranking?
The theory being an open circuit on the 12v starting feed a but the 6v feed comimg in on key release when there is still enough inertia/crank rotation left to get a spark for a hot start but not when cold.
Well I did say long shot

Maybe a long shot, but that's two of us, because I had exactly the same thought. I've seen symptoms like this caused by a faulty ignition switch before, due to the reasons Wicksy explains.

That's kind-of where I was coming from when I wanted to see if there was a spark under compression, but minitoring for coil voltage throughout the starting phase is also a very good idea.

[bnicho]

I thought of that too. It's a non-ballast system. I've tried running a 30amp cable from battery + to coil + to take the ignition switch out of the circuit. It made no difference at all. But I haven't checked voltage at the coil with the multimeter.

[Luxobarge]

Blimey, you've thought of everything! I agree, test the voltage at the coil while cranking, but I'm not sure that's going to give you a definitive answer.

Now I REALLY want to know if it's sparking under compression, to be honest. I think to be certain of this you need to use an in-line spark tester - like this one:

http://www.amazon.co.uk/Draper-38898-In ... 865&sr=8-1

(I just did a google search on "spark tester")

It can only flash if the spark has travelled across the gap at the spark plug, so using one of these is going to definitively tell you that all is well while you are actually cranking the engine. If there's no spark, then that doesn't tell you what the fault is, but it narrows it down an awful lot!

These things are only around a fiver (GBP) so in your case surely worth getting one?

Cheers!

[bnicho]

Mate, at this point I'm so frustrated with it, I'd pay someone to burn it.

I'll order one of those spark testers and give it a go.

Cheers,
Brett.

[valman]

If you try jump starting it from another car directly from cold, without any attempt to use the in-situ battery and it fires up first time, would this then also point towards the need for a more powerful battery? or at least eliminate this as the reason for your problem?
With a bit of help you could also get someone to check the voltage at the in-situ battery terminals with / without jump leads in use whilst turning over the starter motor. This might provide some more factual evidence for what's going on.
I assume you are running a negative earth system? Should the earth terminal really get warm ? I suffered from this on a '68 Renault which was a result of a poor earth connection at the body. Maybe a quick check of the engine to body earth connections, body to battery earth connections is worthwhile?

Good luck. Mike V

[Young Farmer]

I had a similar problem with a '77 Hillman Avenger 1.6 with electronic ignition. Used to start first time every time regardless of weather. Starting from cold suddenly became difficult Found a wire had dropped off the starter solenoid which bypassed the resister to the coil which then sent 12volts to the coil. replaced the lead and normal service was resumed. Try running a lead from the battery to the coil and see if that starts it. Best of luck
Dave

[bnicho]

Already tried that young farmer. No difference.

Valman, It doesn't fire right up when I jump-start it with another car. It cranks for a while, then fires up reluctantly, usually spitting raw fuel out the exhaust.

Something must be coming good with time/heat/rotation.

I tested another theory tonight. I turned on the ignition, let the carbs prime, then disconnected the fuel pump. I went inside and left the ignition ON for 10+ minutes to see if something heats up with time and starts to function. But still no f'n difference.

I am getting a healty 12v at the coil with the ignition on. But I haven't been able to test voltage while cranking yet.

I'm sure it's something I'm overlooking, but it has me buggered. In my 20+ year of playing with cars I haven't seen anything like this.

[bnicho]

I've been having another bash at this on and off since my last report, but for the most part I have been successfully ignoring the Corona,

Today I receoved a phone call from someone who wants to look at it tomorrow night. (It's been for sale for over a year.) I explained my issues with starting it cold but he decided it didn't sound too serious so he wanted to look at it anyway.

I went outside tonight to check everything was neat and tidy. I gave it a crank and as usual it just turned over without even a cough. I noticed while I was cranking the oil pressure light was not on. The sender wire had popped off the sender, so I went to reattach it.

That's when I noticed the wires from the distributor to the coil. For some reason they were always about a half-metre longer than they should be. I looked a little closer and I could see electrical tape with bare wire poking out. Hmmm...

After unwrapping the tape I found corroded bare wires twisted together that were not real well attached. They may have even be touching each other. Perhaps touching just enough to offer JUST enough resistance to porevent starting when cold.

I trimmed off the bodgy bits of wire, added properly attached spade connectors and connected everything back up. I turned the engine over with a spare plug connected to number one lead. It was immediately obvious the sparks were happening closer together and they also seemed brighter. This could be good!

I reconnected the lead, plugged the fuel pump back in, pulled out the choke and turned the key. She coughed, spluttered, then fired up and settled on a fast idle!

So it seems this dodgy connection was the problem all along.

I'm very relieved to have solution, but also very annoyed with myself for not finding it sooner.

Cheers,