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Starting issues
ibakes - 29/6/24 at 08:05 PM

Evening all.
I posted the following on the megasquirt Facebook page. I jut a bit stuck and after inspiration for my westie. It's so close to going back on the road but keep taking one step forward then one back

Evening all
I'm just finishing putting my car back together and had my car starting and idling with no problem.
It started each time and I ran through the warm up auto tune on Thursday, all was OK it stopped and started after this.
Later on Thursday while checking the alternator I touched the positive feed to the exhaust which caused a spark.
I since then. I can't get it starter. It just won't catch.
All fuses seem to be fine
I have spark, fuel, revs on turn over, charged battery

Any ideas would be greatly appreciated. I was hoping to play with the fuel auto tune a bit today

I'll get the map and logs uploaded shorlty

I'm not sure if me grounding the power quickly caused an issue and racking my brain but I haven't changed anything else.

Duratec 2.0 ms3 ford edis


gremlin1234 - 29/6/24 at 08:23 PM

most likely you have fried one or more diodes in the alternator, causing them to short. easiest test is disconnect the alternator from the circuit and try again.

reminds me of Marvin the Paranoid Android, and all the diodes down his left side :-)

edit, thinking about it a bit more, the fault above would just rapidly discharge the battery.
but still worth disconnecting the alternator and trying again


[Edited on 29/6/24 by gremlin1234]


ibakes - 29/6/24 at 08:33 PM

I'll give that a go in the morning

My test battery is old but 70A and did discharge quickly when turning it over

Would that cause the car not to fire. It doesn't even catch and then stall out

Guess that also means a new alternator

[Edited on 29/6/24 by ibakes]


gremlin1234 - 29/6/24 at 08:57 PM

no, you are right, the symptoms make little sense,
I had a similar problem recently and giving the coil a better 12v feed while cranking allowed it to start. (conventional Lucas style circuitry)


ibakes - 29/6/24 at 09:19 PM

Its definitely worth disconnecting as a test so thank you. Cranking revs are at about 300rpm. It has backfired slightly from the exhaust a couple of times after winding over for quite some time

It's going to end up being something stupid that I have missed as usual


gremlin1234 - 30/6/24 at 07:40 AM

ah symptoms that sound like you have soaked the plugs with fuel,

so you may need to take the plugs out and clean/dry them.

I hope you put the battery on charge overnight too


40inches - 30/6/24 at 09:58 AM

I recently had the same problem.
It was a faulty cell in the battery. It was showing 12.5v, but dropping to 9.5v when cranking.
New battery and all is good


ibakes - 30/6/24 at 02:09 PM

Thanks all

Right battery fully charged (made that mistake before with a duff battery, voltage dropped too low)

I had my old ms1v3 which i plugged back in, this had started this engine before being changed out, this had the same issue so it not the ecu

alternator disconnected and still the same issue

Looking at the spark plug, slightly sooty and they do have fuel on them, so cleaned up and put back in, still the same issue.

I'll keep looking

I'm still in hope that i can take my son to school in it before he moves to secondary school and will be too embarrassed

[Edited on 30/6/24 by ibakes]


ibakes - 30/6/24 at 02:31 PM

Am I missing something, sorry i should have said I was using a spark light for my tests

If I remove a plug, rest it against the exhaust manifold and crank it over, there is no spark.

If the plug is floating, (just dangling from the lead) there is a nice spark.

[Edited on 30/6/24 by ibakes]


gremlin1234 - 30/6/24 at 05:56 PM

quote:
Originally posted by ibakes
Am I missing something, sorry i should have said I was using a spark light for my tests

If I remove a plug, rest it against the exhaust manifold and crank it over, there is no spark.

If the plug is floating, (just dangling from the lead) there is a nice spark.

[Edited on 30/6/24 by ibakes]

those symptoms are just weird, exactly the opposite from what I would expect,
I can't comment more without knowing more about the spark test device.


ibakes - 30/6/24 at 07:29 PM

amazon link

It's one of these. So it tests that the spark is there but not the spark plug

I did actually see that sparks were coming from a lead that was hanging with no plug in to the exhaust manifold


ibakes - 3/7/24 at 10:03 AM

Right, I thought I had posted the update but cant see it

anyway, issue was the spark plugs, new ones have been fitted and no issues, car starts fine and sounds great

hopefully get the MOT soon and back on the road


jacko - 3/7/24 at 05:13 PM

Glad you found the answer 👍
I once had an problem like this with a grass cutter new plug and hay presto
The answer is start with the easy bits first 😜🫣