38 replies to this topic

[Steve-O 2014]

Can coils suddenly just die (or can the cold kill them?)

 

Got a gold coil fitted that runs from 12 Volt and (Non Ballast) Im guessing its supposed to have about 3.5 Ohm of resistance but its only measuring 2.2 Ohms so Im guessing its dead?

 

 

[sonikk4]

Yes they certainly can. I have been stranded when one went pop on my old RS. Bit of a trek home that night.

[gazza82]

Never had one die from cold but yes they can and do fail.

[Tamworthbay]

They can also die over a period of time but work just well enough until they finally die.

[dklawson]

Also, when measuring coil resistance, take the following three steps.

1. Before measuring the coil, hold the meter probes together and record whatever resistance value is displayed.
2. Mark and disconnect the low-tension wires from the coil, then measure the coil resistance.
3. Subtract the measurement in step 1 from what you find in step 2.  That's your coil resistance.

Your meter may not be displaying "zero" when there is zero ohms (meter probes touching each other) and the coil resistance measurement needs to be made when no other components might influence the reading (disconnect the wires from the coil).

[Dusky]

They can.

Most of the time they'll fail while driving and after a few minutes of lettign the coil cool down you can drive again ( for a while).

The factory coil of our 67' mustang did this on us on our first trip. Not pleased when going on a motorway and suddenly you lose ignition!

[KernowCooper]

If your Gold coil is one of the newer Lucas DLB 105s they are indeed proving to be unreliable and no dropped by Minispares for that reason, they have replaced to Lucas DLB 105 with the Intermotor MSC 105 made in their own factory and not the far east.

[Steve-O 2014]

How do you check if its the newer type? 

 

It has a sticker on that says 1042w 01/13

[Steve-O 2014]

The engine starts and runs for 3 seconds, bogs down and dies and the plugs are all wet like they haven't been firing and won't start again until they are dried… 

 

Strange thing is it ran amazing the day before, and stuck the CO meter in the day before as was and was running at 2.8% so mixture seems good.  Plugs are brand new and leads new.

[Steve-O 2014]

Also, I have an unknown coil in the shed that measures 3.4ohms, can I try this out to eliminate the coil as the problem or are coils car specific? 

 

 

Oh and I held the probes together before testing and the reading was Zero :)

[KernowCooper]

3.4ohms indicated the other coil is a 12v standard type, so yes try it to see it it sorts the issue out.

[Steve-O 2014]

Ok will try when it stops raining and the wind calms down lol...

 

thanks

[KernowCooper]

When you mention the engine starts and runs for 3 secs then bogs down and dies and the plugs are wet, are you sure the needle valve not sticking and its flooding the engine, can you not rev up once it starts?

[Steve-O 2014]

When you mention the engine starts and runs for 3 secs then bogs down and dies and the plugs are wet, are you sure the needle valve not sticking and its flooding the engine, can you not rev up once it starts?

 

hhmm I dont know, how can I check that?

 

All I know is it fired up, started and drove amazing the day before and also the night before, then the next morning, started then ticked over for a few seconds then it sounded like the engine misfiring / loosing cylinders and then cut out. Removed the plugs and they were soaking wet.

 

All plugs are brand new as I had a problem with one not firing so replaced all…. But the strange thing is the plugs I replaced were only about 1,000 - 2,000 miles old which is making me think the problem is a weak spark requiring clean plugs to make a good enough spark to get the car running and that there was possibly nothing wrong with the plugs I replaced...

[dklawson]

Or... your carb's float valve is stuck and over fuelling the engine.  Which carb does your engine have?