Hi. I have 2001 X reg Punto HLX with a 1.2 16v petrol engine. The number 2 cylinder is not firing. I have tested the spark plugs and also moved the number two spark to another cylinder and vice versa. The number 2 still fails to fire. I then took each spark plug out int turn, fired the engine and held it next to the head. All but the number 2 produced a spark. Next, I tested all of the HT leads (1 & 2 around 14000 ohms and 3 & 4 around 13000 ohms). I then plugged the number one lead into the number two port on the coil and this one then did not work. At this point, I am thinking that it is not the leads or the plugs. So, I tested the coil circuits (I know that if it was the coil then two plugs would be down but I thought it was worth a shot). The primary circuits were both around 7000 ohms and the secondary circuits were both around 22000 ohms. Could it be the ECU not giving the firing command, or have I missed something easy? Has anyone got any ideas please?

Can't be the ECU -- given that your car is not coil per cylinder, but wasted spark, the ECU will fire the pair together regardless.

I'm inclined to think you have an internal issue within the coil pack itself. Try swapping the coil packs round (assuming you have the 2 x 2 type) -- does the fault follow the switch?

Thought the 16v had a coil pack per cylinder or is that just on mk1s?

Certainly not the Mk1s. The very late cars have coil per cylinder (completely stupid idea, but..........)

Thanks guys. The coil is one single moulded unit with one three pin plug in and four distributor ports out. Is there anyway to test this for a fault apart from the test that I have done?

the only 16 valve coil i have in stock off a 54 plater is a single coil not a twin
not sure with a 51 plate
but it does sound like a faulty coil
a lot of cheap copies usually dont work properly when you get them out of their white box

seen it wi me own eyes

The real FIAT or Webcon ones are about £50.

If I get a new coil, is it just as simple as old one off and new one on, or do I need to do anything for the ECU to accept it? I will phone around the car parts shops tomorrow and see what I can do.

plug and play

Cheers, I will sort one out tomorrow and report back!!

The coil packs have two separate coils inside. Each winding has to drive both plugs in the pair so a weak winding might only spark the best plug. If the plugs are changed and the same cylinder still fails to spark it has to be an issue with that plug lead.

I dont know if a failing ECU coil driver circuit can cause a weak spark voltage rather than no voltage, but if it can that might also fire at only one plug.

WhiteSei said:

The coil packs have two separate coils inside. Each winding has to drive both plugs in the pair so a weak winding might only spark the best plug. If the plugs are changed and the same cylinder still fails to spark it has to be an issue with that plug lead.

I dont know if a failing ECU coil driver circuit can cause a weak spark voltage rather than no voltage, but if it can that might also fire at only one plug.

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he says he tried another plug lead in the no.2 coil so he ruled out a lead

its got to be the coil

I have phoned around this morning and the cheapest I can find locally is one made by Intermotor for £74.00. I have never heard of this make before. Is it worth it or should I try the local breakers or ebay?

fiatpuntodriver said:

I have phoned around this morning and the cheapest I can find locally is one made by Intermotor for £74.00. I have never heard of this make before. Is it worth it or should I try the local breakers or ebay?

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74 is a little expensive
IF its a 2 coil pack setup

Look here at shop4parts, many of us here use it
http://shop4parts.co.uk/?name=store...2&secondary=53&opts=51&btnViewProducts=Search

Ziggy

Try Big Mick on 01332 345869

Ziggy122 said:

74 is a little expensive
IF its a 2 coil pack setup

Look here at shop4parts, many of us here use it
http://shop4parts.co.uk/?name=store...2&secondary=53&opts=51&btnViewProducts=Search

Ziggy

Click to expand...

It is one single moulded unit with one three pin plug in and four ports coming out. The whole unit would need to be changed.

fiatpuntodriver said:

It is one single moulded unit with one three pin plug in and four ports coming out. The whole unit would need to be changed.

Click to expand...

with postage the S4P is 80.11

so the Local ""Auto"" shop version probably is a better bet....

Ziggy

fiatpuntodriver said:

It is one single moulded unit with one three pin plug in and four ports coming out. The whole unit would need to be changed.

Click to expand...

with postage the S4P is 80.11

so the Local ""Auto"" shop version probably is a better bet....

Ziggy

Thanks for that. Are intermotor an ok make? I have not bought any of their products before.

Did you try Big Mick?

Failing that, there's this.