Cilo 1.6 no spark please help!

[edk83]

Hi all. My friend bought a 99 clio 2 1.6 auto about 2 weeks ago. She got it from a family friend and knows that it has always been reliable and never had any major problems.

The problem started when the car started to cut out after about 15min of faultless driving and then fail to restart until left for a few hours. It always seemed to cut out when idle or changing from drive to reverse never when at any speed. I thought that it might be overheating but the cooling system is working fine so it has to be electrical.

Now it will not start at all and there is no spark from any of the ht leads. I swapped the coil packs and it still will not spark. The engine turns over fine and the battery is fully charged. I then checked the wires on the coil pack connectors with a multimeter and now I'm confused. There are 2 coil packs and each has a connactor plug. Each connector plug has 3 wires and on both plugs two of these wires are giving 12v and the other one nothing.

I checked the same two plugs on another working car that I swapped the coils from and with the igniton on 1 of the 3 wires is giving 12v and the other two nothing.

It looks like the ecu is putting 12v on one of the wires that should not be live, or only live when the coil packs are supposed to fire?

Can anyone help as I'm about t0 go and spend a load of money on a replacement ecu.

Thanks

Ed

 

[MicKPM]

Re: Clio 1.6 no spark please help!

I'm guessing its a 1.6 8v K7M here - The two coil packs do indeed have x3 wires per multi plug that supply them and they should be:

1. Ignition controlled live (+12v)
2. Trigger (ECM controlled Earth)
3. Noise Suppressor

I don't know the specific wire colours on your Clio II I'm afraid as they vary from vehicle to vehicle depending on platform and age however if you're 100% sure that you have two +12v lives at each coil then you've got a short to positive somewhere. I again make the assumption that you're testing these "lives" with the coil packs disconnected from the multi plugs (Yes/No)?

There are a few possible causes of this but we'll start simple; Firstly, check the entire wiring loom from the ECM all the way to the coil packs and you will have to strip back the protection from it to be able to properly inspect it. You are looking for any signs of damage such as cruched sections, bits that have rubbed through, etc. Repair any damage you find.

Once you've done this come back with your findings

Mick

 

[edk83]

Re: Clio 1.6 no spark please help!

I tested each pin on the multiplugs by earthing the multimeter on the engine mount with the plug disconnected from the coilpack and the ignition turned on. I also tested each pin while the engine was cranked with the same result.

Its odd how both multiplugs have a live pin that should be an earth/trigger. Is this going to be a single wire in the loom back to the ecu? Just wondering where the wire splits into two to go each multiplug and where the short is most likely to be?

thanks again

 

[MicKPM]

The +12v and suppressor lines will be a joint in the loom which doubles up the same wires to feed both coils but the trigger lines will be unique as one will earth out the coil to fire cylinders 1 & 4 where as the other will do the same but for cylinders 2 & 3.

The +12v and the supressor wires will be common in colour to both coil packs so if the unique colour wire on each coil is live then that's where the problem lay. It could potentially even be a ECM/Ignition driver fault but lets rule out the obvious and easy faults first... check the loom thoroughly for signs of damage and worn thru sheathing first.

Mick

 

[edk83]

Right had another look this morning. From looking at the plugs when connected to the coil packs the far right wires are different colours so they will be the trigger are they are not reading any voltage.

The other two wires are common in colour on each plug and the middle wire is +12v. The far left wire on the plug reads +12v but only when one of the plugs is connected to a coil pack. If I test this wire when both plugs are disconnected then it shows 12v but quickly discharges to 0. The same happens on both plugs.

So it looks like the wiring is ok and its just the noise suppression wire loading up when one of the plugs is connected? Makes sense to me, pretty sure when I checked the plugs on the other car they were both disconnected.

So now I know that the coil packs are ok, they have power but still no spark. So they are not being triggered. Looks like I'm back to crank sensor or an immobilser issue?

 

[edk83]

Bump anyone else got any ideas? Car is now stuck at our old house as we have moved!