EML Light comes on when using electrics? fan/window heater

[frankko]

Hi all i have tried searching for info on this specific issue i have found similar but not the same,

 

i have a 2002/03 fabia 1.2 mpi classic 56k miles

My fabia EML has been on solid for about 3 weeks poor fuel poor idle etc
So iv changed the temp sensor (improved)
Changed plugs again improved
Idle is spot on now fuel consumption waay better
But

EML light cleared but now returnes flashing when sitting at junctions then when i pull away it stops flashing?
If i leave it ticking over it goes from flashing to solid with the cylinder 1 misfire code - iv noticed this only really happens if i have fan on or back window heater which i assume is draining elec from somewhere? as the idle goes from 8000rpm to around 7000/7500 rpm then the light comes on flashing? i put the revs up to 1500/2000rpm and the light stops flashing?
I have unplugged coil 1 and engine doesnt change?
I swap coil 1 & 2 engine doesnt change?
When i changed the plugs number 1 was black/oil looking to other 2 had better days but 1 was different
I have also added redex during week 1 of the issue

 

 

I have also contacted my local Skoda Dealer regarding the coil recall 28F7- is my car part of this recall ? they are saying its not and my coils are fine

 

Please any advice would be great im stumped, :S:(

[frankko]

sorry forgot to say i get fault code of misfire 16685

[sepulchrave]

Check your battery and alternator, it sounds like your battery may be marginal which can be caused by a faulty alternator not charging properly

[frankko]

Ah ok thank you would that lead to less elec getting to coils?

[sepulchrave]

Ah ok thank you would that lead to less elec getting to coils?

 

It can cause the random misfires at idle you report.

[spud31]

Agreed start of cold weather always shows up a poor battery

[frankko]

Ok just fitted a new battery and still seems the same? Will i need to reset anything? Or will it take time to sort out the idle?

[sepulchrave]

Have you tested the alternator, it needs to be giving 14.2V to 14.4V when the engine is running. Anything less means there's a problem with the alternator.

[frankko]

Ah i tested the battery when it was running it was 13 something :( could it be an earth?

Is it a nightmate to change the alternator? New belts n stuff?

Its totally fine until i use fan or rear window heater its really bad with both on at same time!

[frankko]

Hi guys iv fitted a new alternator this weekend and still no change :(

Idle is fine until i use elecs then drops to around 7000rpm then eml comes on with cil 1 missfire

New battery new plugs new alternator no change :(

Can it be a coil issue?

[sepulchrave]

It certainly can, coil 1 sounds dodgy, try swapping with coil 2 and see if the misfire moves to cylinder 2, if not then you may have a wiring loom issue to coil 1 or worse yet a problem with the valves in cylinder 1 which you can diagnose by doing a compression leakdown test.

 

Edit: Do you have the battery light lit when you first turn on the ignition which then goes out once you start the car?

Edited 11 February, 2014 by sepulchrave

[Haych123]

mine did this when i put the heaters on from cold all lights started lighting up as if the ignition was just switched on.. after a few revs it went off.. guessing its the battery or alternator.. never done it again after the one insident..

[frankko]

The battery is new no issues with lights on dash after starting until i use elecs plus new alternator :( thinking its gotta be coils or wiring? Earth maybe?

[frankko]

Hi guys, iv just checked the voltage on the replacement alternator and the voltage is 17v is this normal? iv read that it should be 14v,

 

how can this be? any advice welcomed im really stumped now,

 

also getting an intermittent error code of cil 1 circuit fault + the cil 1 misfire,

 

no EML while driving, all driving is ok , idle is ok turn on elcs/lights/fan/window heater drops from 800rpm to around 700rpm then light comes on flashing about 5 or 6 times then if i rev engine above 2000rpm light goes out

 

if i do nothing EML goes solid with cil 1 misfire error code

 

any advice welcomed thank you

[sepulchrave]

17v is way too high , does your MPi must have a separate regulator module, you need to check this.

 

Is it measuring 17v at the battery, if so you'll be boiling the battery dry, not good.

Edited 12 February, 2014 by sepulchrave

[frankko]

Ok thanks is that not part of the alternator?

[sepulchrave]

Ok thanks is that not part of the alternator?

 

It should be, have you been supplied the wrong alternator perhaps? Earlier MPi's had a separate module.

[frankko]

The alternator is off a 2002 1.2 - 3 cylinder fabia petrol iv asked the supplier they said it was working car so unsure whats going on :( it does have a bit on the back of it where the wiring goes into would this be the regulator? How would i check it? Seems crazy that the old alternator was giving not enough volts now this one is too much iv just been out and checked earths etc and its reading bang on 16.4v when idling too dark now to try anything else

Youd think that with 16.4v everything would run better/faster not worse and nearly stall :(

Thanks for your help so far

[frankko]

Hi can anyone help on this? Iv now tried swapping the coils round car is perfect idle 800rpm until i turn on lights/heater/back window heater then it drops revs for 1sec to 750rpm then comes back up to 800rpm but then starts swinging / hunting between 750-850rpm then the EML flashes about 10 times then goes solid

If i increase revs while eml flashing it goes out

Or if i keep revs around 1000rpm it never comes on?

New battery

Replaced alternator 14.6v reading

New plugs

Swapped coils

Issue always cylinder 1 misfire

Im stumped :(

Can it be mass airflow? Or lambada?

If i never used elecs it never comes on

Plus just lights on its fine but lights + fan or window heater it comes on

Any advice would be great thanks

[sepulchrave]

Clearly this problem is load related, the alternator is obviously putting too much load on the engine at idle and the ECU is not compensating, I suspect a problem with the load sensor wiring, you need to trace this back to the ECU and make sure there are no breaks anywhere in the wiring and that the plug is properly connected to the alternator and making good contact.

[frankko]

Thanks for your response, is there a load sensor or is that the ECU? Would it likely be from alternator-battery-ecu wiring or can it be anywhere?

Is there anyway to test the wires/plugs with a voltmeter? Or is it purely looking for broken wires?

Sorry for all the questions its really hacking me off!!

Thanks again really apprieciate it

[TMB]

Alternator load signal wires snapping is a common issue. They normally break at the plug near the starter motor...

 

http://www.briskoda.net/forums/topic/252312-broken-wires/

[sepulchrave]

Thanks for your response, is there a load sensor or is that the ECU? Would it likely be from alternator-battery-ecu wiring or can it be anywhere?

Is there anyway to test the wires/plugs with a voltmeter? Or is it purely looking for broken wires?

Sorry for all the questions its really hacking me off!!

Thanks again really apprieciate it

 

The load sensor is part of the regulator/rectifier assembly on the back of the alternator, it has a small plastic plug plugged into it with two thin wires attached, the battery cable is the big thick one and that isn't the one we're worried about, it's one or both of the two thin wires that is/are possibly broken, these wires go back to the ECU and tell it how hard the alternator is working so that the ECU can adjust the fuelling/timing trim to suit. If you have aircon switching it on will have the same effect on the ECU since the engine load at idle is increased.

 

Yes, read the fault codes for diagnostics, it'll probably say 'implausible signal from alternator load sensor'.

Edited 16 February, 2014 by sepulchrave

[frankko]

Thanks guys il have a look at the wires tomorrow the only fault im getting is cylinder 1 misfire nothing else i clear it then its fine until im sitting at junction or parked with elecs on

Its not got air con so at least it shouldnt be as complicated i hope

Hopefully its an easy find thanks again for your advice il post an update tomorrow

[frankko]

Quick update

Iv had a look at the wiring from alternator / starter / battery and this plug looks to be the issue

Its from the front of the gearbox behind the radiator underneath the battery box area pretty close to the starter

Theres a blue wire hanging next to it thats came loose and the plug itself is cracked

Im going to get a replacement plug tomorrow