Technical Abarth Loose Connection Issues

[HSSB]

re: Abarth - Earth Lead? [AND coil pack]

Checked voltage - again remaining relatively constant at around 13.98v even when gremlin acting up
But from where to where? And is this the same place as you saw the 28v appearing?
Checked from several places on side / front of engine , from towards the top to as far down as I could get to running back to the battery live terminal - and yes, it did include exactly the same spot I saw the 28v at (sorry for mentioning that again, I wince too). Sorry, I should have been more precise.

To check voltage when car is moving you can improvise and use an old something you don't need any more that plugs into your cigar lighter, chop the wires and securely connect your multimeter leads to the wires
Hmm, think I've an old light with a cigar lighter connection I can cannibalise. Will have a root around. Though now the glitch appears to be back at idle, am I likely to see anything different from measuring that to measuring via the cigar lighter method?

I have a sharp intake of breath whenever you mention voltages like 28v so it would be nice to never see those again
Other than the mention above, I hope to try and never see / speak of them again

It's a pity the Stilo only winges and fires warnings when there's a low voltage and says nothing when there's a high voltage

Might be me being thick (its been a long day, actually, seems to have been a long flamin' week, so not at my sharpest), but not sure what you mean on the last point there.. Do you mean the 'gremlin', which is showing at the voltages mentioned above, or is there a dash warning for high voltage detection (not seen that). Should I expect a dash warning if the voltage drops too low (again, never seen one).

 

[Deckchair5]

re: Abarth - Earth Lead? [AND coil pack]

No there's no high voltage warning, that was my point really. You only get a no charge (low voltage) warning light when the alternator isn't charging the battery. The best clues of low voltage are the abs and other sensors warnings going off or power steering failure

 

[HSSB]

re: Abarth - Earth Lead? [AND coil pack]

Ahh, becomes clear what you meant now - was me being a bit slow

But that give me a little idea - thinkin aloud here, so feel free to shoot this down if you want..

If ABS etc.. warning lights are a good indication of low voltage.. then

1) If I get multiple occurrences of 'the gremlin' consecutively, then it sets these very warning messages off - ABS etc..
2) I've noticed & posted above that the body - battery earth takes a small but sharp increase each time the gremlin occurs..
3) ...so if I get lots of occurrences in a short space of time, *theoretically* that could climb quite high if the effect was cumulative - i.e. rose from 0.1 to 0.11 to 0.22 etc..

...now while the engine to battery + voltage I measured seemed steady, with less than 0.5v variation (which I didn't think co-incided with the gremlin, but I can re-check as would seem a reasonable co-relation), suppose those small variations were gremlin related and could also cumulate if I got multiple occurrences within a short space of time into a pretty big voltage drop - could this be the trigger for the ABS sensor warning etc..

Does that sound logical?

Though this just explains why I get certain warning signs, and doesn't actually get me any closer to discovering the *cause* of the glitch and hence voltage variation..

edited to add - just thought - this doesn't explain the Power steering fail which occurs even with single incidences of the glitch... Scratch this theory?

 

[Deckchair5]

re: Abarth - Earth Lead? [AND coil pack]

1) If I get multiple occurrences of 'the gremlin' consecutively, then it sets these very warning messages off - ABS etc..
yes very likely as the voltage is spiking high (and low i would guess)

2) I've noticed & posted above that the body - battery earth takes a small but sharp increase each time the gremlin occurs..
that's your bad earth

3) ...so if I get lots of occurrences in a short space of time, *theoretically* that could climb quite high if the effect was cumulative - i.e. rose from 0.1 to 0.11 to 0.22 etc..
Not cumulative. Think of it as waves, but abrupt ones, above the normal sea level

Power steering will switch off if voltage goes too low as it needs lots of power

 

[HSSB]

re: Abarth - Earth Lead? [AND coil pack]

... which put me back at whats causing the voltage variation...

..so Alternator? I was advised to be looking at various things there but I must admit to having got a bit side tracked.. the brief 28v reading shook me a bit & I got rather obsessive about it down a particular track, though it doesn't appear to have repeated itself

I think I'll go back and refresh my memory and organise / work my way down a list of tests from all the recent posts afresh.

 

[Deckchair5]

re: Abarth - Earth Lead? [AND coil pack]

I'd take the alternator off, (it's a very quick and easy job) and take it for testing to an auto electricians or good autoshop. A duff or broken diode in there will cause mayhem to voltages as will a duff voltage regulator in the alternator

 

[Argonought]

re: Abarth - Earth Lead? [AND coil pack]

HSSB, Can you make a comment about the 'gremlin' before you fixed the bad earth and how it is afterwards (now)?

I don't mean in frequency but more in intensity.

Would you say it's EXACTLY the same or is it less intense or extreme?

 

[HSSB]

re: Abarth - Earth Lead? [AND coil pack]

Well, I would say less possibly less extreme, certainly in frequency. Not really sure about intensity as I hadn't really taken that many reading before touching the earths at all - seem to have been messing with them to varying degress for quite a while now.

Drove the car to work today, and only had about 5 occurrences in a 15 mile drive - all when stationary or low speed (engine at >1200 rpm), and no 'multiple occurrences setting off ABS lights etc... If I 'drive round' the problem by knocking into Neutral and keeping the revs up when stationary it helps immensley. Knocked off all extra electrical items (e.g. the air con, radio etc) in the car as well, just to see, so that may have also contributed to the improvement?

I've pulled all the posts from this thread into a single document & I'm going to work through it stage by stage over next few days from the start.

 

[Deckchair5]

re: Abarth - Earth Lead? [AND coil pack]

Drove the car to work today, and only had about 5 occurrences in a 15 mile drive - all when stationary or low speed (engine at >1200 rpm), and no 'multiple occurrences setting off ABS lights etc...

Do you mean <1200rpm ? Not being pedantic, just want to be sure

The only thing that's going around with the engine that affects voltage is the alternator

Take the alternator out of the system and see if the problem disappears

I'd remove the alternator drive belt completely out of the way and run the engine without the alternator going round. Just lever and rotate it off, watch your fingers though, and get the belt out the way and you may not even need to remove the aux belt like you'd normally do to replace the alt belt. Aux belt shown removed here

Dont go anywhere as elect power won't last for ever running just on the battery and you should get the no charge warning light on and a few other warnings of course.

Dont run your battery down too far

If it is the alternator then you've got the job half done to replacing it too

 

[Argonought]

re: Abarth - Earth Lead? [AND coil pack]

Anyway got the multimeter out, and the gremlin was present at idle speeds again (in force this time).

Checked voltage - again remaining relatively constant at around 13.98v even when gremlin acting up - no repeat of the 28v we had earlier, but I am absolutely certain that really did occur
Checked body - battery earth - reading 0.01v steady throughout
Checked engine - battery earth and that was fluctuating jumping from 0.01v at normal running to between 0.05v and 0.11v with each 'blip'

This has turned out to be a lot trickier than I first thought as it does seem two faults are involved but at least we're on top of one of them

There's a lot of info in the readings above and that leads to only two interpretations. Either there's another much larger earth cable connecting engine/battery which is going open circuit. This would need to be about 10 times thicker than all existing engine earths The trouble is, even if such a cable is found it still wouldn't explain the 'gremlin' as a drop of just 0.1 volts is nothing to a car! In any case it's difficult to see why you wouldn't have starting problems too.

That's means we only have the 2nd explanation.

This is that the 'gremlin' is connected with a current surge of something 5X to 10X to what the engine normally consumes. That's a lot and more than likely an actual shot circuit is taking place. One of the supply lines (note: I don't mean the battery - this has ample power to sustain the load) is likely to take a sizable drop in voltage and it's almost certainly this which is triggering the ABS/Power Steering errors.

So what do we look for?

Well we know it must be something bolted to the engine because the short only affects the engine earth and NOT the chassis earth. That makes sense as it would also seem the fault is mostly likely instigated by vibration or movement of the engine. Since the 'gremlin' almost disappeared after you'd had a bit of a play under the bonnet then it's also likely you got quite close to it.

Suggestions?

Electronic devices aren't good at sustaining multiple 'shorts'. They tend to 'blow' either short circuit (which should lead to a fuse going) or they go open circuit and stay that way. That also means they wont work any more so I think we can discount ABS & ECU control units.

Things which are good at multiple shorts are 'mechanical' things like a part of the engine crushing a wiring loom; a pinched wire or perhaps even a relay etc.

You say this all started after having new springs fitted so this means you need to add the human element :chin:

1. Any sign of a damaged/crushed wiring loom caused by jacking etc
2. Was a nut/bolt dropped into engine and is now resting on a live contact.
3. Was a tool dropped the same way?

with this in mind, just eye-balling the engine bay (and underneath) might give you a clue.

Even after considering all the above it still might be worth plugging in Examiner. Examiner will NEVER report "spanner resting on alternator terminals" but it might report something that provides a clue. Don't forget you should take the car for a drive with Examiner still connected and see what it reports when the 'gremlin' strikes.

If you want to get an idea of the magnitude of the short then you could measure voltage drop across both engine earth and chassis earth when the engine is started and post the results.

Good luck

 

[HSSB]

re: Abarth - Earth Lead? [AND coil pack]

Cheer guys,

Actually only just about to leave work, so that probably curtails much tonight

Should mean an early finish with plenty of time tomorrow though Quick post before I set off though..

Without having looked under the bonnet yet since reading these, coupe of things..

1) Yes, I did mean over 1200 rpm earlier.. apologies and I'm pleading frozen fingers as the excuse - its devilish cold here today.
2) Alternator belt runs inside of he timing belt (I think), but looks easy enough to slip at the alternator end. Should be possible to do if I'm careful in supporting the loose belt somewhere so it can't interfere with anything.
3) The front spring replacement was not done by my usual garage - just the nearest one as it was only place I could get to safely (one of the fronts went in a BIG way), seemed to have a fair few really young 'YTS' types there as well, so I've an element of mistrust there. Could just be co-incidence this happening so soon after that of course...

Okay, catch up soon as I have something more for you..

Cheers

 

[Deckchair5]

re: Abarth - Earth Lead? [AND coil pack]

On 2nd thoughts, on your setup, as your alt belt is inside of the aux belt, just loosen your alternator and loosen the alternator belt tension. It won't go around then, it will just slide on the drive pulley without turning the alternator pulley. That'll be safer than letting it dangle and whatever you do, don't stand there holding on to it

 

[HSSB]

re: Abarth - Earth Lead? [AND coil pack]

Morning,

New wrinkle. Too late to do much when I got home last night...

This morning, ran okay most of the way into work (only a couple of gremlins as well).. then 2 miles out started to miss... then a mile further 'Engine Control System Failure' and down onto what feels like 4 cylinders.

Same after a restart.. Feels like a coil pack has gone to be honest

Going to try & get away early, limp home & check it...

I don''t believe in co-incidence - related do you think? Could me my gremlin be a contirubtary cause, or was it possibly a symptom of a coil on the way out?

Out of interest I had no showing at all of the gremlin when the engine started to miss, nor afterwards even with the Engine Control System warning and the engine running lumpy...

 

[Argonought]

re: Abarth - Earth Lead? [AND coil pack]

In this case I'd say it was coincidence.

Can't see how a coil pack could cause a short and if it did then you'd be down to 4 cylinders anyway (I'd have thought :chin

Not totally clear what's you've done so far but I'd be inclined to keep the earth lead in place that you used to resolve the 28v reading issue. This is still one hell of a mystery to me but I'd be very inclined to keep that 2nd earth in place (just in case something is still intermittent on the earthing side). As Decks and I have commented, 28 volts can do a lot of damage to an engine so you need to be sure it can't happen again.

 

[HSSB]

re: Abarth - Earth Lead? [AND coil pack]

Well guys, some good, if surprising news

Just replaced the knackered coil and been out for a nice 15 mile run.. and no gremlin! This included fast B road & town work, and a good 7-8 min sitting at traffic lights for road works idling.

The extra earth lead is back on by the way... Warning heeded

I'm going to take her out and about for a really extended 'normal driving' session tomorrow, but I actually feel quite hopeful - I've not had a clear run of that distance since this thing started.

I have got the warning on startup and symbol for 'engine management system failure' lit, but I think thats because it lit up when I was testing to see which coil had gone (maybe I was clumsy) - is that an 'Examiner' issue to reset do you think, or can garage with a normal fault reader do it? Car actually runs & drives faultlessly now..

edit: I just read another thread - the warnings should then disappear after the car has been driven 3 times? I only started it 3 times and actually drove it once... We'll see later / tomorrow

Anyway, *if* this is a fix, then I honestly do think I've had 2 issues - the earthing problem (which sorting out in itself did not cure the gremlin), and a coil on its way out for a couple of weeks... I can't quite believe it myself, as the symptoms really don't fit, but what other explanation is feasible?

I'll post back with an update after tomorrows extended run but hopefully thats the end of it. Right now can I say a really, really heartfelt THANK YOU to you guys on this thread for the ideas & support over the last few days... You kept me hopeful at several stages when I was close to resorting to a solution involving a box of matches & a petrol can

 

[Argonought]

re: Abarth - Earth Lead? [AND coil pack]

That's a fantastic result if it is sorted (Decks is the petrol head so no doubt he'll be scanning diagrams of the coil-pack to see if it could have caused the 'gremlin' )

Perfect example of how not to lose £1,203 + labour (and presumably still have the same faults )

....but if it doesn't hold we'll still be here for a rethink

 

[Greggers]

re: Abarth - Earth Lead? [AND coil pack]

I've been reading this thread with interest and really felt for you all the way through... I can't help but feel ecstatic if this is now cured with something so simple! Congratulations! (hopefully not premature )

The annoying thing is that apparently, coils which are on the way out don't show up on examiner until you can tell by the way the car is running, that there's a problem anyway...

Really happy for you matey. Now get out there and drive like you've never driven before!

 

[HSSB]

re: Abarth - Earth Lead? [AND coil pack]

Cheers

Well, couldn't wait, so just been out in it 'to get petrol' complete with a bit of an extended detour home again..

Running an absolute dream - no sign of the gremlin at all, though I suspect I'm gonna twitch & go grey at every beep or tick I hear in the car, real or imagined, for the next couple of weeks

Oh, end the engine warning light went off after 3 drives too.

Absolutely ecstatic & very grateful for all the support on here.

Niggles a bit at how a coil could have caused this, but I am not losing any more sleep over it.

About to sit back with a nice cold beer and just relax now...

Cheers & a very, very merry weekend to you all!

 

[Greggers]

re: Abarth - Earth Lead? [AND coil pack]

I suspect I'm gonna twitch & go grey at every beep or tick I hear in the car, real or imagined, for the next couple of weeks

I know what you mean... I felt the same when my odd engagement sensor went on my Selespeed. I keep wondering when the next beep was going to come along...

Talking of failures causing strange behavior, when the engagement sensor threw a wobbly, my foglamp said that it had failed... never happened any other time than when the dreaded auto gearbox failure warning came up... weird...

 

[Andy Monty]

re: Abarth - Earth Lead? [AND coil pack]

BEEP!

just found this thread and it just goes to show something so simple can cause so much grief enjoy your beer