Technical 1.2 8v Grande Punto no start

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Technical 1.2 8v Grande Punto no start

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My daughters 2008 GP displays all the symptoms in similar posts so I booked a day off to check the battery and clean up all earthing points. Battery was original so installed a new one, removed all engine bay earth points and fuse box, cleaned the terminals and posts - refitted and protected with petroleum jelly / hmp grease as required. All seemed well and I at least got the car started (thought it may have originally been the starter motor), however the "clicking" noise from the top of the engine has returned and it appears to be coming through one of the relays loudest - so swapped relays, didn't work, the noise remains and sounds like the injectors or fuel pump is trying to reset. When it does start it runs really "rich" and shuts off after a couple of minutes. I am getting a combination of dash warning lights, ranging from all of them with the temp gauge going up and down to just the steering light on, but when the car does start all appears normal, I have also tried using a different key with no success. I have checked the wiring to and from various sensors all to no avail. Can anyone help please, I have got this far being guided by the really useful posts on this site but short of spending the big bucks on a replacement engine management system or sensors I am at a loss!
 
My daughters 2008 GP displays all the symptoms in similar posts so I booked a day off to check the battery and clean up all earthing points. Battery was original so installed a new one, removed all engine bay earth points and fuse box, cleaned the terminals and posts - refitted and protected with petroleum jelly / hmp grease as required. All seemed well and I at least got the car started (thought it may have originally been the starter motor), however the "clicking" noise from the top of the engine has returned and it appears to be coming through one of the relays loudest - so swapped relays, didn't work, the noise remains and sounds like the injectors or fuel pump is trying to reset. When it does start it runs really "rich" and shuts off after a couple of minutes. I am getting a combination of dash warning lights, ranging from all of them with the temp gauge going up and down to just the steering light on, but when the car does start all appears normal, I have also tried using a different key with no success. I have checked the wiring to and from various sensors all to no avail. Can anyone help please, I have got this far being guided by the really useful posts on this site but short of spending the big bucks on a replacement engine management system or sensors I am at a loss!
Just had a mobile auto electrician run diagnostic scans but there is an "unable to communicate with the ECU" message which, he points out could mean a new ECU and remap. He did get 8 error codes all together in the antilock brakes, airbag, body computer, power steering and instrument panel systems. So at the moment the car (2008, full years MOT, 36800 miles) is a non runner. As a new ECU looks like being a non cost effective option, it looks as though the car will be scrapped / sold off for spares unless anyone on the forum can recommend next steps or put me in touch with a reasonable parts supplier?
 
Just had a mobile auto electrician run diagnostic scans but there is an "unable to communicate with the ECU" message which, he points out could mean a new ECU and remap. He did get 8 error codes all together in the antilock brakes, airbag, body computer, power steering and instrument panel systems. So at the moment the car (2008, full years MOT, 36800 miles) is a non runner. As a new ECU looks like being a non cost effective option, it looks as though the car will be scrapped / sold off for spares unless anyone on the forum can recommend next steps or put me in touch with a reasonable parts supplier?
Update - I sent the ECU off to "ECU Doctor" for further diagnostic testing, they were very helpful and kept me updated but low and behold the ECU was ok with just a couple of error codes on the system for starter relay and crankshaft sensor. I have read most of the posts about electrical gremlins and starter issues on GPs so was hopeful that replacing the crankshaft sensor and 2 red relays in the engine fuse box would solve the issue - unfortunately not! Last resort was to try and bump start but this did not work. So, to recap I have replaced the battery for a brand new higher capacity one, followed all the posts about poor earthing, tested earthing continuity ( all ok) and used jump leads to provide additional earthing, all fuses (engine bay and glovebox) tested ok. Not sure where to go now having laboriously eliminated all known electrical issues on the forum - any other suggestions will be most welcome!
 
I recently bought a reconditioned starter for my daughter's car for no good reason! Like you, I had checked and re-checked the earth cable studs and they were fine. I put a jupm lead from the battery negative to the engine block (still no start). It was only when I put a SECOND jump lead from the battery negative (leaving the first one on) to the earth stud on the BODY that the car started.

In deperation, I went to take the whole earth cable off the car to examine it more closely. In doing so, I tugged on the bottom half of it (where it passes through the crimped terminal holding it to the chassis leg, about half way down its length, and it just came apart in my hand! Under the heat shrink insulation the copper had corroded / fatigued away to green powder!

A £4.99 ready-made earth strap ffrom Halfords fixed the problem completely. I now have the top half of the original earth lead going from the battery to the stud on the chassis leg and then the Halfords one from the stud on the battery leg to the gearbox.
 
Thanks Avocet, looks like a full strip down is required of the earth cable again although I will give the jump lead test another go as you have described. I am getting crazy voltage readings from the car, e.g. Pin 16 on the OBD socket is reading between 22 and 26 volts! I still can't communicate with the car via the OBD scanner which would suggest earthing problems! Oh well back to basics again - will keep you updated on progress
 
I didn't get any joy with the jump leads to create a temporary earth so carried on stripping down and removed the fusebox, attached picture looks the culprit though it didn't disintegrate it is clearly only connecting by s few strands!
 

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I didn't get any joy with the jump leads to create a temporary earth so carried on stripping down and removed the fusebox, attached picture looks the culprit though it didn't disintegrate it is clearly only connecting by s few strands!
Update - problem solved! Replaced the single earth lead with 2 cables from Halfords. Upon rebuilding the electrics I noticed some green dust from the bottom of one of the 3 block connectors that push into the underside of the fuse box. I clipped off the top of the connector block and sure enough there were 2 cables "hanging by a thread" - I spliced in new cable after cutting out the rot and the car started first time, all the warning lights have gone out and the car drives fine now. Shame that Fiat went for sub standard Romanian copper cables but after a few days on this the car is a decent runner again, thanks to all posters re: electric gremlins. Don't get caught out by so called professionals who recommend expensive replacement parts, you just need to be methodical, following the guides on this forum and be really forensic when inspecting cables and wires where an electrical problem is diagnosed.
 
Result! Yes, it's amazing how many "box changers" there are in the motor trade. Good old-fashioned diagnosis is a dying art! In fairness to Fiat, I think the copper wires are probably OK, but the fue box is poorly designed. It's located right under the edge of the bonnet, so it's asking for water to leak on to it, and the bonnet release cable can prevent the correct fitting of the lid, which then won't seal all the way round and let water in.
 
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