Hello, new around here. Tried the boo forums but not managed to get my problem sorted yet.

A few months ago my g/f's N reg 1.4 Bravo every now and again would fail to start up. It would turn and turn, but just not spark and fire up. At first it was say once every week or two where it wouldn't start first time. But it got worse and worse where it was a struggle to get it started at all.

Started off with new plugs, leads, battery and coil pack and it was still not sparking.

We cleaned off all the obvious earth points, connectors etc, but still nothing.

After a few days of getting nowhere looking at it on the drive, we towed it to some where we could get underneath a bit better to look at the phase/cam sensor. Towed it for about 10 minutes, turned the key and it started straight away!

But as we had it over the pit we searched for every earth point we could find, and cleaned them all up anyway. Took the phase/cam sensor out cleaned it up and put it back in.

As it had already started starting, it was hard to say if this made any difference. It worked fine for about a week, then the odd time it wouldnt start. I'd take the key out and try again and again until it started. Eventually, 3 or 4 times of taking the key out it would fire up pretty much straight away!

This has me thinking its either the immobiliser, or the alarm system?

Its a fiat alarm, but an after market/none standard fit one. The alarm unit is in the passenger footwell and theres a separate siren just up from the ECU under the bonnet. Its got a fiat fob with a single button that arms it and also works the central locking.

Wondering if anyone knows how much of and what parts of the alarm system I would need to disconnect to rule it out as the thing causing my starting problems?

Or any other ideas on what I could check?

Trying to figure whats causing it without spending any money really, as its getting on a bit and would probably make more sense to get another than pay for repairs now. Had a mechanic friend looking at it with us a few times, and he's spoken with his auto electrician too, so not doing it completely blind.



But when it does start, it runs completely fine, which is the real bugger.

Cheers

No ideas?

Are you sure its a non spark rather than a non fuel situation.

Cheers

SPD

If there is no spark and no fuel it is most likely a faulty crank sensor. So first I would check for a spark, if no spark I would take the bob off and check fuel is spraying.

If the crank sensor is faulty/not detecting a signal at low rpm the ECU thinks the engine is not turning. So it does not send a spark or fuel, basicly the starter motor is just turning.

Is the orange key code light going out or staying on? as that is the imobiliser. Your alarm is 3rd party by the sound of it. Does the ECU light come on when the car is running?

Fuel came through the one time I checked it. But with it being an intermittent problem, its hard to say if its always coming through?

Checked the spark a few times, and sometimes it doesnt spark, others a weakish orange.

Code light goes off sometimes when it doesnt start, stays on when it doesnt start. Goes off when it does start and even sometimes the code light stays on even when it starts!

On 3 separate occations when its turning and turning and not firing up, I've wound the window down, locked the door and tried again and its fired up. I still think this might be a coincidence, but 3 times is a bit weird.


Now suddenly*, when it turns its sounding like the battery is flat. But when it does finally start, theres no flickering with the head lights when revving/low revs. Waiting to borrow a battery tester so see if the battery is flat, or whether its another symptom.

*first thing in the morning turned and fired up, 10 minute drive, a hour later and battery sounded near flat. Battery is about a month old.

It still sounds like an earth problem to me.

When it doesn't want to play, try the single jump lead.

Cheers

SPD

EDIT: If the battery and earths are ok then -
Sounds like there is a problem with the immobiliser. The orange code light should not stay on and should not be on when you drive.

When you start the car you should turn the engine to MAR wait for the key code light and ECU error light to go out (about 5 seconds) then start the car.

Try your spare blue key. Your not using the red master key are you?


If the spare key does not help other people have had problems with the immobiliser aerial wire. You can see it in the picture a black wire with a loop on the end, it goes arround the ignition barrel and into the immobiliser box.

If your other blue key does not help next I would check the contacts for corrosion. Then try a scrap yard aerial wire.

It is worth noting the cars keys ECU and immobiliser box are a matched set and can not be changed on thier own, unless you get a brand new ECU.

Sorry, single jump lead from where to where?

Cheers.

Thanks Adrian, I will investigate that wire.


And as per your post further up, yes the Alarm is a fiat alarm (the fob has a the fiat logo on anyway) but it didnt come as a standard fit. Whoever had the car before me must have had it put in. When the alarm is going off, the car will not even turn.

Is it possible that the alarm system is interfering somewhere, or is it the immobiliser much more likley?

Kev0 said:

.... yes the Alarm is a fiat alarm (the fob has a the fiat logo on anyway) but it didnt come as a standard fit...

Click to expand...

It might just be a logo on a generic alarm kit to be honest. The alarm could be anything, might have been badly fitted. But since every Bravo has a very good immobiliser as standard it would not make sense to fit a second.

You were right, was just a fiat sticker on the alarm. Managed to disarm it, took the receiver, fuse out and rejoined the wire in the ignition that was cut.

Battery still sounded dead when trying to turn the starter motor. Tested the battery and it isnt flat, although it is 5 amp/hours less than the old battery. Put the new and old batteries on charge anyway, both sound flat. Tested the battery while turning and they doo exactly the sames as what my bravo (oil burner thats working fine) does, 12.somthing, drops that back up to 12.something again.

What would be causing this? Starter motor? Earth? Immobiliser?

And until we sort out the not really flat battery, we wont know if the turning without firing problem is still there or not!

After a few weeks of it working, then it breaking again, then thinking we've fixed it again and so on - this time it seems really dead and the only thing left is the immobiliser or ECU now.

Signals can get from the ECU to the coil pack, but its just not firing up.

Is it possible to disarm the immobiliser, to see if it is that or the actual ECU?
Woudlnt mind running it without the immobiliser if possible. But if the problem is the ECU then I think it will have to go to bravo heaven, which is a shame as when it actually starts up it runs fine!

Grrrrr :bang: