Hi guys - hoping for a BIG help!!!!

The wife's 2001 1.2 80SX petrol Brava was "juddering" - especially under load. It was occasionally a pain to start, leaving the clock and tripmeter reset to zero, although it would turn over and start eventually.

The judder was similar to a misfire, which if you accelerated from a low speed in 2nd or 3rd, developed a bit of a "backfire" in the exhaust ( sort of one "pop" in the exhaust).

Replaced the plugs and air filter, and put a new battery on it.

Problem remains

Had a mechanic where I work check the car yesterday with his code reader - it listed 3 ecu codes:

P0300 P0302 and U1600

Gone out to it this morning, the damn thing will NOT start. The code light is staying on and it's just turning over. I've got the red key and two blue keys, so I know I can try to recode the keys.

What the hell is wrong with it????? More important - how does someone with limited mechanical knowledge fix it, without spending most of the next 5 years wages at Fiat?

Thanks,
Lee.

Hmm.... P0300 is a general misfire code, P0302 a misfire specific to cylinder 2 and U1600 is an immobiliser error. If you've changed the plugs, suspect a damaged No. 2 sparkplug lead first - I unwittingly broke one changing the sparking plugs and it caused all sorts of grief.
Had a further thought. I've seen an apparently unrelated fault appear after a misfire event before, the ECU wizards told me then it was probably a voltage spike caused by a failing coil or some similar discharge related event.... Could be worth resetting the ECU and then looking at the coil?

Its not going to start because the immobiliser wont let it - the code light should go off. Its probably been corrupted by the poor battery. Replace the battery and check the connections. Have you tried the red key (if there is one ?).

Re: Brava - misfire - the sage continues!!

Thanks for the help up to now - a bit more action on the Brava front today, while I could at least see what I was doing while getting soaked in the Manchester rain!!!

Have today pulled the battery earth clamp off for 50 minutes, to try and reset the ECU. Once it was reconnected, I put the key back in the ignition, and the engine started up OK.

I have since replaced the HT leads, and it SEEMS to be a bit better running, although I've only been able to drive it for 5 minutes!

The continuing problem is this:

Quite often, when I put the key in the ignition and turn the ignition on, the CODE light is still not going out. Sometimes it takes 3 or 4 attempts before it will extinguish. Once it does, the engine will start normally with no fuss.

Where do I need to go next?

Which is No 2 cylinder (the one in the original post that the ECU claimed to have misfired)? Do I count from the coil end, or the offside end?

Can I check the coil for correct operation? What about the ECU?
Is there any way to just scrap the imobiliser altogether?


Thanks for any further help.

Regards,
Lee.


**edit at 2000***
Further follow up - just taken the Wife to her Xmas bash in the Brava and although not as severe - the judder/ misfire IS definitely still there.



Anyone able to suggest where to go next - besides Citroen dealers?????
Coil?
ECU?
Compression test?


Regards,
Lee.