Hello,

I have a 1.2 80 16v 2000 bravo, the battery was dead, charged it overnight, but after charge the engine began to splutter, idling erratically with revs fluctuating and eventually cutting out, was working fine before the battery issue. Changed the battery, continued to do the same. I took it to the local garage to do a diagnostic and they concluded it was the throttle body. Upon exploring the forum I found that others were having similar issues, and most seem to point to the throttle body, so found a guide on the forum which explained how to clean it up, followed it and put it back, was a little better, it didn't cut out but continued to fluctuate, left it on for a good 20 mins.

I found the same TB on ebay and got it, fitted it and initially seemed to settle, it's defiantly much better but still fluctuates, but interestingly the revs do not move from around 800rpm, yet you can clearly hear the engine idling oddly, when it's been driven the revs begin to match the fluctuating idle.

What else could be done to check the idling, could it be a lambda issue?

Thanks for any assistance.

Welcome to the forum tabu.


Check for airleaks between the throttle body and engine head. If there is an air leak the engine rpm can increase above what the ECU wants this is because air is being sucked in uncontrolled. Its a fairly common issue in general.


The 1.2 came with either a cable throttlebody or electronic if you have the electronic version perhaps the pedal end needs looking at but its very rare we hear of people with issues caused by it.

Thanks for your reply, how can I determine if it's sealed properly, is it a case of trial and error, or is there a way of sealing it?

Thanks once again

Visual check of the piping, you could hear hissing. Get a bit of sewing string and see if it is sucked toward anything.

By the by its cable throttle

Thanks will try

I've had another play with it, no signs of air leakage, I've made sure all bolts have washers and tightened them as much as I could, checked the pipes all seem intact. Once it warms up the idle ticks over between 1000 and 1100. What I have noticed inside the car I can hear water rippling or gurgling, it only had water pump and cams done a month back, could the head gasket do this to the idle?

Thanks

Sounds like you have air in the cooling system. You need to bleed it. Make sure your coolant level is up to the necessary marks too.

If this does not cure the gurgling, or only fixes it for a short while you most probably have a coolant leak. I had this issue after each time I flushed and changes the coolant (your water pump change), then when it kept returning traced it to a leaky heater matrix - letting water out & air in.

Thanks, I'll have a go at it, could this be related to my idle issue then?

es you need to bleed the system and try it then,... if water is not reaching the temperature sensors then it could nmess up the ECU signals and behaviour.

The 1.2 is quite easy, run the engine with the heater ON full, then open the bleed screw on the top of the rad, stop when water dribbles out (it should not be brown!). Give all main hoses a good squeeze, then open the black bleed nut on the straigth hose that goes through the bulkhead TO the heater, until water dribbles out. Then do the same for the heater return hose (with the side extension). Top up the coolant but as you will know it is very hard to see the max and min markers and it is easy to overfill.

Obviously the engine needs to be hot enough that the stat is open and water is circulating through the rad.

That's great thanks for the guide, I'll just need to take a look at the Haynes manual to see where the bleed points are as I've never done it before, hopefully I'll get some time over the weekend to attempt this.

just a thought, you did disconnect the battery completely before charging it didn't you?

tabu said:

That's great thanks for the guide, I'll just need to take a look at the Haynes manual to see where the bleed points are as I've never done it before, hopefully I'll get some time over the weekend to attempt this.

Click to expand...

this will give you some hints..,

https://www.fiatforum.com/punto-mk1-guides/43906-bleeding-cooling-system-8v-16v-petrol-engines.html

charlie

Didn't disconnect the battery before charging, the battery has been charged once a year for the past two years, this time was completely dead.

tabu said:

Didn't disconnect the battery before charging

Click to expand...

i would dare say, this seems to me, to be the root of your problems. the charging pulses and voltage spikes from the charger can easily damage the delicate ECU, and seeing as the problem occured straight after, it would seem the most likely cause, rather than messing about with physical pieces which have not previously shown any problems, i would investigate the possibility of a damaged ECU.

paying attention to paragraph 2, sentence 4
http://www.battery-chargers.com/charging_instructions.htm

Right that's interesting didn't realise it could do that, done it many times without issue. So how can I investigate this would I need a diagnostic again, or would that be futile if it's a damaged ecu?

Thanks again

after a little research (im no guru and my post was just a pointer in another possible direction for your search into the problem) the first symptom seems to be engine light staying on, but this seems to be model specific and not guaranteed to be the case on the brava.

im sure someone who knows better than me will correct me if im wrong here, but in theory, it should be as simple as going to a freindly scrappies, finding a runner, and ask politely if you can borrow the ecu for half an hour while you swap and try starting her.
otherwise, a diagnostic will cost more than a new ecu. second hand seems to be about £50 on fleebay

Ok thanks for that, it's good to have an alternative line of investigation should the water drain prove inconclusive, and as you pointed out does seem odd that it began after I tried to charge the battery.
I'll try the drain anyway as don't think it's ever been done so probably could do with it.

Thanks for all your help people, brilliant forum.

Just a quick update, not managed to do anything yet will keep the post updated.

Thanks

Did the coolant drain over the weekend, and still more or less the same maybe a little better but still fluctuates, the gurgling on start up has stop which I'm pleased about, and it seems to be idling at 1100 steadily when warmed up. One thing I've just noticed when taking it for a spin was a hissing when accelerating, I'm wondering if the idle control is sealed properly, sprayed some carb cleaner near to it and no suction, so not sure really.

Guess the next step is too check the ecu, no fault light on dash though, thought I'd keep you posted if interested, hopefully I'll get to the bottom of it.