Hi All,

Last week I bought my wife a 1996 Brava 1.6 with 55,000 miles on the clock.
It had a faulty injector (number 4 infinite resistance) so I have replaced the whole set and now have 3 good spares.
Before buying the car the owner had spent a fortune on it with a service, new injectors, coil pack etc etc.
I have now just fitted a new gates timing belt kit so it runs smooth and hopefully should be a reliable car (my Volvo T5 is on 225,000 miles so it has a way to go to prove itself LOL)

Anyway, the car runs fine and sounds sweet but when first started when cold if you feather the throttle it revs up reluctantly but if you touch the throttle without being very gentle it hesitates, splutters and even at one point popped inside the manifold
Once the engine is warm it revs up smoothly and is fine.

I know that the ECU system fires the injectors full group when cold and then switches to sequential injection once it has warmed so it seems like the full group firing is over fuelling.
I/She hasn't driven the car yet as the insurance doesn't change over until tomorrow but am just wondering if anyone else has seen this before on the 1.6 engine? My initial instinct is that due to the number 4 injector being dead the long term fuel trims have reached an upper limit and now with 4 injectors firing again and when cold it is massively overfuelling and maybe after a drive the trims will adjust...if not then I will look into it more but it's always useful to get opinions from experienced Fiat owners before making further investigations.

Thanks in advance,
Paul.

what rpm does it idle at on a cold start?

leave the battery disconnected for an hour to reset the ecu.

Hi Jug,

Thanks for your reply.
It idles at around 1100-1200 and everything about the warm up process seems normal, it has recently had a new temp sender.
To be honest I don't know what the revs will sit at when fully warm as it seemed to still be at around 1000 when roughly warmed however I didn't want to leave it running too long as the cambelt had small cracks in it and looked to be already on the border of 'pushing your luck' and I have only just finished replacing this with a new Gates (after finally getting the pulley nut undone which seemed to have been tightened by the hulk on steroids LOL)
I will remove the battery for an hour or so to reset the ECU, I wasn't sure how the Fiat held its self learning settings but it's good to know it is the same as my Volvo where removing the battery will reset the trims etc and hopefully my Elm323 I use will work okay with this ECU as I have a number of diagnostic software that I can try.

Also I'll take the opportunity to thank you and others on this forum for previous advice given to other members as a lot of yours and others advice helped me to work out which model to get for my wife and what things to look out for...so thanks

All the best,
Paul.

i've had an elm323 style interface working on the 1.6 (using uniscan software if i remember correctly) so you should have no problem.

Hi,

Right, I removed the battery negative and left it off for an hour, then started the car and left it tickover for around 6-7 minutes, then shut it off.
Then I took my wife in it for a 40 mile drive, even when fully warm with the temp needle just slightly under the halfway mark the car always ticks over at 1100rpm, never dropping below this, at this revs the car seems be juddering, very much like when pulling away in a car with a warped clutch plate the whole car is mildly shaking.
When trying to accelerate the car seems flat and very hesitant, the more you try to accelerate the less it wants to go, if you back off the throttle is then seems to pull a little better but not like a 1.6 16v should, and every now and then while driving with a constant throttle it suddenly gains a boost of power and lunges forward then backs off again..it actually feels like you have just punched the throttle in a low gear then backed off again.

I will start looking into it once I get some more time but with new plugs, leads, coil pack, timing belt (done by myself and timed correctly) new injectors all of which showed exactly 14.5 Ohms when I tested them and no fault being indicated makes me think it is either an intake leak or a sensor that is not monitored by the ECU (or is out but within the ECU's tolerances)

Jug, the elm323 info is useful, were you able to view real time data and clear fault codes with that?

Thanks,
Paul.

I have the same kind of problem with mine so ill be watching this thread.

I have a thread here : https://www.fiatforum.com/bravo-brava/118636-stuck-ideas-my-bad-idle.html

Hi Reaper,

It must be the colour as my wife's is the same as yours.......forget the fault code reader, I'm getting my compressor out to respray it LOL

Will update this thread if and when I get round to looking into it in more depth.

All the best,
Paul.

a vacuum leak is definately something to check for thoroughly.

check at the injectors and the manifold. use WD40 spray on areas where you suspect a leak (e.g. spray each injector to see if rubber sealing rings have perished). if you notice the rpm suddenly drop when you spray a certain part then you know there is a leak there.

VolvoV70T5 said:

Jug, the elm323 info is useful, were you able to view real time data and clear fault codes with that?

Click to expand...

only used to read and clear fault codes. most universal code readers dont work due to the protocol, which is why you need the right software.

Hi,

Thanks for the info, the old WD40 around the injectors has worked for me many times in the past to diagnose perished injector sealing rings...will try that.
Unfortunately I haven't had the time yet due to working on other cars but as soon as I get chance I will do some investigating and report back.

Cheers,
Paul.

Hi,

Just a quick update, I haven't had chance to work on the wife Brava at all yet however whilst quickly popping out in it the other day suddenly the battery light started flickering on and off, pulled onto a car park to quickly check it and the belt is fine and wiring seems okay so not too worried.
I thougth since I had the bonnet open I'd have a quick look at the piping on the manifold, pulled off the fuel pressure regulator pipe to suck on it and it was broken in half underneath the manifold....so the engine was sucking in air and wasn't regulating the fuel pressure, I have now replaced this pipe and the car is much better but still not right it still holds back if you try to accelerate however now the revs climb much better with light throttle.

The tickover hasn't changed though, start the engine when warm and it sits happily at 800-900 rpm, but if you blip the throttle at all the revs settle down at 1100rpm and never drop below this until the next restart so I still have some investigations to do but definitely worth anyone with similar problems pulling the fuel pressure regulator pipe off at the manifold and checking it as this one had gone rock hard with age and heat and had literally snapped.


Will update again when I next get time.
Paul.

I have actually the same problems with mine bravo. Did anyone find the solution?

Hi,
If it is only doing when cold, then i'd say it was a CTS sensor. It tells the cars computer (ECU) that the car is cold by taking a temp reading from the the water coolant. if cold the ECU will put the car into a cold start mode adding more fuel and raising the rpm. When faulty the sensors will tell the car that its warm even though its cold, hence on initial start up they struggle until warmed up.

also check for split pipes etc.