Northern Auto Tech - ECU and Blue & Me Repairs

Technical bravo 1.4s trouble starting when hot

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Technical bravo 1.4s trouble starting when hot

The Sultan said:
infact if you remove the air box you can see wile it's running what the injector spraying looks like loads of pulses of fuel hitting the back of the throttle
maybe you could get it going faulty and have a look in there and see if it is indeed injecting should also here the injector there quite loud

if it is then maybe an air leak that only happens when hot due to expansion or something
Click to expand...

OK - I may be on to something. Last weekend it was VERY cold but I decided I had to get out and give Betsie Brava one last try. It was my intention to check the voltage drop across the injector leads while it was in not-start-when-hot mode.

The engine started fine from cold (as always) and I warmed it up to normal operating temperature. I turned off the engine and it restarted straight away (as always). I then turned it off again and waited for the required 20 minutes to get it into not-start-when-hot mode. Sure enough, it turned over fine but did not fire once. While it was cranking (but not starting) I measured the voltage drop across the injector and it was within 0.2v from the measurement taken when it was stone cold. I then took out the injector, measured the resistance directly across the contacts and replaced it. I thought I’d try to start the engine and it fired up immediately. WOW! Normally the car has to stand for 1.5 to 2 hours before it will restart. I repeated the exercise – ran the engine, switched off, waited for 20 minutes, removed the injector, left the injector in the freezing cold. On replacing the injector the car again started immediately.

I have a theory: when cold the injector works fine. When hot the injector doesn’t work. Starting from cold the injector is cold of course, so works. When the engine is running the injector is cooled by the flow of cold fresh air over it and so keeps working. Turn off the engine and the flow of cold air stops; the injector begins to heat up from the heat rising from the hot engine. After 20 minutes it is hot enough to fail. Remove the injector into the cold air and it cools down. Replace it and the car immediately starts.

The next step is to replace the injector and see what happens. I’ve spent a small fortune on this Fiat and replaced so many parts it’s worth one last try. I’ll post the results.
 
WELL THATS A STEP IN THE RIGHT DIRECTION ! hope it works for you cos maybe thats the thorn in my side,so to speak.i still hav'nt had diagnostic test done,got a fuel filter to put on & ecu temp sensor at the weekend.Fingers crossed yours is an injector-let me know when you try it, ttfn.
 
hello sultan of swing,bit slow to answer you,sorry been busy playing in the snow mate! Have'nt done anymore to car as yet,to nippy to be outside at mo,did replace the therm sensor & fuel filter under that cover with 3 different sized bolts,like the "krypton factor" getting that bit off.lol but never fixed the issue.will look at injector when its not sleeting,snowing,raining,hailing,cats & dogs etc.cheers bud...
 
FUEL INJECTOR - bravo 1.4s trouble starting when hot

Brava 1.4 Hot Starting Problems


Hi, well after a lot of time, effort and money spent on 'Betsie Brava' I've fixed the dreaded Hot-Starting problem. IT WAS THE FUEL INJECTOR.
Following the help and advice I received from members on this site I changed everything there was to change:
Crank position sensor, temperature sensor, oxygen sensor, ECU, ignition coil, fuel pump etc etc.

As a last resort and despite nobody ever having experienced injector problems I decided it was worth paying a last £45 for a replacement injector. The car now starts up every time, hot or cold. I started to think it might be the injector when I took the cover off to look inside, with the engine hot. It was a freezing cold day. Instead of needing an hour or more to cool down the engine fired up. I guessed that the injector was not working when it was hot. When the engine was running the cool air passing over it kept it cool enough to work. When the engine was turned off heat from the engine would rise up the throttle body and the injector would get hot. After being left for just a few minutes the injector was then hot enough to fail. It was then necessary to leave the engine to cool down completely before it would restart. It proved to be difficult tracking down an injector (I live in the Isle of Man) but eventually I found a breaker that did a complete throttle body for £45 delivered.

So, Betsie has been saved from the scrapyard. Many thanks to everyone who offered help. Hopefully my experience will help others who have had the same problems.
martmach1 said:
Hi to all fiat fans,ive got an 96 1.4s bravo,its been brilliant for ages but lately its been hard to start from warmed up.The problems got worse since last week when i put a new thermostat in it,europarts item,ive noticed that the ignition coil gets very hot so i tried to move it away from block.It stays cool now but problem persists!:bang:If it wont start a fiddle with the electrical connector 5 or 6 times putting on and off usually gets it going,is it the coil breaking down as when its cold it starts fine??i changed the therm as the old one was stuck open which made injector light occasionally come on plus heater didnt heat up,this solved the igniter prob! sorry to be long winded but thought it best to explain fully-hope one of you out there can point me in the right direction.Thanks for your time!!!!(y)
Click to expand...
 
Re: FUEL INJECTOR - bravo 1.4s trouble starting when hot

finally got a throttle body from scrap bravo swapped the injector into my car and hey presto it seems to have fixed it!will see if it keeps starting next week.thanks "steviebaby and sultan" and all who put there ideas forward finally it works when hot!!!
 
i'm new here. a friend of mine just got a bravo 1.4 sx 1996.problem is it's not starting, becouse in his attempt to change the ignition coil and HT leads resultet in him messing up and forgetting the posistion of the ht leads, both on the ignition coil and the engine block.
could you please assist, in how to propperly place the ht leads from ignition coil to spark plugs on the engine?:)
 
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