Technical bravo 1.4s trouble starting when hot

[martmach1]

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!!!!

 

[martmach1]

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!!!!

Well i see that 43 people have looked at my question-however no one seems able to help my problem!! its still doing the same thing,when warmed up turns over but will not start,open bonnet disconnect electrical connector to coil,replace,do a few more times,push new plug leads on coil,jiggle loom above coil(the one with around 14 wires in it)and hey presto it starts! WHY though??

 

[fiat_-_bravo]

It sounds like your Crank positin sensor which feeds info to the ECU on the position of the crankshaft, in short the ECU uses the info to squirt the petrol and fire a spark at the appropriate time.

Does it cut out once it has warmed up?

 

[martmach1]

hi mate just in from work and saw your question.It does'nt cut out-its only if you turn the ignition off that the prob starts,if its warmed up that is.when cold ie a very short trip,switch off and it will re start no probs! its becoming awkward when it needs fuel as it may or may no re start until i fiddle under bonnet?thats a pain so trying to find a way of fixing it.Where is this crank sensor & how would i go about checking it? thanks for your reply mr purple throbber..

 

[fiat_-_bravo]

Carry a pair of pliers in the car with you when it goes again you will need some one with you though remove the HT leads from the sparkplugs keep them apart or you will have them ark! Hold the HT lead with a pair of pliers and get somebody 2 turn the engine over if you get a spark its not your crank sensor

 

[martmach1]

Carry a pair of pliers in the car with you when it goes again you will need some one with you though remove the HT leads from the sparkplugs keep them apart or you will have them ark! Hold the HT lead with a pair of pliers and get somebody 2 turn the engine over if you get a spark its not your crank sensor

thanks mr throb i will try that this weekend,cheers for your help.I will post my results sunday.

 

[fiat_-_bravo]

Make sure you use pliers to hold the HT leads though because you will get a shock even if you hold the plastic insulation

 

[martmach1]

Hi again,ive tried your suggested test mr throb,did it when dark and found no1,no4 no spark.only no2,no3 ok?is that the CPS faulty or the coil pack as noticed a blue pulsing light on one lead/coil end when cranking over so re arranged leads to seperate them which seemed to fix it?also is the cps down by starter motor on gearcase by flywheel wit 3 wires going to it bue,back strip yellow & brown?also has black placky top to it.if not what is that,any ideas mate? thanks for helping! ttfn.

 

[fiat_-_bravo]

Hi again,ive tried your suggested test mr throb,did it when dark and found no1,no4 no spark.only no2,no3 ok?.

I'm still convinced it is your CPS beacuse the firing order is 1-3-4-2 so cylinder 1 fires then cylinder 3, cylinder 4, and cylinder 2. The CPS sends a signal to the ignition to fire number 1 cylinder then the ignition module takes over and fires 3-4-2, So if there is no signal from the CPS number 1 won't fire, and that is why 4 is dead as well I don't know how much mechanical knowledge you have but if you can't understand why number 1 not firing will affect number 4 let me know and I will explain.

is that the CPS faulty or the coil pack as noticed a blue pulsing light on one lead/coil end when cranking over so re arranged leads to seperate them which seemed to fix it?

That sounds like you need a new set of HT leads tbh. Did the ca start when you re-aranged the leads?

also is the cps down by starter motor on gearcase by flywheel wit 3 wires going to it bue,back strip yellow & brown?also has black placky top to it.if not what is that,any ideas mate? thanks for helping! ttfn.

That sounds like your speedo sensor tbh which sits on top of the diff. iirc from when I changed mt speedo sensor it has a blue piece of insulation that does not fully cover the wiring. It's a black cylindrical shape that sticks out the top of the gearbox rite at the back.

 

[martmach1]

I understand what that means with firing order but why would it only play up when warmed up as it starts perfectly when cold?I have fitted new HT LEADS about 2wks ago.When i re arranged the leads it stopped arching.Lastly if it stops raining today i will check out where you say the CPS is,but doubtful its going to stop before it gets dark! when i do get to do it can it be cleaned or is it a throw away part?any ideas? CHEERS FOR HELP ...

 

[The Sultan]

ok i'm thinking cps sensor too as it's a very common fault on that engine

the reasone it will run and then not restart is because the winding in the crank sensor will be more resistant when hot
now when the car is idling at 900 rpm it still produses a good signal for the ecu

howether the starter motor will only turn the engine at 3 or 400 rpm maybe less

not ehouthg to produce a clear signal when the sensor is hot howether when cold it will

this problem if left to go on will eventually stop the car running alltogether

it's on the pulley side of the engine mounted in the casting of the oil pump iirc

 

[martmach1]

helo sultan,do u require me to bow or are you not a real sultan(lol)Thanks for your input,however i stopped at halfords mega store to get a haynes manual and they say its by the flywheel on the 1.4thats also dumb place for it as makes checking the air gap almost impossible!If i get the thing off is there any magic wand trick to test it?i ve been looking at this manual and it just aint getting any better....

 

[fiat_-_bravo]

Yes the CPS is positioned just behind the flywheel bolted to the block.

The Diagram is not very clear but you get an idea of where it is located and how it works.

The first toothed wheel is the flywheel then the 2nd smaller toothed wheel is the wheel the sensor gets its values from which is inside the block



No you can't clean it up or anything and as sultan said it won't get any better only worse and I think they are only around £25 to buy or around £60 if you go to Fiat so you may aswell phone around your local motor factors and just replace it.

If you read at the bottom of the page with the diagram on it tells you what resitance values it should be producing, but you would need a multimeter and tbh it is'nt really going to prove anything.

Hope this helps.

 

[martmach1]

okey dokey sounds like i need one CPS then,i l ring around tomorrow then with luck it will be ok,let all of you know when its done.(with a new one do you put any shims off the old one back on as the depth has to be exact or surely it wont work)??i hate modern cars too many sensors!!! Thanks again to mr throb and mr sultan also...

 

[The Sultan]

the gap is in the manual but it's only for show you will never need to check it

the new and old sensors all bolt rite in no need to check it doesn't actually have to be that accurate i mean look at the tolerance on it

 

[fiat_-_bravo]

:yeahthat:

Sultan is rite you don't need to check the gap. If you read the page it explains why tou dont need to adjust the gap. Although on the next page there is the ideal tolerences that Fiat recomend for the sensor but I wouldn't worry to much about it. I'll post it for you later so you have got it for reference just in case you do need to use

 

[martmach1]

Changed cps sensor or tdc sensor as is called-41squid later the cars warmed up,fan kicks in for a mo,temp just below 1/2way,idling gr8, looks gr8 so turn off leave for 5-10 mins,try to re start,Hey Presto it aint havin it,no fire up! mess with ht leads at coil no1 & no4, unplug electric connector 4 or 5 times & replace then after a few trys It goes.Same problem only my wallets a bit lighter-SO WHATS CAUSING IT!!!!!!!!!!!! over to you the fiat forum.

 

[fiat_-_bravo]

On the plus side u won't need to replace the CPS/TDC sensor anytime soon lol

What plug did you unplug I'm guessing its plug on the coil??

The next time the car won't start just leave it for 5 or 10 mins that will rule out weather or not it is anything to do with everything your jiggiling about.

Does the "CODE" light go out on the dash when the engine starts?

Does the "CODE" light go out on the dash when the engine won't start?

When the engine won't start does you here the starter motor or just a click?

Also this is a long shot but what key are you using the red or the blue key?

Have you noticed if the charge light comes on when the engine is running?



We will get to the bottom of this it will be probably be something stupid

 

[martmach1]

coil leal no1

all interior warning lights work as normal

engine spins over as normal,just wont fire up

no prob with alternator,new batt 3mnths ago,correct one for engine

tried both colour keys,no difference

goning to try scrapyards to get secondhand coilpack if cheap just to see if it works?

 

[fiat_-_bravo]

Yeah probably looking at about £5-10 for a coil pack, or this time of year you will have a big coat on you could slip it into your inside pocket.

Not that I've ever done any thing like that :devil: