hi guys.
ive had a little problem with my fiat brava 1.6 100 sx auto brava 2000.
the other day my wife phoned me saying the car kept cutting out and had to leave it on a car park. when i went to look at it it started fine and run great but as soon as it got warm it wouldnt tick over. revs were so low it just cut out so the next day i tryed again from cold it run ok but as the engine got warm the revs got lower and lower then cut out.
if you restart it will run ok if you keep rpm up but just cuts out as soon as you take foot of gas. so read some theads on this forum and suspected the icv so i took it off and cleaned it but no joy so i got a second hand one from scapyard and fitted it still no joy. i also replaced the air temp/pressure sensor still no different ive thought long and hard as to what it can be. ive tested the lambda sensor with a scope and got a nice alternating wave form i tryed removing the rpm sensor to see what happens but car wont start with the rpm sensor missing. ive done a compession test and got a reading of 120 psi on all cylinders the plugs have been cleaned and it appears the all are fireing ok. i ve tested the coolant temp sensor and there is no air leaks in the pipe work. ive tested the injectors got a reading of 14.7 ohms on all 4. the only way i can keep the car running is to tighten the gas pedal cable slightly so it revs at tickover to 1200 rpm. im at a loss now what it can be any ideas when driving it every thing seems great just when you slow down and stop it cuts out.
thank in advance ian.

This may be a totally unrelated fault to the one i had, but it sounds very similar...Same as yours mine started cutting out when warm and was a nighmare in traffic, you say you tested the lambda sensor...how did you do this? as the fault on mine turned out to be the e.c.u not" interpreting" the lambda ceonsor properly,(I found this out by sweet talking the local garage into a free diagnostic plug in) but it is usually only £15 or so anyway.It turns out the new Lambda sensor i had had not been picked up by the e.c.u( Never ever use kwik(Thick) fit) and just needed to be "reprogrammed" ...something to do with unplugging the part and then the battery and letting the ecu pick up the new settings....I am sure someone on here will know Exactly how it its done...Hope this helps xx


***Did you check the leads as well as the plugs?..?

i connected my oscilloscope to the sensor wires i made some leads and then soldered needles to my leads then i stuck them into the isulation on the wires to the sensors i got a signal that resembled a sine wave so i pretty sure it is working ok i then suck one of the leads into the ht cap on each spark plug so i could see a spike on the scope so i think my coils are ok

the only thing my wife said when she told me what happened she said that there was a grinding noise coming from the engine when the fault occured but carnt think what that could be

I will clean whole throttle body from inside first. Then do ECU reset - disconnect battery for 30minutes.

If this not help I would check wires for idle control valve.

i took the old throttle body off and cleaned it thoroughly and it made no difference. i also checked the pot. then i got a secondhand one from the tat yard and cleaned that and checked the pot and stepper motor before refitting. still no different then i pluged the old stepper motor in while enine was running and i could clearly see it moving in and out so im at a loss

one thing that has got me thinking is on numorous acasions when car was healthy there would be smell of petrol inside the car. ( not always just every now and then but when it happened it was quite strong ) i ve looked at the manual and on the car and there is a petrol vapour thingy me jig inside the near side wing could this be my idle problem.

im am also going to test the lambda sensor again as ive been reading some more info and i only tested the sensor when it was at idle.

this problem is really bugging me if i carnt get it sorted it will have to go.

try to reset ECU first

i did a ecu reset first ( left battery off overnight ) but i read on this forum to let it idle for so long to relearn but thats the whole point it wont idle so am i just teaching the ecu the wrong info cuz the only way the car will keep running it to keep the revs up at least 1200 which makes working on it difficult
im very intressesed in finding more info on this petrol vapor thingy any one know anything on this

btw its a automatic is there any sensors on the gearbox that might make the car behave strangly

just a thought where is the ecu on this car
i have one for the auto box under back seat
and there is one in the engine conpartment
is there any others

winnywood said:

the only thing my wife said when she told me what happened she said that there was a grinding noise coming from the engine when the fault occured but carnt think what that could be

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Tensioner, recheck the cam timing.

Cheers

SPD

Hey hope this helps with the search for your ECU

hi all had a very frustrating day messing with brava and not knowing.
today i removed lambda sensor to look at it. it looked clean not sooty
i thought it could be my coils as engine sound very lumpy when ticking over so i got a spare one from scapyard and a new temp sensor so fitted them and did a ecu reset. again ran engine and all was fine then as she got warm idle was lumpy but didnt cut out so took her for a spin but as soon as i got home again she cut out and then wouldnt idle i took ht leads of ( as lumpyness sound like misfiring ) and tested the resistance of each lead i wa a bit suprised by results.
( longest lead 0.978 k ohm )
(2nd lead 1.4 k ohm )
(3rd lead 1.9 k ohm )
(smallest lead 1.2 k ohm)

bit strange i thought

also i been reading some info on compression tests and this website says a 10.5 - 1 engine should be about 200psi on cylinders but i only get 120 psi. http://www.vauxhallownersnetwork.co.uk/showthread.php?71683-How-to-compression-test-a-petrol-engine


i decieded then to adds some injector cleaning fluid to petrol and take here for a thrash and the car went like poo of a stick. she had no probs get to 100 mph and acelerates like a beut.
so could my timing belt have slipped say one toooth? i thought that would show up on giving it some stick.

this sound simlar.
https://www.fiatforum.com/bravo-brava/133502-brava-1-6-cam-timing-tools.html

so ithink i will try some new leads also a new lambda sensor.
i seen a lambda sensor at scrappers today but it was from a 1.2 brava and the lead is not long enought so if i lenghten leads will it work ok.

zazadavison said:

Hey hope this helps with the search for your ECU

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thanks for that i know where the one in engine bay is i was asking if there were any inside car like behind dash

Do you get any lights on your dash when the problem is there? Does the injector light come on when you switch the ignition on and then go off i.e. is the light working? I would check the resistance of your injectors when it is warmed up if poss. Your HT leads, I think are fine as is your coil. The leads are of a silicon conductor type and will show a resistance from the 9V a tester can supply for resistance checks.

maximoke said:

Do you get any lights on your dash when the problem is there? Does the injector light come on when you switch the ignition on and then go off i.e. is the light working?

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no i dont get any lights on when the engine is running.

lights are confirmed as working as the come on when ignition is on but go out shortly afterwards.

there is two lights one that looks like a injector and one that looks like a box with a line coming from it.
i think that is the gearbox light.

im not so sure as to the reading on compession test as im going to test it on another sorce to see if it is reading correct.

in my earlier post i questioned the fuel vapor thingy me bob is there any posibillity that this could be faulty as in the manual it says that the ecu switches this thing on when the engine get up to temp.

this problem it doing my head in :bang:

hi , I dont think it is fuel vapour selenoid valve. Normally it is not open in idle. ECU just open it when try to add more fuel in mixture. I will idle higher if it is something wrong with fuel wapour selenoid.

Try to disconect connector for idle control valve and start engine. If it runs then it is obvously something with wires for idle valve.

If i does not work, I would try to disconnect cable for throttle position sensor, and start engine.

fiat37 said:

Try to disconect connector for idle control valve and start engine. If it runs then it is obvously something with wires for idle valve.

If i does not work, I would try to disconnect cable for throttle position sensor, and start engine.

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should i do this when engine is warm?

i took my compression tester to work today to test it and it was faulty. ( rear of neddle on gauge was geting caught on screw that holds face plate on )
re did test when got home (cold engine) it now reads 210 psi on all 4 pots so no burnt or sticky valves.

could this be a problem with my cat?

does not matter, just disconect connector, engine should start but you will have red light inside, idle control does not work and everything else works

if you disconnect throttle sensor, ECU calculates data depending on pressure sensor



i reccomend you to look if your engine is in a correct phase, you said that compression test was not ok at first, so cam belt could jump over a tooth. this could cause idle problems.

I doubt it is cat. But also block in exaust system could cause that problems. Take a look at cam-belt and sensors and idle valve first

fiat37 said:

i reccomend you to look if your engine is in a correct phase, you said that compression test was not ok at first, so cam belt could jump over a tooth. this could cause idle problems.

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how do you mean in correct phase

compression test says ok 210 psi in all 4 clyinders ( tester wasnt workin correctly before )

if timing belt has jumped wouldnt it be rough at higher speed

how can i tell if the belt has jumped as it looks ok and is tight is the any timing marks on cam sprokets?

tried disconnecting idle valve and starting
car starts but only with foot on gas pedal no pedal no start
so i guess the icv is ok

how can i check valve timing?

its special tool to lock cams and no.1 must be at 0 degrees