Technical airbag loose,connection,security failure and something bout watter temp (missfire)

[madyotto]

had far to many problems with a fiat stilo 5-6 months ago we had the good old throttle actuator problem sent of for testing and got send back a ok
checked all the norm ect, ect, ect

turned out to be the ecu sending incorrect voltage/current to the 3rd bank on the actuator replaced ecu an so i am here again lol

this time car was brought to me with a misfire so investigated and found that unplugging coil plugs 1 an 4 reading left 2 right made no difference what so ever so jumped to the presumption that coils were down as are well known for going in pairs

2 new coils £113 none genuine article (all the same to me lol )

all fitted misfire still there so curious at this stage swaped 2-3 coils with old ones and yet again car was running on 2 not good

got usb odbII lead and fiatecuscan installed and changed relevent settings everything fine an connected first time

cleared errors disconnected and then when i went to start the engine got these errors (airbag failure, loose connection,security failure and something bout watter temp) and nothing when i turned the key as if to start car
the air bag warrning light is permantly on and is the only light on dash and because what ever is stopping car from starting it is also stopping me from connecting to the diag program

so far i have tried unplug batt for hour no change
i tried unlock an lock from remote as to reset imob still same
disabled pass airbag (with key)same again

sat here for like 3 hours reading old post some seem the same but i have air bag not asr?? failure like other post i saw with the exact same other symptoms that 1 started from a misfire but only on 4 unlike 1 and 4

run out of light so thought i would post and see if you very helpful people could list the things that i should try in your opinions in the order you would advise also any details at to when i test 02 and lambada sensor loom plug and sensor voltage/resistance injectors output from loom and coil outputs from loom and maybe injection and coil plug numbers diagram

i plan on testing
1st injectors
2nd cleaning d4 connectors
3rd double checking all fuses
4th ecu earth


and pending info posted
! injection plug loom voltage
! 02 plug loom voltage
! lambda sensor plug loom voltage

also i need to reset the airbag ecu??? as i understand it by modding the usb wire as in the guide of memory pins 1-3 need connecting by wire has any 1 tryed and how reliable is it as it not my car its me grandads an dont want 2 naff it up

i thank you for any reply / assistance

so it really dose mean

F ix
I t
A gain
T omorrow

lol

 

[Deckchair5]

the air bag warrning light is permantly on and is the only light on dash and because what ever is stopping car from starting it is also stopping me from connecting to the diag program
When dashboard is down to essential items only ie airbag then body computer isn't receiving correct voltage (too low) so I'd check the main power bus ie battery/earths/conections to body computer etc. See Stilo Guide for main battery earth checks and voltage drop tests

Look at your pending codes they're all voltage, voltage, voltage

MISFIRE
you say nothing about the plugs so have you checked them? Misfire can also be injector so that would be the next sep after plugs and then you're into heavy stuff of checking if there is sufficient compressions in cylinders 1 and 4?

AIRBAG ECU
you don't reset this like older Fiats, you fix the fault and then it smiles again.

 

[madyotto]

all errors fix from charging batt still missing on 1and4 reading left 2 right
have run obdII after clearing errors an now it reports no errors so i take it i am down to removeing the injection system and check resistance from each but have u seen it how the fook are u ment to get at them without demolishing engine

it is 1.6 16v outlet at back of engine lol what is wrong
think i will keep my 1.4 8v vaux much better car even tho its l reg lol
what is with the modern car lol

 

[madyotto]

also comp using odbII is saying same pressure from all so we can eliminate this i think
have aslo checked coil and injectors 1 by 1 with no engine just the ignition with odbII and i hear them all what gives
thanks for your reply was helpfull

as a later edit the ecu is sending the signal while engine is running
visual check on the 2 down pots show coil and signal for coil as perfect very strong spark

so it has got to be the fuel i guss
any ideas

 

[Deckchair5]

so i take it i am down to removeing the injection system and check resistance from each
Nooo. Have a look in the STILO guides as I put a description of how to do it there. 10min job

also comp using odbII is saying same pressure from all so we can eliminate this i think
Sorry, what do you mean? engine compression?

as a later edit the ecu is sending the signal while engine is running
to what? coils or injectors?
visual check on the 2 down pots show coil and signal for coil as perfect very strong spark

so it has got to be the fuel i guss
any ideas
Could well be, was it running fine before this? Haven't just had a cambelt change? Anything else related you've done?
You still don't say anything about the plugs or the plug gaps?
Is it misfiring above tickover or only at tickover?

 

[madyotto]

yes sorry spark plugs have been changed kept with ngk the advised gap from another thread

yes i meant engine compression same on all chambers

and i did mean to say plugs all spark very strong on visual test by 1-4 i meant which chambers were not getting fuel i relate to chamber nums reading from 1 to 4 left to right

can you advise if i should check injectors resistance or the wiring first which would you advise

also is there any other connectors that are worth cleaning just in case
thanxs again im now goin to follow fiat tradition and fix it tomorrow unless u could do with me checking to help u help me i wiil do when u reply

 

[Deckchair5]

I would check injector resistances as per Stilo Guide
Then check for signals from ecu to injectors at the same connector

What engine is it?
was it running fine before this? Haven't just had a cambelt change? Anything else related you've done?
What plug gap did you use?
Is it misfiring above tickover or only at tickover?

 

[madyotto]

feels like it missing all the way through rev range i think

also was running perfect not having been touched since ecu replacement after ecu not sending correct signal to the 3rd bank (the 3rd positive connection)on the throttle body socket

all has been fine for the following 4-6 months unitll

my grandad said it started burning oil pritty recently so he put an additive into the oil stop it burning (wouldn't surprise me if he used something he used on tractors 20 years ago pmsl bless him he is used 2 old cars ;( )
he said it stopped useing oil
so yes i am guessing blocked injector but would fiat ecu scan not find this as error
as it reports none after i cleared it this morn
am realy baffled now

 

[madyotto]

and forgot it idles likes any car on 2 sparks out of four lol no sarcasm intended
spark plug gap is 0.9 mm all spark sweet

 

[Deckchair5]

What engine is it?

Ok sounding more and more like fuel or injector problem. Did he put additive in the fuel or in the oil?

Note re injectors
ecu supplies constant 12v to large middle pin at injector multi connector and then supplies earth to each injector to make it open

Can't say whether specific scan tool would spot clogged injector, it should spot seized connector or open or short circuit but partially clogged, bad spray pattern? I don't know

O2 sensor would spot it though and not enjoy neat fuel being sprayed constantly at it with a jammed open injector

 

[madyotto]

am going to test the injects now of the guild
oh its a 1.6 16v on a 53 plate

thanks a lot will post back

 

[madyotto]

NO NO NO NO NO BAD FIAT LOL :bang:
ALL injectors are giving a good 15.8-16.0 from plug

what you rekon next boss
could it be that feelings are right and injectors actually are working mechanically but are clogged hence no fuel i also noticed smell of fuel from bottom of engine before

HELP

thanks once again ur a legand

 

[madyotto]

or should i be asking how to check the ecu is sending the 12v to each injector
relay wouldn't surprise me if it was ecu again ;~(

 

[Deckchair5]

ALL injectors are giving a good 15.8-16.0 from plug
Well that's good, that's means there's no open or short circuit and all injector coils have similar readings

My next step would be to check if the injector earth is being supplied by the ecu. I would use a scope but I think you can check injector signal earth with FiatEcuScan

should i be asking how to check the ecu is sending the 12v to each injector
remember ecu feeds constant 12v to all injectors and supplies signal earth to fire injector

 

[madyotto]

will take a look now mate cheers

 

[madyotto]

nope all i can find on ecu scan was fuel monitoring but that test came back as ok also i hear reley switch when i do manual test on injectors form ecu scan
thanxxx

 

[Deckchair5]

OK let's back up a bit

ENGINE COMPRESSIONS
You say the compressions are fine but you used FiatEcu Scan to check compressions? I'm not that familiar with FiatEcuScan but I'm not sure how it checks compressions. You can compare cylinders using current drawn at starter motor on cranking but i wonder if it's giving a true picture

Grandad put an additive you think in the oil and problems happened immediately afterwards. Stilo has hydraulic (engine oil) valve tappets and needs the correct viscosity oil. If they pump up or stick then you will have no compression

I think I'd do a proper mechanical gauge check of engine compressions

 

[madyotto]

grandad will be down shortly and i will find out if it went in fuel or oil cant understand it if the valves are sticking / stook would it not fire on them cyinders now and then as i havnt ever heard these fire only the two pots that it is running on also plugs are dry

how easy can i check the ecu is sending 12v current to injectors the fact i hear the relay dose this tell me that there is a 12v current or would relay click anyway it at the point where it from my opinion i need to start trying to strip enough of the engine to get at injectors

at this point i suspect that it is the additive in the fuel not oil but he will be here soon will post soon as i no if it was in the fuel i take it i am best to strip engine down an replace injects if they are blocked

also in relation to fiatecuscan it has an off-line mode so i believe so u could look through an remind your self what it can/cant sense if u have the time ect.

am stook now as to what to try next might just go an buy tool to check compression like u said but have u a rough price on how much it would cost (a cheap one as i dont have much money to spend on tool at the moment)

thank you ever so much i would be knackered without your assistance

 

[Deckchair5]

how easy can i check the ecu is sending 12v current to injectors the fact i hear the relay dose this tell me that there is a 12v current or would relay click anyway it at the point where it from my opinion i need to start trying to strip enough of the engine to get at injectors
It's very easy to check for 12v supply as 12v is supplied constantly to the large centre pin at the injector multi connector
But you're still sounding confused. 12v is supplied constantly to the injectors and the ecu gives earth to fire the injectors so it's the earth signal on the dead cylinders you would want to be checking. You know 12v is being supplied as the other injectors are working.

Checking the injectors are being triggered by the ecu can be done in various ways, easiest is by listening with an engineers stethoscope right on it, or you can scope it, or use a light noid which is a low wattage bulb or there are new cheap handheld gadgets which do a bit of both, they listen in and flash an led light when injector is triggered
[nomedia="http://www.youtube.com/watch?v=UrqyrI5aNl0"]YouTube- How To Check Fuel Injectors[/nomedia]

Engine compression gauge is no more than £20 and will last a lifetime, you simply remove the plugs, screw it in and turn the engine over with fuel pump fuse disconnected to stop fuel spraying too. You're looking for vastly different figures between cylinders. Mine had absolutely zero on one cylinder recently and that was a cracked valve

 

[madyotto]

http://www.americantechnology.co.uk/400ml-ametech-engine-restore-oil---german-labelled-can-271-p.asp

this is exact can he used i since found out it was my uncle wayne that oarded it no my grandad phew an it went in oil as is ment to hope this is helpfull for u i have job to do for 1st half of day so reply wont be mega fast
thanx