hey,
i've been experiencing some problems with my stilo over last few weeks, tried investigating myself, didnt help, went to fiat today, didnt solve much either....
the symptoms are the car going into limp mode(and out of it) whenever it's suited, when driving and pressing accelerator the revs start dropping and it just doesnt respont if you push any more, but comes back to life once released and pressed again and sometimes when stationary reving it up and holding revs at same level(lets say 3k rpm) it starts choking and revs go down the back up then down untill it becomes irresponsive to accelerator being pushed untill you release it...
the fault codes were: P1221 and P1222 or it might be P1121 and P1122, not sure witch way round, but one of them is throttle body position sensor fault and the other one is actuator position sensor fault.
fiat guys told me it would be much cheaper finding car electricians to have a look at it, so i went down to one garage on a way home and he said it's most likely be some stupid sensor knocked out, not the throttle body going nor ECU...
i forgot to mention that i sort of ruled out throttle body as i've swapped it over with my mates, he's got same engine as me, then i've checked the coils witch was the first guess and took accelerator pedal out and it didnt seem to have any faults in it...:bang:
can it be that there is a clog somewhere in the fuel injection system that causes all this??? gonna book my car in for a fuel filter change in next day or two...
any thoughts or help would be much appreciated:worship:

1.6 engine?

[FONT=&quot]It will be these
P1121 Throttle Position (TP) Sensor Circuit Intermittent High Voltage
P1122 Throttle Position (TP) Sensor Circuit Intermittent Low Voltage
which means there is a fault in the wiring or power supply from the ECU to the throttle body
[/FONT]
1.6 wiring diag

The fact you've changed the throttle body with no effect points even more to wiring or power/ earth supply voltages for which the ECU is responsible

fiat guys told me it would be much cheaper finding car electricians to have a look at it
Dearie me, don't they have electricians at Fiat garages any more?

can it be that there is a clog somewhere in the fuel injection system that causes all this???
No, like your car is telling you, it's a throttle body to ECU circuit problem

idd it's a 1.6 and that was one of the solutions made in the examiner, but it was actually saying to check power/earth for the injection power supply... that diagram is not saying alot to me tbh, i've got it booked in tommorow for a checkup, will mention that to them and hopefully they will find something... i'll ask them to have a mooch with the all the wires... any particular places to look at?
thanks guys

well back from the garage with not so bright news, but still some... the bloke over there said that he's nearly 100% sure that it's the pedal, so i've ordered one and hoping to change it over on saturday, will let you know how it ends up

got a new accelerator pedal, witch didnt help at all, so had a good messin with the wires yesterday and it all came back to life! even engine managment light went off, up untill this morning...
got a new symptom tho... when accelerating the car starts to struggle and sort of dies, obviously as it's moving and in gear it doest die, but all the beeping starts as it was just turned on and the weirdest one is that the temp gauge goes right up to the red flashes the message that temperature is too high, then goes down... it also struggles to iddle, just drops down to 500rpm and jumps back to ~1k for a few seconds, then back again

Deckchair5 said:

fiat guys told me it would be much cheaper finding car electricians to have a look at it.]Dearie me, don't they have electricians at Fiat garages any more?

Click to expand...

who said that...that's what DET were (supposed) to be for?

Simple 5 min test will determine if it's ECU

That's what i thought

Well look, your garage friend said he was almost 100% it was the acclerator pedal but your car is telling you it is almost 100% sure that it isn't the accelerator pedal. Who are you going to believe next time?

I'd home in on the circuit shown above between the ECU and the throttle body valve exactly as your car and we said before

Temp gauge going straight into red and back again is often bad earth either at the ECU or the main battery to engine earth but can also be an ECU voltage supply drop out

Things you can try
Remove the throttle body and ECU connctors, inspect for bent pins or pins lower than the rest. Clean with contact cleaner (nothing else) .

Try wiggling the throttle body connector with engine running and see if that produces the fault.
It really needs some electrical testing of that area
is steady 5v and earth arriving at throttle body pos sensors?
Are throttle body position sensor return signals plausible?
Do you have aircon and do you have any problems with that?
What fault codes are coming up now?

well i had a good conversation today with one of the car electricians with actually agreed to all what i've said and actually said some things same as you deck, instead of trying to tell me that it needs to be diagnosed again... obviously that is just money making rules(well not only, but i know what the faults are already, i just want them to be fixed!) instead of thinking what might cause it and so forth, so i will be ringin him first thing in the morning to see whether he would take the job and hopefully complete it
will have to worry about the other bits when this is sorted, unless i wont need to

well it was a bloody ecu, after a week without the car, but it's now sorted and runnin perfect with new ecu and hefty £366 bill:bang: well it's only money, will have to make some more

x3me said:

well it was a bloody ecu, after a week without the car, but it's now sorted and runnin perfect with new ecu and hefty £366 bill:bang: well it's only money, will have to make some more

Click to expand...

Normally is and there is a good reason for it that was discussed a few years back. Anyway glad it is fixed

hello x3me,
looking at your story is like having flashback from my last week i have 1.6 stilo 2002 3dr and same throttle problem, I want to check throttle body it self but if its ECU like in your case please can you let me know what was wrong with it and where did you sort it out as im from manchester aswell and im desperate to get my stagecoach back on track as im expecting junior within next 2 weeks and prefer tu use own transport unit to pick him up fro hosp.