Point of this thread:
The throttle potentiometer is not a serviceable part as it is calibrated from the factory. But if someone wants to have a try this thread will let them know what to expect.
Here we go
So many 1.4 owners seem to be suffering from similar problems at the moment. I found my solution in a replacement Throttle Body.
My symptoms where;
Erratic Idle.
Stalling.
stuttering/light kangarooing.
car acting like it had ran out of petrol.
engine braking while holding a steady pace.
Having to give a little throttle when restarting the car.
Having to give it lots of throttle to stop it misbehaving.
ECU code light comes on. (for the first few days it never came on but gradually came on more)
At first I thought it was a fuelling problem so replaced fuel filter first then the fuel injector second. Both seemed to work but then the problems returned. So i decided to stump up and pay a garage to read the error code. It said Throttle Potentiometer.
The throttle potentiometer detects the throttle angle and from that the ECU decides the right fuel map to run, so if this where faulty you could see every one of those symptoms through the wrong fuel map suddenly being chosen.
The throttle potentiometer is a non-serviceable part, calibrated in the factory. You should never remove it as the Fiat manual states. If it fails you have to buy a new throttle body.
I was tempted to strip it down clean it and have a look inside. By this point I was getting annoyed and just wanted my car reliable, so I did not try it
I had a cunning plan though, as cunning as a fox who's just been appointed Professor of Cunning at Oxford University. Use spray paint to mark where the throttle potentiometer was. This way I could refit it in the factory position.
Bit of masking tape newspaper and old exhaust paint.
Screws out and you can see just how much movement the throttle potentiometer has.
Obviously connected to this is the butterfly valve and on the other end the throttle cable. You can see the spray paint has marked the throttle potentiometer position on the body. Nothing visibly wrong in here, I was expecting oil contamination to be honest after my other problems.
Back of the throttle potentiometer. Nothing obviously wrong to me. You can see where the contacts have worn the tracks. Notice its much heavier ware on the minimum throttle side compared to the maximum throttle side. I presume a new one would not have those marks at all.
<- Min Throttle ---|--- Max Throttle->
I was going to do a test on the throttle potentiometer by powering it with a computer PSU and using a multimeter to test the output when moving the throttle. My problem was so frustratingly intermitent I doubted anything would have been proven and just wanted my car fixed as soon as possible so didnt bother.
Tomorrow If I have time I will try the test.
In summary a very pointless thread with some nice pictures
It might be worth cleaning the contacts if you feel like having a play But! I can not guarantee that spray paint will be accurate enough to refit the throttle potentiometer perfectly.
The throttle potentiometer is not a serviceable part as it is calibrated from the factory. But if someone wants to have a try this thread will let them know what to expect.
Here we go
So many 1.4 owners seem to be suffering from similar problems at the moment. I found my solution in a replacement Throttle Body.
My symptoms where;
Erratic Idle.
Stalling.
stuttering/light kangarooing.
car acting like it had ran out of petrol.
engine braking while holding a steady pace.
Having to give a little throttle when restarting the car.
Having to give it lots of throttle to stop it misbehaving.
ECU code light comes on. (for the first few days it never came on but gradually came on more)
At first I thought it was a fuelling problem so replaced fuel filter first then the fuel injector second. Both seemed to work but then the problems returned. So i decided to stump up and pay a garage to read the error code. It said Throttle Potentiometer.
The throttle potentiometer detects the throttle angle and from that the ECU decides the right fuel map to run, so if this where faulty you could see every one of those symptoms through the wrong fuel map suddenly being chosen.
The throttle potentiometer is a non-serviceable part, calibrated in the factory. You should never remove it as the Fiat manual states. If it fails you have to buy a new throttle body.
I was tempted to strip it down clean it and have a look inside. By this point I was getting annoyed and just wanted my car reliable, so I did not try it
I had a cunning plan though, as cunning as a fox who's just been appointed Professor of Cunning at Oxford University. Use spray paint to mark where the throttle potentiometer was. This way I could refit it in the factory position.
Bit of masking tape newspaper and old exhaust paint.
Screws out and you can see just how much movement the throttle potentiometer has.
Obviously connected to this is the butterfly valve and on the other end the throttle cable. You can see the spray paint has marked the throttle potentiometer position on the body. Nothing visibly wrong in here, I was expecting oil contamination to be honest after my other problems.
Back of the throttle potentiometer. Nothing obviously wrong to me. You can see where the contacts have worn the tracks. Notice its much heavier ware on the minimum throttle side compared to the maximum throttle side. I presume a new one would not have those marks at all.
<- Min Throttle ---|--- Max Throttle->
I was going to do a test on the throttle potentiometer by powering it with a computer PSU and using a multimeter to test the output when moving the throttle. My problem was so frustratingly intermitent I doubted anything would have been proven and just wanted my car fixed as soon as possible so didnt bother.
Tomorrow If I have time I will try the test.
In summary a very pointless thread with some nice pictures
It might be worth cleaning the contacts if you feel like having a play But! I can not guarantee that spray paint will be accurate enough to refit the throttle potentiometer perfectly.
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