Technical Brava 1.2 60kW (EU) High idle(1500-3000), idle RPM wildly racing

[Adam Varga]

Hi guys, so here it comes, I own a Fiat Brava 1.2 60kW registration year of 2000 in the EU

It has been a relatively reliable car, but now its givving me trouble. The idle wildly varies and is too high for it to be driveable. On a colder day it idles 1500-2200 racing up and down in a consistent period. On a hotter day it goes straight up to 3000rpm idle also racing up and down.

I have checked the air flow meter and in fact also swapped it out, but no change.

I also got my hands on a diagnostic device with the 3pin connector.

After snooping arround the values it seems the mass air flor sensor gives me relatively constant readings (but it does show higher value than what the "desired" value is), the throttle body seems fine, the opening value does not seem to variate much at all, however the O2 sensor reading wildly varies in sync with the RPM racing. It wildly varies between 870mV and 7.9mV the readout saying Rich/bottom limit sometimes lean(its genuine bosch sensor replaced last year), never really constant. So is the spark timing varying wildly.

I dont really know what else to really do, there are no errors in the ECU, they dont appear even after trying to drive the car like a maniac and I cannot really afford more expensive solutions. This is my only car.

I would assume it is an air leak as the air mass flow meter shows a higher value than what it "calls for" (desired mass air flow is much lower than actual)

Thanks for the help

 

[Adam Varga]

Found the problem. Throtle body position sensor/idle positioner fault. Deemed unfixable. Replacement part unavailable. The problem with these old decrepit cars is that once it breaks its done for cant fix it.

 

[BRAVARulez]

Hi, why dont you look from any scrap yard for any used replacement part. I think this part is used also in alfa romeo's so you might find any used in good condition to do your job.

 

[Adam Varga]

Believe me I really did try. Fiat cars are very rare here and above all that these old crappy cars get scrapped immediately without staying arroundnfor part. So the few parts you can get here are just as worn out or more as the one youre replacing.

I have somewhat fixed this issue, its at least driveable. And put the car up for sale. Make it someone elses problem. I have spent more time and money on the car than it is worth.