Technical Hi everyone, absolute throttlle position issues help please

[snake charmer]

Hi everyone
I don't know if this is the correct way to post a help post, if this is incorrect I apologize.
I have an issue, I have a fiat 500 sport 2009
starts fine open loop, closed loop rough idle sounds from the exhaust as if it is missing, plugged in my elm327 using scanmaster long term fuel trim is -93.8 short term is 86.7, ignition timing advance is -59 absolute throttle position is 88.2, and operating in reverse going from 88 downward toward 40ish when revved,
I have replaced the accelerator and the throttle body I have also tested software on a 500 lounge which was ok and as should be the throttle position starts at 15 going up to 40ish as expected,
can someone please help
kind regards and thanks in advance.
Sid

 

[Ralf S.]

Before we go all digital, let's try analogue.

What's the car actually doing? I think without understanding the symptoms, it's a bit difficult to work out what the diagnostics mean.

I'm guessing.. the car starts fine and idles okay... but when you try to accelerate it's a bit lumpy...?

Does it rev okay after you've passed 1500-1800rpm (i.e. does it only misfire in that rev-range), or is it lumpy/misfiring all the time?



Ralf S.

 

[snake charmer]

Hi Ralh
The car starts fine, as soon as it goes to closed loop
it "SOUNDS" from the exhaust to be hunting/missing No fault codes.
When driving you don't notice any issue if you potter about,
apart from the lack of power to go up a slight incline,
you are forever charging down the gears,
but, if I would say drive normally, it is very noticeable,
it is gutless,
And this is comparing it with
my sister inlaws and two other friends 500 s
you only notice the lack of power, no feeling of a misfire,
I took out the plugs all looks very good.
Thanks for your assistance.
Sid


starts ok then idles a bit lumpy
but when you try to accelerate it cleans it up,
it revs okay after you've passed 1500-1800rpm
it is lumpy/and SOUNDS like it is misfiring, at tickover ONLY
hope this helps