Technical Weird throttle delay

[SGThirkell]

Hi all,
After renewing/replacing ECU and starting to get my car running properly, I now notice a delay whenever I put my foot on or off the throttle, only fraction of a second but enough to feel weird when driving, especially when trying to slow down and it keeps going momentarily!
I cleaned the throttle (twice) just to make sure. This made idling ace but the "delay" is still there when driving.
Any ideas as it's doing my head in :bang:

EDIT: Actually it's more pronounced on releasing the pedal (sorry)

 

[Clivvy]

throttle position sensor issue? with the ECU being changed, maybe you need to do some sort of adjustment type thing, like doing a proxy alignment...

 

[SGThirkell]

throttle position sensor issue? with the ECU being changed, maybe you need to do some sort of adjustment type thing, like doing a proxy alignment...

I don't know. I'm not getting any faults when I scan though. Also what is a proxy alignment (sorry I'm new to this car)

 

[mhowse]

No harm in trying a throttle body relearn..details in link below

https://www.fiatforum.com/newbie-central/292687-throttle-body-relearn.html

 

[Clivvy]

No harm in trying a throttle body relearn..details in link below

https://www.fiatforum.com/newbie-central/292687-throttle-body-relearn.html

that's the one!

 

[mhowse]

that's the one!

Having one of my better days .....Normal service will resume shortly...:bang:

 

[SGThirkell]

No harm in trying a throttle body relearn..details in link below

https://www.fiatforum.com/newbie-central/292687-throttle-body-relearn.html

So this will stop the delay on releasing the pedal?
Does this relearn rely on the engine having to be cold so it does idle for 10-15 then or will doing it on, say, a part-warm engine (maybe 5 mins idle till fan) still work?
Also is this on-off thing at beginning and end tell it to start and stop the learning procedure, is that why you do that?

Cheers

 

[mhowse]

may or may not fix your problem with throttle..just something to try as you have been looking into the throttle body and fitted different ecu, so certainly no harm in giving it a go.
Never needed to use the learn procedure myself so can offer no further help, would think that so long as you do it till fan comes to life it would be ok, if not try it again in morning or when ever engine is cold..and can only guess that the switch on switch off part is as you say part of the ecu knowing to go into learn mode...either way nothing to loose by giving it a try..hope it helps with your fix.

 

[SGThirkell]

may or may not fix your problem with throttle..just something to try as you have been looking into the throttle body and fitted different ecu, so certainly no harm in giving it a go.
Never needed to use the learn procedure myself so can offer no further help, would think that so long as you do it till fan comes to life it would be ok, if not try it again in morning or when ever engine is cold..and can only guess that the switch on switch off part is as you say part of the ecu knowing to go into learn mode...either way nothing to loose by giving it a try..hope it helps with your fix.

Hi, done the throttle relearn and still the same unfortunately
It's annoying as I seem to have cracked everything else that was wrong and it runs sweet now apart from this.

 

[mhowse]

Least it is something tried pity not work for you...do you have any diagnostic software such as multiscan to plug in ..may give an idea which area to look into.

 

[SGThirkell]

Least it is something tried pity not work for you...do you have any diagnostic software such as multiscan to plug in ..may give an idea which area to look into.

Yeah, I have FiatEcuScan so that will be next port of call I think. I'm going to look at the pedal position and throttle position graph while I rev up and release, see what that shows

 

[mhowse]

was thinking you may be worth looking at connectors for throttle and throttle pedal, as the pedal is potentiometer type, does it do when you are parked in neutral and gently rev the engine see if the first gentle press of pedal gives no response to the engine, still not much help in knowing what is causing it, and not want to go changing parts you not want to like the throttle pedal workings.

 

[SGThirkell]

was thinking you may be worth looking at connectors for throttle and throttle pedal, as the pedal is potentiometer type, does it do when you are parked in neutral and gently rev the engine see if the first gentle press of pedal gives no response to the engine, still not much help in knowing what is causing it, and not want to go changing parts you not want to like the throttle pedal workings.

I'll try that first gentle press bit tomorrow when I hook up the laptop as I've not took any notice but yes, it still does the main "hanging on to revs" bit when parked and in neutral

 

[SGThirkell]

Well, not the best example but shows what happens parked up and slightly revving. Not bad response from pressing pedal but delay after releasing is about 1.5 seconds average. Any ideas what this is caused by anyone?

 

[mhowse]

was this delay there before you changed the ecu..

just thoughts but possible problem with throttle inlet, maybe servo of the throttle valve not functioning as should, have you had a read of the guide relating to cleaning the throttle valve in link below, post30 of the guide mentions possible damage to servo if cleaning without engine running, not saying this is your problem just an idea as something sticking and holding the throttle for a brief moment .but only way to check would be to try another throttle inlet.or try and see how it functions when running if possible.guess could also be delay from throttle pedal, would check connectors all tight and clean before spending on parts but all that comes to mind for myself.

https://www.fiatforum.com/stilo-guides/83260-cleaning-your-inlet-control-valve.html
check on post Number 30 of the link