General Throttle acts up

[gradjenn]

I have a panda100hp which has a cone filter. Also the grille has holes drilled into it presumably to increase airflow to the filter.

I bought the car off ebay which was not a good idea!

My problem is that when I accelerate and release the throttle to change gear, the throttle foes not immediately respond and the revs don't drop for a second or two. It feels quite odd.

I wonder if anyone has any idea why this might be?

Thanks

 

[randysbits]

I have a panda100hp which has a cone filter. Also the grille has holes drilled into it presumably to increase airflow to the filter.

I bought the car off ebay which was not a good idea!

My problem is that when I accelerate and release the throttle to change gear, the throttle foes not immediately respond and the revs don't drop for a second or two. It feels quite odd.

I wonder if anyone has any idea why this might be?

Thanks

It, like many cars now, has a fly by wire throttle, sensitivity is not the same as a conventional one with a cable, i would check for safety's sake that your throttle isn't sticking ever so slightly, monitor it very closely and have you engine running when you check it, and give it a few taps using you fingers to ascertain if there is any resistance when returning from opening the throttle.
Doubt there will be a problem, but lets just hope for your sake that its ok and there is no safety issue.

 

[Andy Monty]

you could try a "throttle re learn"


there are two to try

Turn the ignition key to ON position (engine off)
Wait 60 seconds, the time required for the control unit to check the throttle body's internal spring and the butterfly's maximum/minimum angles.
Turn the ignition key to the OFF position
Wait 10 seconds, the time required for the control unit to save the learnt values in EPROM.
__________________



throttle relearn method:

1) switch ignition on (DONT START) for one minute
2) switch ignition off one minute
3) start car (DONT TOUCH THROTTLE AT ALL) and let idle until cooling fan cuts in (10-15mins)
4) switch off
5) repeat step 1
6) repeat step 2

 

[ivantate]

Our idea which has virtually the same engine does this too, it think its a characteristic of the engine and you ca learn to drive around it.

if you change gear when doing a constant speed rather than accelerating it will be far less noticeable. I guess we just lift off a bit before dipping the clutch now.

 

[Most Easterly Pandas]

Our 1.2 Panda with fly by wire developed a similar problem.

Does yours do this when stationary?



Doing the throttle relearn procedure sorted our issue.

 

[Nathan126]

Does yours do this when stationary?

Mine done that once and relearn sorted it for me as well

 

[KozmoNaut]

It, like many cars now, has a fly by wire throttle, sensitivity is not the same as a conventional one with a cable

A drive-by-wire throttle can be just as quick and responsive as a cable throttle, some are slower by design, some by virtue of being cheaply made, but they all have this "lag" built in for emissions reasons.

Right when you lift off the throttle completely is when an engine produces the most emissions, hence the ECU has been programmed to have a slight delay in case you get on the throttle again quickly. This also increases driving smoothness which is much more important to most people than sporty throttle response.

With a diesel you don't feel it as much as diesels (and turbodiesel in particular) have slow throttle response anyway. It's quite a difference switching between my MJ and my bike, which has no gizmos at all, just a direct cable from the throttle to the carbs. Feels great to ride in anger, but the emissions are probably off the scale (no cat either).

 

[LeanMeanRacing]

A drive-by-wire throttle can be just as quick and responsive as a cable throttle, some are slower by design, some by virtue of being cheaply made, but they all have this "lag" built in for emissions reasons.

Another advantage of drive-by-wire is the ability to have two available settings [as on the 100HP; sport and non-sport].

I am driving a Hyundai i20 as well and that holds onto its revs for too long when lifting-off to change gear. As ivantate says, it requires a slightly different method.

 

[Most Easterly Pandas]

Right when you lift off the throttle completely is when an engine produces the most emissions.

Not while in motion. This is why you have fuel shut off at the injectors

 

[KozmoNaut]

Not while in motion. This is why you have fuel shut off at the injectors

The lean condition caused by this is what causes a spike in NO(x) emissions.

 

[lewey]

Doing the throttle relearn procedure sorted our issue.

Did you use the simple wait 60 seconds with ignition on and then after butterfly movement ceases turn off for 10 seconds?

 

[Most Easterly Pandas]

Did you use the simple wait 60 seconds with ignition on and then after butterfly movement ceases turn off for 10 seconds?

Yep

 

[gradjenn]

Thanks for the info - I will try the relearn when I have a chance. Fiat forum is really good.

 

[Geddes]

Another advantage of drive-by-wire is the ability to have two available settings [as on the 100HP; sport and non-sport].

I am driving a Hyundai i20 as well and that holds onto its revs for too long when lifting-off to change gear. As ivantate says, it requires a slightly different method.

Off topic, but the Missus has an i20 and while it feels like drive-by-wire with the revving, when you look under the bonnet there's a physical cable running to the throttle body. Odd.

 

[Most Easterly Pandas]

Off topic, but the Missus has an i20 and while it feels like drive-by-wire with the revving, when you look under the bonnet there's a physical cable running to the throttle body. Odd.

If it's slow on the electrics side like the response of the fuel injectors it will.

 

[R1NGA]

And don't forget that the Idle Control Valve is electronic and it's this that controls the idle on modern ECU cars - not the main TB and butterfly. All down to the emissions control. The same rules that make most diesels miserable to drive sharply away from a junction, as they do their best to minimise smoke by being (very) slow on the throttle, regardless of the approach speed of the truck you need to avoid....

Phil

 

[lewey]

And don't forget that the Idle Control Valve is electronic and it's this that controls the idle on modern ECU cars - not the main TB and butterfly.

Not on fly-by-wire cars which is what this thread concerns. Idle is maintained by the butterfly; why have an idle control valve when the ECU has complete control over the air intake at the butterfly?

 

[LeanMeanRacing]

Off topic, but the Missus has an i20 and while it feels like drive-by-wire with the revving, when you look under the bonnet there's a physical cable running to the throttle body. Odd.

Really? That does surprise me but I've not looked under the bonnet yet. Whether drive-by-wire or throttle cable, I don't like the way that the rpm stays static even when you lift off

 

[R1NGA]

Not on fly-by-wire cars which is what this thread concerns. Idle is maintained by the butterfly; why have an idle control valve when the ECU has complete control over the air intake at the butterfly?

I stand corrected - you are of course right for FBW cars. Was thinking about the setup in my Spider whilst typing that....!

Phil