Throttle response

[25chips]

Hello all, this is my first post so please excuse me if I screw anything up. Just cured the unstable idle on MY2000 C2 by following the instructions on one of the threads (cleaned MAF and throttle body). Idles nice and steady now but the throttle response seems to be shot. When I try to blip the gas nothing happens, I have to step on the gas pedal quite a bit to get it to rev. Don't notice this when driving. Just seems like the throttle response became very slow. Afer cleaning the MAF and throttle body I did reset the computer by disconnecting the battery for 5 mins. Any suggestions?

[DeAd-EyE]

i believe it is possible 2 reset the computer by unplugging the battery but i don't know why or if this would cause the dead zone in the throttle. I also have the same problem (and had a battery die on me in autum) but i think it might be something to do with the gas pedal and various cables being loose so that you're not getting proper opening/closing of the throttle.

i don't know if a scan tool will tell you, but if you have one, plug it in and have a look for any anomalies.

[wwest]

You might want to drive it a bit until the ECU re-learns the gas pedal "idle" position.

[DeAd-EyE]

approximatly how long would this take? 30-40 kilometers? is that for E-Gas cars or all 996's?

[1999Porsche911]

It may take a few driving cycles to get the computer properly calibrated.

[FLAT6 jiri]

Hello, I have 996/1998 AT. Every time after disconnecting battery (and it seems erasing ECU) the engine starts behaving oddly. It needs driving at least 300 km in all levels - I mean rpm, throttle positions and gears (approx. 200 miles) to have the real power back. Before it re-learns is the most significant deflection that by pushing full throttle the engine starts to "mute" (I hope it is the right word..) and has much less power then wit pushing the gas just as much as is necessary to accelerate. But after many cycles when I accelerate and brake and so on (really on all gears is necessary - does it have anything with the gearbox too?) it little by little comes back to normal. Does anybody here simmilar experience or should I look for some trouble or wrong setting? Thx

[Loren]

Hello, I have 996/1998 AT. Every time after disconnecting battery (and it seems erasing ECU) the engine starts behaving oddly. It needs driving at least 300 km in all levels - I mean rpm, throttle positions and gears (approx. 200 miles) to have the real power back. Before it re-learns is the most significant deflection that by pushing full throttle the engine starts to "mute" (I hope it is the right word..) and has much less power then wit pushing the gas just as much as is necessary to accelerate. But after many cycles when I accelerate and brake and so on (really on all gears is necessary - does it have anything with the gearbox too?) it little by little comes back to normal. Does anybody here simmilar experience or should I look for some trouble or wrong setting? Thx

That is completely normal. The DME needs to re-learn it's idle and driving pattern.

Why are you disconnecting the battery?

[FLAT6 jiri]

Ok, thanks, I will be less nervous now. I was driving only Subarus before and (I mean STI) there was this learning mode much shorter and not so remarkable.

First time was the battery exhausted (I have bought the car with damaged engine) and second time we needed to remove driver's airbag - and to be honest, I prefere doing it with disconnected battery.

[Loren]

It's just not something you do everyday - that is a good thing.

[logray]

If you follow generic car "obd test drive" procedures I've found the re-learn process is MUCH faster than driving around randomly for a couple hundred miles to accomplish the same thing. The DME has certain conditions to set before it starts behaving like normal. Search official porsche obd test drive on google or something like that.

[FLAT6 jiri]

Perfect. I am going to find it! Thanks

[wvicary]

After battery disconnect if you turn ignition key on but not start the engine for approx 1 minute then key off it will do a basic throttle body adaption which often cures most of these issues.

[logray]

Wouldn't the map get "unlearned" or "erased" once he disconnected the battery?

[wvicary]

Wouldn't the map get "unlearned" or "erased" once he disconnected the battery?

The fuzzy logic used for driver adaption gets lost and most times the throttle body adaption. Leaving the ignition key on after battery disconnect will set the basic idle position/closed throttle plate limits. The readiness check list will still have to met and then the adaption should be complete.

On VW/Audi we need software to force calibrate these limits plus full throttle limits and it checks for circuity faults via redundancy using two potentiometers that read voltage ( one hi volt and one low volt with a equal crossover point ) opposite of each other. The DME in P-cars is very similar.