VAFC trippin out

[DrLove'sKuDang]

for the past couple days now when im driving and im at wot, the controller throttle% will jump around in the 90's when it SHOULD be at 100%. if i turn the key on but dont start the car and floor it, it does read 100%... and also when i floor it and im in neutral it will read 100%. but as soon as i put it in gear and drive, the percentage reading gets all twitchy.

i think its just a bad reading but its not actually affecting performance. on the way home from work, when i was idling, the throttle read 1-2% eventhough my foot wasnt even on the gas pedal... and it wasnt stuck. my car was idling normally, the controller just happend to read as if i was on the gas. i know the controller was just acting up, cause if i had been on the throttle 2%, my revs would be around 1500... and they werent.

wtf????

[accordztech]

check the connections, though i dont knowmuch about em...

if u get rid of it, i got dibs at 30 bucks

you are just having issues arent you?

[luisitol]

Re: VAFC trippin out

Originally posted by DrLove'sKuDang
for the past couple days now when im driving and im at wot, the controller throttle% will jump around in the 90's when it SHOULD be at 100%. if i turn the key on but dont start the car and floor it, it does read 100%... and also when i floor it and im in neutral it will read 100%. but as soon as i put it in gear and drive, the percentage reading gets all twitchy.

i think its just a bad reading but its not actually affecting performance. on the way home from work, when i was idling, the throttle read 1-2% eventhough my foot wasnt even on the gas pedal... and it wasnt stuck. my car was idling normally, the controller just happend to read as if i was on the gas. i know the controller was just acting up, cause if i had been on the throttle 2%, my revs would be around 1500... and they werent.

wtf????

as far as the 1 or 2% goes your throttle is never fully closed. If your car did not have any air coming in then your car would stall. So the idle reading of 1-2% of throttle eventhough you're not on the gas is correct.

[accordztech]

Re: Re: VAFC trippin out

Originally posted by luisitol
as far as the 1 or 2% goes your throttle is never fully closed. If your car did not have any air coming in then your car would stall. So the idle reading of 1-2% of throttle eventhough you're not on the gas is correct.

so how would the WOT be accounted for?

are you sure at WOT that ur throttle rotor is fully turned?

[timmy0tool]

Originally posted by luisitol
as far as the 1 or 2% goes your throttle is never fully closed. If your car did not have any air coming in then your car would stall. So the idle reading of 1-2% of throttle eventhough you're not on the gas is correct.

the VAFC reads how much you are stepping on it, and not how much air is going through. i understand what you are saying here, but it does cause some concern when it jumps like that. 0% should be read when the gas pedal isn't pressed. DrLove'sKuDang, maybe you have a bad throttle position sensor (TPS) ? just a thought.

[NoSloCB7]

The butterfly on the throttle body is fully closed during idle. The engine gets it's air through bypass ducts in the throttle body. I would check the tps, and its connections

[luisitol]

Originally posted by timmy0tool
the VAFC reads how much you are stepping on it, and not how much air is going through. i understand what you are saying here, but it does cause some concern when it jumps like that. 0% should be read when the gas pedal isn't pressed. DrLove'sKuDang, maybe you have a bad throttle position sensor (TPS) ? just a thought.

the VAFC, just like the SAFC and other piggyback A/F tuning devices, is reading the TPS signal. So you're right its not reading the air going through, you can't measure that in a percentage anyway. What I'm saying is that your TPS will never give a 0% reading. I've seen it already on several DSMs that i've done SAFC installs on. And it makes sense; your gas pedal is connected to the throttle which in turn relays a signal to the TPS then over to the VAFC. If the thorttle is never closed then that means that the gas pedal is never exactly all the way up. As far as we are concerned we aren't pressing the pedal down but what i'm saying is that the travel of the pedal is already calibrated to be at about 2% open when you're not stepping on it.

As far as your WOT problem, the biggest issue I've found on my first installs of piggybacks was not getting the best ground and power source. It'll throw all your readings off and you will definitely get a lower voltage reading from your TPS if you do not have a good ground and power source. If you aren't already i would run those wires right to the battery. If that doesn't fix it then we have to keep troubleshooting

[luisitol]

Originally posted by FushigiRES
The butterfly on the throttle body is fully closed during idle. The engine gets it's air through bypass ducts in the throttle body. I would check the tps, and its connections

I've been explained otherwise, but you might be right.

However I have experienced the 1 or 2% throttle reading on all SAFC equipped cars i have seen or worked on.

[DrLove'sKuDang]

well i know for a fact that reading 1-2% when youre off the gas is not normal.

i figured it could have been a loose connection or maybe stripped wiring on the tps... but why would the tps read differently when im in neutral or when the car is off, when compared to when im in gear.

i can stomp on it in neutral and it will shoot straight to 100%. seconds later, ill put it on gear and floor it... and itll only goto 98%(or some odd number like that)... but rarely 100%