jahudso2

It could be the pedal assembly or the throttle body. In order to tell which one, hook up a scan tool or your tuner to the OBD port, and look at the PID for Pedal Position %. Key on (engine off), and slowly start pressing down on the gas pedal while you watch the Pedal Position % on the scan tool. If it is reading 80-100% before you get halfway through the pedal, then it is your pedal. If the pedal % increase looks fairly linear with respect to actual pedal position, then your throttle body is probably screwed. JMO

05slpGT

Im not sure if my tuner has the option to look at the pedal position %, i searched all over on it and couldnt find it, i have a SCT xcal 2. FYI i have replaced the throttle body once, the stock one started to throw CEL's after about 10k miles were put on the car and ford replaced it under warranty.

Nuke

It sounds like you're zeroing in on the problem. Keep at it.

05slpGT

This is going to be fun, oreilly and autozone dont have the specific scan tool i need and the local Ford dealerships wants to charge me 105 JUST to have a technician use the scan tool on my car. gawwwdaamn

jahudso2

I have an X-cal 2 and I can see throttle position. If you have a laptop, just download the Livelink program from here - http://www.sctflash.com/showdeviceup...ID=9400&DTYPE=

You can just use a simple USB cable (should have come with your tuner - if you lost it you can get a new one from radioshack or bestbuy) and connect your tuner to your laptop. Then get in your car and hook the tuner to the OBD port, and the laptop to your tuner. Run the software and you should be able to log almost every sensor on the engine.

I don't know why nobody's handheld scan tools are showing you throttle position. It is one of the major PIDs and should show up.

If you have a smart phone, you can also buy a $50 OBD bluetooth adapter from amazon.com and then download the android app "Torque" It is a free app that lets you read PIDs (such a throttle position), datalog, read fault codes, and clear fault codes.

The Livelink software with your tuner is the most powerful tool, but it may take a few hours of tweaking to get it to communicate properly. The configuration settings aren't extremely user friendly, but once it communicates, it is very easy to use.

05slpGT

OK update. I did get the gas pedal/throttle checked. its dead accurate. with the pedal halfway down its right at 50% 75 at 75% and so forth.
So now i want to try to see if its the Throttle Body. I dont have a way to check the voltage of it myself so ill prob have to stop by at a little shop real quick(unless theres an easy cheap way to buy something or do it myself). I have had a throttle body go bad when i had about 10k on the car but i had CEL's popping up, but with this problem i dont have ANY CEL's. ALSO, about a year back i took my car to Les at Quartermile Solutions (for anyone here in houston) and had him check the V on the throttle body and it read a little high, but he said he didnt have a way to lower it, could that be my problem?
It doesnt sound like it would be good for the car, but if i took off the CAI and made a little video of the throttle body opening at 25% 50% and 100% do you think i would notice any kind of difference from just the way it opens? Or is it going to open 100% no matter how much throttle i give it? Or should i not do that and just move on and try to find another solution?

JAMAMAN

No offence, but perhaps the issue is a subjective one and not an objective one ?

05slpGT

Why do you think that?

Norm Peterson

Those are pedal position %, right?

The way I understand it, the pedal position sensor has three separate variable resistances, one of which works in the opposite direction from the other two. But I don't know what would happen if one of the three was faulty in some manner.

You may need to see how the throttle plate moves with respect to pedal motion, not just whether or not it ends up at (say) 50% when you stop the pedal at that point. Does it still follow your foot when you open from 1/4 to 1/2 like it should when you go from 1/4 to 1/2 slowly, or does it "jump ahead of you"? What about between other pedal %?


Norm

Norm Peterson

Overly aggressive tip-in may be fine for the dragstrip, or if you can't stand the feeling that you're might be caught napping at an impromptu street run because the tip-in is too slow. But it's not at all a good thing for autocross, road-racing, or normal street driving, where you really do want nice smooth throttle control from idle all the way to WOT.

In cornering competition, too much throttle too soon = you spin out. On the street it just tosses peoples' heads back and forth until they don't want to ride with you any more.

On one of my other cars, I actually had to slow down the action of a mechanical cable throttle control to make the car as driveable as possible at autocross and just smoother generally.


Norm