I was told that this was usual, but I decided just to double check... and it's one of those things that I searched but didn't really come up with any answers.

This only happens in first and second - but basically the moment I let off the gas the car jerks and basically stops immediately. It sucks if you're trying to just kick around a parking lot because you can't stay in gear. It does it a little in 2nd, but not really in any other gear. Is this normal or was the last owner a bit more rough than he should have been?

 

i have the same thing on my truck.

 

You need to adjust your throttle position sensor. Do you have an S4 or S5 car?

 

I second nonameo. You need to set your TPS. It's not hard, and it will get rid of most of the jerking on decel.

 

Had the same problem no less than a week ago.

Was an easy fix.

Whip out that multi-meter and check that TPS!

 

It's an S4 - I followed the proceedures I got from fc3spro and I got a blowout (jump up to 6K in resistance) so I figure this thing is jacked. Time to junk yard hunting or is there something that I can do to fix this? I know that the S4 has only the short range so I only have action up to 15% throttle.

 

i have an s4 tps i can sell. make sure that's the problem first. feel free to PM me as i may not check replies on this thread.

 

Does anybody have an explanation as to why it really only happens in first gear? And less so in ever gear above?

 

there's also something (damn i cant remember the name!) that mazdaspeed7 told me about that FCs have. its "start something bucking" i wanna say. he said it had to do with fuel delivery. he even said its common in such situations are parking lots. we were discussing it while he was explaining porting on my car (dos and donts). if i remember the name, i'll post it. i knew exactly what he was talking about though. "bucking" was exactly how i'd explain it.

 

yeah, bucking is basically the best way to explain it I guess. Could it be like a mount or something that's broke all to hell or is it something even bigger than the sensor?

 

Sounds like the TPS needs to be tuned, but it could be something else. I had similar problems caused by the water thermo sensor. Is the ECU throwing any codes at you?

 

it was explained to me as a tuning issue common in FCs. using a standalone, he got rid of the bucking. i can't guarantee thats your problem nor can i validate the info, but i have found him to be a good source and believe his word. i'm sure a properly running TPS could only help, though.