Give a girl a brake and help her out? ;)

pinkgyrl · 09-24-2009, 07:18 AM

Any help appreciated.

I have a 1998 stock Supra; I purchased it in 1998, and I've been the only owner. It's never had any mechanical problems except for last year when the heater stopped getting hot (hehe...so many bad pun opportunities here...grin)

The "check engine" light came on last week. When you push the gas down nothing happens until you push it to the floor, and then it will accelerate. Every once in awhile, it will "jump" back into normal driving mode and be fine for an acceleration. It's had a diagnostic, which my apologies - I am not a mechanic, the first showed a failed thermostat (it's been replaced) and the second code indicated that the throttle sensor was bad - this has also been replaced now after waiting 3 days for the part. After these two parts were replaced, the car ran fine on the test drive. After it ran and then sat for awhile, the same problem started all over again. Any ideas at all? My roommate works a repair shop, but he hardly has any free time during the day to spend on it - so, I'm stranded currently.

Thanks for reading!
Wendy

Krem · 09-25-2009, 07:36 PM

Do you have a manual or auto? Doubt the tranny is the problem, but if your acceleration is poor because the gears aren't shifting on an automatic, it could be a possibility.

I was thinking Throttle Position Sensor the whole time reading your description, but you mentioned you replaced it... when you lower the gas, does the engine rev up higher and higher but your speed remains constant until it's Full Open Throttle? or do your RPMs remain low until you get FOT and then you also get acceleration? If your rpms climb but the car doesn't accelerate, I'd be willing to blame the transmission.. if you don't build any rpms until you're FOT, then it could be the throttle position sensor still (could have been installed incorrectly?) or probably something in the fuel system... either the injectors or filter are clogged up... when you push the pedal down enough, you're pushing enough gas to get past the clog... but not until then..

Dunno, kinda shootin darts in the dark... I'm a computer guy, not a mechanic... but knowing how the systems work (in generalized detail) has drawn me to these conclusions... if someone more mechanically enclined has other advice, I'd strongly suggest taking theirs over mine.

pinkgyrl · 09-27-2009, 04:19 AM

Quote:

Originally Posted by Krem

Do you have a manual or auto? Doubt the tranny is the problem, but if your acceleration is poor because the gears aren't shifting on an automatic, it could be a possibility.

I was thinking Throttle Position Sensor the whole time reading your description, but you mentioned you replaced it... when you lower the gas, does the engine rev up higher and higher but your speed remains constant until it's Full Open Throttle? or do your RPMs remain low until you get FOT and then you also get acceleration? If your rpms climb but the car doesn't accelerate, I'd be willing to blame the transmission.. if you don't build any rpms until you're FOT, then it could be the throttle position sensor still (could have been installed incorrectly?) or probably something in the fuel system... either the injectors or filter are clogged up... when you push the pedal down enough, you're pushing enough gas to get past the clog... but not until then..

Dunno, kinda shootin darts in the dark... I'm a computer guy, not a mechanic... but knowing how the systems work (in generalized detail) has drawn me to these conclusions... if someone more mechanically enclined has other advice, I'd strongly suggest taking theirs over mine.

Hi - thanks for the response! I have an automatic (grr...I ordered a manual and after waiting 3 months and the automatic arrived at the dealership, I was told to take it or I wouldn't have another chance - since I live in crappy Arkansas...I believed them...hehe!).

The RPM's remain low until FOT and then the acceleration kicks back in - the code that keeps coming up is the Throttle Position Sensor, so they went back in and checked it again, and it's installed correctly. They tried a new diagnostic machine, and it appears that there may be something lodged in the throttle body itself.

Thanks so much for the insight! I've learned more this week than I ever wanted to (hehe) Hopefully, it will be repaired soon - because this girl is tired of being stranded!

09-24-2009, 07:18 AM	#1
pinkgyrl Stock Join Date: Sep 2009 Location: Little Rock, Arkansas Posts: 6	Give a girl a brake and help her out? ;) Any help appreciated. I have a 1998 stock Supra; I purchased it in 1998, and I've been the only owner. It's never had any mechanical problems except for last year when the heater stopped getting hot (hehe...so many bad pun opportunities here...grin) The "check engine" light came on last week. When you push the gas down nothing happens until you push it to the floor, and then it will accelerate. Every once in awhile, it will "jump" back into normal driving mode and be fine for an acceleration. It's had a diagnostic, which my apologies - I am not a mechanic, the first showed a failed thermostat (it's been replaced) and the second code indicated that the throttle sensor was bad - this has also been replaced now after waiting 3 days for the part. After these two parts were replaced, the car ran fine on the test drive. After it ran and then sat for awhile, the same problem started all over again. Any ideas at all? My roommate works a repair shop, but he hardly has any free time during the day to spend on it - so, I'm stranded currently. Thanks for reading! Wendy

09-25-2009, 07:36 PM	#2
Krem 3" Exhaust Join Date: Sep 2009 Location: Las Vegas Posts: 167	Do you have a manual or auto? Doubt the tranny is the problem, but if your acceleration is poor because the gears aren't shifting on an automatic, it could be a possibility. I was thinking Throttle Position Sensor the whole time reading your description, but you mentioned you replaced it... when you lower the gas, does the engine rev up higher and higher but your speed remains constant until it's Full Open Throttle? or do your RPMs remain low until you get FOT and then you also get acceleration? If your rpms climb but the car doesn't accelerate, I'd be willing to blame the transmission.. if you don't build any rpms until you're FOT, then it could be the throttle position sensor still (could have been installed incorrectly?) or probably something in the fuel system... either the injectors or filter are clogged up... when you push the pedal down enough, you're pushing enough gas to get past the clog... but not until then.. Dunno, kinda shootin darts in the dark... I'm a computer guy, not a mechanic... but knowing how the systems work (in generalized detail) has drawn me to these conclusions... if someone more mechanically enclined has other advice, I'd strongly suggest taking theirs over mine.