SeanMG

Ok, so it started back at the start of fall into winter. When I started my car the RPMs will shoot to 2 or even up to 2.5 and stay there and will slowly... very slowly drop down to normal ~.75RPM. For the first 10 minutes of driving, the car will be extremely rough due to the RPM being so high and when I put the vehicle in gear, I have no need to even press the gas pedal because the car will drive itself and won't stall out. I've been told by people that it sounds like a Throttle Position Sensor, but when I tried to buy one from shops, they don't sell the TPS seperate from the whole throttle body...

With this issue my gas millage is horrible, and sometimes I can even smell gas while driving. I'm wondering if a sensor is bad but there is no CEL and plugging the car up to a computer reports no issues...

Anybody have suggestions? My car is Stock, Manual Transmission.

draxcaliber

you should also post up your year and your mileage. if MPG is horrible, could need new spark plugs, new primary o2 sensor. clear the MAF sensor, replace air filter etc.

SeanMG

2006 , 80,000 miles, I replaced spark plugs about 3000 miles ago, Air filter 5000 miles ago.

I'm about to go clean my MAF and see how that turns out. Found out online someone having symptoms exactly like mine cleaned his MAF and it's all good now.

mrexotica

Whatever you do, don't take it to your local dealership. They won't be able to tell you exactly what's wrong before you ruin your car.

SeanMG

Yeah I know that already, I took it to a couple shops and they said there was no problem... Grr... I cleaned off my MAF and it seemed to run better. The sensor was gunked up and black. But I have yet to let it sit overnight and test it's behavior in the morning. If that is still bad I'll clean up the throttle body, maybe that is gunked up too. If that doesn't help... I guess I'll need a TPS?

syberspyder

iTrader: (2)

You should also remove the NEG battery cable to reset the ecu so it can re-learn with your clean MAF sensor.(unless that's what you mean by "let it sit overnight")

mrexotica

Shops aren't dealerships with Toyota computers...

headlessmunky

iTrader: (2)

The rpm's will be slightly higher until the car warms up. Now on the shaking I have that issue. Now once the car warms up I don't have the shaking. When my car is cold, I will start it the rpm's will shoot to 2k-2.5k and hang for about 30-45 seconds and slowly drop. Then I would take off and go somewhere. Now I let it idle until it is warm because I am boosted.

SlverPnda

Sean I have an 06 with 84k miles and I'm not experiencing problems and mine is also a stick. probably you would have to replace the spark plugs and clean the maf sensor and what not.

SeanMG

Well, I cleaned the MAF, the Throttle Body, disconnected battery to allow to reset ECU. I installed new spark plugs a month ago -- when I did it seemed to fix my problem, however car would randomly idle as low as .5 and sometimes lower, however after 3 days it went back to the idling issue...

The car will only idle at .75 when the engine temperature is at half-way (the normal driving for 10+ minutes temperature) is there any sensor related to temperature that can be affecting me?

I wonder if it has something to do with the vacuum...

mrexotica

If it's the vacuum, it would usually idle high all the time, and would almost never idle low.
However, if you smell gas, besides being dangerous, it could be airflow-related.

Seriously, I would take it to a Toyota dealer, pay the diagnostic fee, and at least let them tell you what's wrong. No, I don't work for Toyota.

SlothytC

I have an 05 manual, and my car will do this in the mornings as well. The only difference is that mine will actually rev up and down on its own. It will go from 1500 to about 2200 RPM without me touching the gas pedal. It goes up and down for a minute or two then goes away. I've never really put much though into being a problem, but reading this thread makes me wonder.