throttle sticking 99 SS

[The Beast]

I just took out my 99 SS since it has been in storage and drove it around and noticed when I remove my foot off the throttle at around 40 mph the car does not slow down so I put the car in nuetral its a automatic and rpm is around 1900 rpm. When I stop at at a light or stop sign the car is at idle around 700 rpm which is normal. What sensor or part could it be? has anyone experienced this before?? I'm thinking IAC sensor but I don't want to buy it and it not fix problem. The car is bonestock except for a lid and k&n. any input would will be helpful thanks in advance.

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[Eagle]

yep, clean the IAC first. Past that, has the car been tuned? This could easily be a tune issue as well.

 

[Eagle]

PS - Does it have a toyota sign/sticker on it?

 

[BillyBru]

PS - Does it have a toyota sign/sticker on it?

haha i was just thinking that.

 

[02BlueGT]

Check the TB for gunk, a slight build up(normally at the bottom) will cause the blade to stick a little open, then air gets in over the top of the blade, this will also cause it to take more pedal movement to make the same RPM's that it used to(limited air flow at teh bottom the the blade during part throttle)....

Or your IAC could be gunked up

 

[02BlueGT]

Damn Eagle and beating me to the point

 

[greasy]

I would clean the IAC with some carb cleaner and make sure your TB is not all gummed up with carbon as well.

 

[Runtz52]

same issue with my lumina, the alternator was goin out and it was revin it self up to try and keep it charging, idk what rpms it was at but when i was at a light i had to pedal to the floor and it was still rolling, that could be ur issue as well

 

[Eagle]

 

[02BlueGT]

 

[Eagle]

 

[The Beast]

yep, clean the IAC first. Past that, has the car been tuned? This could easily be a tune issue as well.

The car is bone stock all i installed was a k&n and lid that is all. I will clean iac today. It's just my grocery getter in the summer.

PS - Does it have a toyota sign/sticker on it?

LOL Only difference is throttle does not accelerate at full throttle stays around 1700 rpm- 1900 rpm snd comes back down when i stop.

haha i was just thinking that.

No toyota. I see we have comedians on the garage. lol

Check the TB for gunk, a slight build up(normally at the bottom) will cause the blade to stick a little open, then air gets in over the top of the blade, this will also cause it to take more pedal movement to make the same RPM's that it used to(limited air flow at teh bottom the the blade during part throttle)....

Or your IAC could be gunked up

Around October my buddy replaced the idler pulley and 2 belts and noticed the throttle body was dirty and he cleaned it. I will check again and re clean it with brake cleaner and iac.

 

[The Beast]

same issue with my lumina, the alternator was goin out and it was revin it self up to try and keep it charging, idk what rpms it was at but when i was at a light i had to pedal to the floor and it was still rolling, that could be ur issue as well

At a light and foot on brake the rpm is at 700 rpm no surging.

 

[Bad00SS]

if the car has a FAST 78 or 90mm throttle body this is a known problem. I assume yours is stock tho. my 91 z28 had this happen and the throttle cable was getting cought up where it passes thru the fire wall. put a new throttle cable on it from the dealer for $20 and fixed it. possible the IAC is acting up. clean the throttle body real good and start from there.

 

[The Beast]

Okay guys I just wanted to say thanks to everyone I took everyone's advice and traded it in for a Toyota.

















































































Just kidding I took everyone's advice and cleaned the IAC sensor and replaced the throttle position sensor and problem is fixed. thanks for the helpful advice.