Throttle sticks open!!!
 

I was only able to get it to do this after jumping off the line to instigate it, another account says third gear, the third occurrence was an attempt to move the car one length forward, which ended with a panicking, but successful brake attempt which spared the garage door. It seems the throttle will stick open, or throw itself open. Has anyone dealt with, or heard of this problem and possible solutions? I would love to get this bad bear back on the road, but its too damn unsafe to drive, and plus- if I can save a few hundred in labor at the local shop I am all for it. Any help is greatly appreciated!

Does it only do it under boost conditions?

I actually don't know exactly. Would there be a specific diagnosis for each condition? I have been told to clean the throttle body, but I don't exactly know if that will take care of the problem as a whole or what. I have heard a TB cleaning will help cars that stall, but I am having the opposite problem. That fix would make sense to me- but I feel there could be something else. I am going to do that fix no matter what this weekend, but if there was something else I could do as a bit more insurance, it would help.

Also clean the idle motor.

I asked about under boost because I had it happen to me on the highway. I stepped on it to pass someone and when it went into boost the throttle body hose swelled and held the throttle wide open. Then a few miles down the road the throttle body hose blew a hole in it.

So ling story short my hose was bad.

could it be that the spring is bad/broke that holds the TB shut? long shot i know, but possible

my throttle gets stuck every once in awhile if i floor the pedal in first gear...
still not sure...no time to check either.

Visually inspect the throttle cable & linkage. Clean & lube if you must.


JPN

+1, I forgot to mention that the cable could be getting stuck on the spoil and causing the cable to rid in the rig wrong. This would keep the throttle from closing all the way.

Another tip as well. Also see if the mount at the firewall is broke. If it is they can hang the throttle open.

I must say thanks to all that helped me out with this- I sprayed and scraped the throttle body down to release carbon deposits, and also lubricated the throttle linkages because they appeared quite rusty and were certainly sticking, I am assuming these will have to b replaced at some point soon, but for now, the engine doesn't race and I haven't wound up in somebody's back seat or through the garage door.
Once again, thanks for the help!

Excellent!!!


JPN

I have this same problem - lately throttle has been sticking occasionally at or near WOT. I noticed this happens as it started getting cold, and only soon after driving. My car (96 850R 127K) is hardly driven so I got in the habit of pumping the gas pedal all the way several times to loosen it up before starting and driving.

2 weeks ago I did this and the pedal never came back up. Tried to work it loose under the hood and the cable came off the pulley so I had to open it up to fix. Looks like sticking is due to the linkage - rusty and sticks when pulley is fully rotated.

What do you recommend to lube this up? Should I also clean and lube the TB and cable? Does anyone have a procedure for this? (I don't want to mess any of this up!)

Thanks

I would clean the throttle body good. Then remove the linkage and clean the balls that it connects to. Then use some silicon based grease then reinstall.

Just summing up what I did to fix the problem- I took the intake hose off the throttle body and used a spray (throttle body or carburetor) cleaner with a toothbrush and went to work for a while. After that was done I checked the throttle cable again and it sprang right back to its original position (essentially solving the throttle sticking open problem). While I was under the hood I figured I would pop the linkage balls and do a bit with them. I popped them, and used a brush to get the rough rust out and then used white lithium grease I believe it was as a lubricant for the linkage balls. It certainly isn't a new volvo, but it is surely night and day now that this procedure has been done.

I have had the experience with my 06, xc90. It would also restart to maximum throttle three times after disengaging the battery.

Turned it off and coasted but the engine sounded as if it would fly apart. I replaced the throttle body for $1,000.$ + and it still does it. I don't dare to floor it now.

How would one go about lubing the throttle body? This is my first car and when I step on the gas pedal, it sticks and the engine goes wide open. I popped the hood and found the throttle body pulley controller to not be returning to its seat. The car sat for a year and I'm sure the throttle body pulley controller part needs to be lubed somehow. many thanks for any information.