Throttle sticking

Having a problem with my 2002 Sienna. The accelerator is sticking occasionally - not every time but fairly often. When I am off the gas pedal at a stop, and then just start to push down on it, nothing happens (the pedal doesn't move at all). As I push harder, it suddenly lets go, and the car jumps forward from having too much pressure on the pedal.



It is not a lot of pressure to get it moving, just enough so it is not a smooth start.



I lubed the pedal spring under the dash, and the throttle assembly under the hood with no results.



Is the computer doing this? Or is it a physical sticking somewhere on the throttle cable?

Reply 1 : Throttle sticking

Most likely carbon and crud build-up on throttle blades is the cause, get a can of carb cleaner and a small brush {an old toothbrush} remove intake hoses and spray and scrub, may need to hold gas pedal 1/2 way down to re-start first time.

Reply 2 : Throttle sticking

dealership wanted about $120 to clean throttle body on our 2002 van.



I know you can clean throttle with a can of throttle body cleaner.



But be sure get the right stuff and check with someone who is up on this procedure. If you ruin a sensor inside throttle body you could cause yourself more problems.

Reply 3 : Throttle sticking

Did what was recommended above, cleaned out the intake with throttle body cleaner, and it works great now.

Reply 4 : Throttle sticking

Have same problem and like a good newbie I performed a search to determine if this topic has been addressed yet. I know the Sienna was not part of the recall and I also see that some youngsters are spreading false rumors about throttles sticking, so I was reluctant to post.

But I see I am not the only one with this problem and I even have the solution.

THANK YOU!!

Reply 5 : Throttle sticking

i had a 2002 van and ran it 123K miles and never had a problem like that.



but what i did was pour a can of seafoam fuel system cleaner in tank twice a year, this stuff keeps the fuel system clean.



worked for me.



using this system you do not take the chance of ruin a few good sensors.

big bucks.

Reply 6 : Throttle sticking

A fuel system cleaner added to the fuel tanks is a good idea, however it will not do anything to clean the throttle body as fuel does not get there.

This is a picture of the throttle bodies on my 2003 Sienna.

The flex hose from the air filter box has been removed for access.

The IAC is in the right hand one......the one closest to the firewall, the hole in the bottom of the throttle body, near the throttle plate goes into the IAC.

This is what they look like when they are cleaned up.

Don't forget the back side of the throttle plates.

Reply 7 : Throttle sticking

Ima have to take a look at mine when I'm changing my valve cover gaskets next week. I might find a MPG in there somewhere.



I might do this project on Wednesday.



So far I'm looking at:

Changing the trans fluid,

Changing the valve cover gaskets,

Changing the plugs and wires (wires for the first time @ 220,000 miles),

Changing the PCV (this seems to be all that anyone on this forum talks about and mine is original),

Now I'm considering getting the can of cleaner to do the throttle body.



I also have to look into ball joints because I was cruising the other day at 85 MPH and I noticed a slight vibe. I'll get an alignment and then go from there. Toyota ball joints are kinda pricey.

Reply 8 : Throttle sticking

The slight vibe could also be from a tire.



Spark plug wires.......the Sienna does not have traditional spark plug wires.

We have a coil that mounts directly onto each spark plug.

You can see this in THIS picture......I have 1 pulled out of the spark plug tube in the front valve cover.









The correct transmission fluid will be a ATF that meets the Dexron III specification.

I am using Redline D4 ATF.

If you click on the picture above, it will take you into my folder of pictures for my 2003 Sienna.

I did remove the transmission pan, replace the filter, wipe down the pan and magnets, and did a cooler line fluid exchange.

Many do a couple of pan drains and refills.

There is another drain plug on the differential, which shares the same fluid with the transmission.

Draining the differential gets more of the old fluid out.......and it will be refilled when you fill the transmission through the dipstick tube.

The in-pan filter is nothing special, just a nylon screen.

I installed a Magnefine filter in the fluid cooler hose going back INTO the transmission from the coolers.



If you want to change the power steering fluid, it uses the SAME fluid as the transmission.

I have pictures that show how I did that........just unclip the power steering fluid resevoir from the inner fender and dump it into a container.....and refill with ATF.

No need to undo any hoses, etc.



I also have pictures that show the rear valve cover access......a bit of work.

Be very carefull installing the rear valve cover to avoid rolling the gasket out of place as you manuver the valve cover into place......a challenge with the big wire harness in the way.

Reply 9 : Throttle sticking

I almost did it today but I didn't I guess it will happen on Saturday. I had to take my other car to a body shop to see how much it was going to be to get it fixed. It's not as homely as our Sienna. Someone we know ran into it with their Expedition and it got a $600 scratch.



I've done the plugs before so I know what it takes to get to them. I don't do your extreme ATF changes. I just drop the pan and change the filter every 10,000 miles I use the cheapest ATF they have on the shelf. My power steering fluid is fresh from where I replaced the rack in the middle of December. I flushed the pump at the same time. I don't imagine the VCGs giving me much trouble. I might even take the time to soak them in my parts cleaner if the solvent didn't evaporate.



Have you ever tried LocTite's gasket glue stick thing. I've never used it on silicon gaskets but I've used it extensively for transmission pan gaskets. It works a lot better than axle grease.



I doubt the vibe problem is from the tires but it could be.