Hi folks,

Those with older Prius need to read-up, especially if you're out of warranty. After 3-4 years, 'stuff' can accumulate around the throttle plate causing it to stick and the engine fail to start. The car reports an error but often, you can start the car by trying again. After three restarts, the error code clears. Unfortunately, the standard Toyota answer involves replacing ECU, fuel pump and fuel tank. This is OK if under warranty but if not, $1,800+.

A sticky throttle plate can occur any time and I drove for about five months with one. There have been a few reports in the summer but my experience has been cold, wet weather seemed to bring it on. Fortunately, the local Toyota service technician turned me on to this trick of cleaning the throttle plate when I tried to get them to replace the ECU under warranty.


HOW TO CLEAN THROTTLE PLATE
To clean the throttle plate, Toyota sells a kit that includes throttle, fuel injector and vacuum hose cleaners that are safe for the catalytic converter, engine and fuel system. I picked up the cleaning brushes at a local auto-parts store:


The Toyota part number is 00054-00100 should cost $15-20:


If the throttle plate is sticking, you can test it by twisting the powerful return spring located just behind the oil dip-stick and under the air cleaner housing. It needs to be tested when the engine is a cool as possible because the heated manifold can loosen up the sticky stuff. If you can not move it cold, then throttle plate is sticking and cleaning it will cure the problem:


It is a strong spring but here I'm holding it with my finger. It rotates with the top going to the rear of the car and the bottom, where the stop tab I'm holding is located, rotating towards the front of the car:


Three clips hold the air cleaner cover. Replacing the air filter once a year is a cheap way to keep performance up and minimize dust and dirt:


Without the filter, it is easy to see the brass throttle plate. The air flow sensors are at the top and it is a good idea to avoid spraying it with cleaner. It is the throttle plate area that needs attention:


Just put the tube on the cleaner can and spray away:


If the throttle plate area is not sticking, it is easy to open with the hand. The first time, it was so sticky that I could not open it. So I sprayed the area and had a small pool of cleaner. I then started the engine and the powerful throttle motor opened it up. Thereafter, I turned off the engine and properly cleaned the area.


Once the throttle plate moves freely, use a combination of the long handled, narrow brush and spraying to clean the area:


My practice is to use at least half the can in the initial cleaning, drive around and use the rest. However, it is just as good to carry a little in the can until the next year. Your choice.

Be sure to pour the injector cleaner in the tank. As for the vacuum hose cleaner, I understand a special tool is needed but I don't have one nor any ideas of where to get one.

Questions?

Bob Wilson