Internet forums, and multiple calls into CarTalk that I've heard, seem to indicate that my particular model and year of Accord (2000 4cyl) is extra-suceptible to this problem. EVERYONE is having this problem with their 2000 Accords.

First thing in the morning, my throttle is sticky, and I have to push harder on the pedal to dislodge it. Making a quick VROOM when it breaks free.

I have repaired this multiple times by disconnecting the rubber shroud that goes from the air cleaner to the throttle, and wiping the black gunk off edges of the throttle plate and the inside of the throttle body with a paper towel. After I do this, it's usually fine for a number of months.

It keeps coming back, though, and I'm wondering if there is an easier way to deal with it. It's very hard to get my fingers in there to wipe it with the paper towel. This morning I tried and couldn't get much of the black stuff out of there, probably because I wasn't reaching deep enough. The throttle was still sticky afterwards.

I have the urge to spray a bunch of solvent into the throttle body. I seem to recall a product called "Gumout" that's made specifically for it. But I'm also afraid to spray chemicals in there because I'm worried that I'll contaminate the valves or dislodge large amounts of that black crud, and make my (up until now trouble-free) engine do something bad because it's now got gritty stuff suddenly going into the valves and cylinders.

Is it safe for me to spray something in there (and if so, what), or should I just keep with the manual wiping of the throttle body thing?

Is it safe for me to spray something in there

Maybe yes, maybe no.

Research very carefully. One of the things you have to find out is whether the product is "sensor safe". You can wreck your O2 sensors in short order by running the wrong chemical past them.

For example, in Alaska we attach heating pads to the oil pans of our engines, so at night we can plug the car in and keep the oil warm. These pads are attached with RTV silicone, and it is important to buy the product that is listed as being Sensor Safe. The non-safe fumes (smells like vinegar. Acetic acid?) from "regular" RTV silicone as it cures can get sucked into the air intake and damage the O2 sensors.

I wouldn't worry too much about "dislodge large amounts of that black crud," since there really isn't very much of it in that throttle body, it is apparently pretty soft (you can wipe it off with a rag) and you'd be surprised at just how much stuff your engine can ingest and spit out the exhaust without damage.

Be glad your sticking throttle butterfly is not the same one that the Ford Taurus has. In that case, the butterfly valve actually wears a groove in the throttle body housing. Only known remedy is to replace the entire throttle body assembly, at a cost of about $600 if memory serves me correctly.

tanstaafl.

you can use 'carb cleaner', but rather than spray it down the throttle I would just spray it on to a rag and use the same method you use now. it'll make cleaning easier, but wont really fix the problem.
the build up of crap is probably coming from the crankcase ventilation system. check or replace the 'pcv' valve(located in the valve cover), this may help some, or at least put off the problems associated with a bad valve. remember that the crap that's jamming the throttle flows through this valve and will likely clog or jam it's operation too.

another thing you may want to inspect is the throttle stop angle. if it's set too low it'll be easier for the crap to jam it.

fuel cleaner that's placed in the fuel tank will do you no good at all. don't bother.

worn piston / rings will cause excessive blow-by, it's residue is what's collecting on the throttle plate.


see here : http://got.net/~danj/cust/hondathrot.pdf 663KB

Thank you for that great information, Doug and Dan. That's very good to know. When it stops raining, I'll go to an auto parts store and see what they've got. I'll let you know how things go.

Wow- that's a very nice document!
The expansion/contraction concept hadn't occured to me.
I wonder if there is some way to coat the parts so that they'll not get stuck- some sort of teflon coating?
Nice to see such a thorough 'How To'.