Mazda6 sticking throttle

Hey guys, my mother has a 2003 Mazda6 GSX 2.3 travelled 158kms and the throttle will often stick shut and require extra force to open the throttle again resulting in a sudden surge of power, which makes things like parallel parking difficult. A short time ago when it first started doing it I took off the inlet hose and cleaned out the muck which was surrounding the throttle plate, but I didn't notice a great deal of it accumulated. I noticed that the throttle body was plastic and the throttle plate was metal with relatively sharp edges, and it almost looked like the throttle plate was eating into the plastic internals of the throttlebody every time it shut, and therefore sticks into place. After cleaning it out, it seemed to behave itself but only for a few weeks and the stickyness came back. She's gone to Australia for a few weeks and has left me the car in the meantime (gotta do an oil change on it etc), so I figured I would sort out the throttle issue for her at the same time. Would applying a light smearing of grease around the inside of the throttlebody where the throtte plate makes contact be a sensible or a silly thing to do!

Aside from from the obvious plastic binding on the metal butterfly some throttle body's have synthetic rubber grommets that the pin that goes through the butterfly pivot on. (you wont see them of course) Getting some oil on a cotton bud and oiling around the holes where they butterfly pin goes and moving the butterfly as you do it, can help lube them back up as they dry out. Oil does not seem to perish them.

This is a classic problem with those dodgy Volvo throttle body's BTW and they are often thrown away because people think its more serious given the reputation of that unit.

Also. while you are on the case give the battery a load test. Weak battery's are known to cause the kind of sticking you describe even though the car may be starting and otherwise running O.K.
Checking the voltage to the throttle body actuator and ecu is also a good idea. This assumes of course that its a "fly by wire system"

Other than that I have not messed with a plastic throttle body before so hopefully someone can advise better on what to do with the actual butterfly.

Of course it may just be binding as you say but thought you might want to tuck those ideas away in case it mysteriously dosn't improve.

hey Jazz thanks for that advice. It's the pre-facelift model so is still cable actuated, the facelifts have fly by wire.

ah okremove the cablefully out of the car. my guess is its got a kink damage somewhere and gets stuck.

nah it's definitely the throttlebody, if you unhook the cable the throttle still sticks when you move it manually at the throttle end.

Ahhh O.K sorry its beyond me then, the only ones I have had a lot to do with are the Volvo ones for obvious reasons and they are fly by wire. Just thought I would pass on what I know as a long shot since you were not getting much in the way of a response.

My only other thoughts are, I take it you got really thorough with the cleaning! I have seen some where they have been cleaned but people have missedup around the pivot points of the butterfly and thats still caused trouble. I tend to get busy up around there with an old toothbrush and throttle body cleaner rather than just the cleaner and a rag.

My only other absolute wild guess is it seems odd that the butterfly is digging into the plastic, I wonder if there is a stopper for the butterfly that has worn, broken or come adrift. Perhaps even the pivot bearings/gromets have worn or the butterfly is not sitting square in the pivot shaft as that just does not sound right to me.

The stopper of course would likely be under a cover on the outside of the throttle body somewhere near where the cable goes at a guess.

Just one other thing, it might be worth having a bit of a google, I seem to remember coming across a few Mazda's with issues when researching the Volvo problems.

Well thats all I've got! Best of luck with it and hopefully someone will come along who has some more relevant ideas.

I have the same sticking throttle problem on my 2003 Mazda6. It seems to appear when the weather is cold.
Recently, I was on a long run and was using the cruise control. Sometimes after coming out of c/c, the throttle stuck in position partly open, would not open further smoothly and needed some force to get it to work.
Would this help with a diagnosis?