Diagnose my car

I have a 2002 Chevy Astro van. Sometimes, when I go to start it, the engine will rev up and up and up, as if I am leaning on the gas or the ignition when I’m not. After a few seconds, I’ll turn the car off for fear it will explode. I’ll let it rest for about 15 seconds, then try again. Roughly half the time, the van will start up normally on the second try. The other half of the time, it’ll repeat the high rev thing and I’ll turn it off again. The third try almost always results in a smooth start-up.
It only occasionally does this after it has been running. Instead, it’s almost always a first start-up of the day thing. But, many days it starts as a normal vehicle should.

What is going on? I suspect the starter is sticking somehow, but I’m not familiar enough with cars to know if a starter can possibly do that.

The first episodes of this were about 6 months ago. We got the oil changed and that seemed to relieve the symptom for a while. Now, in the last couple days, it has started again, despite another oil change last week.

Second question: This same van had a busted rear window for the last year and a half. We had it covered over with plastic and duct tape. We were finally able to get the window replaced, but now we have a rim of duct tape residue on the paint. Anyone got a good goo-remover that won’t take off the finish?

It’s not the starter.

Do you press down, maybe floor, the accelerator pedal before starting? If so, the problem may be a sticky throttle (the flap in the air intake controlled by said pedal). This can usually be cured by a good cleaning of the throttle body. Note that the pedal should not be depressed before starting – that’s a technique from the days of carburetors, which is unnecessary on today’s fuel-injected engines.

If that’s not it, I would suspect a faulty idle air controller. It could be sticking in its full-open (help the engine start) position.

No, I don’t touch the accelerator, unless I’m doing it unwittingly. I do sometimes depress the brake when starting. It’s a paranoia habit left over from my days of owning a stick shift. Is this bad?

So, sticky idle air controller, eh? How tricky a thing is that to fix?

No, no problem.

Maybe.

Usually fairly simple. Access on some vans isn’t as good as on most cars, but still not a big job.