It's supposed to do that. It is the "dash pot" emulating putting your foot on the accelerator to start the car. The computer does all that for you. Keeps stupid people from flooding the engine out. That is your "dashpot" at work. It's supposed to "rev up" and then calm back down. It imitates putting your foot on the accelerator
no, check your fluid levels.
Your 1987 Astro might go full throttle when the engine is started because the throttle is sticking. This could also be a problem with the starter or the ignition hanging during the start.
If you have knocking from the engine and smoke from the exhaust then you have far more problems than the car just not starting. Sick professional help immediately.
Yes, particularly the throttle position sensor. But it could also be literally thousands of other things.
Could just be throttle plate sticking--without engine running try to free with a screwdriver Could just be throttle plate sticking--without engine running try to free with a screwdriver
Could be that the throttle plate (in throttle body) is stuck open. Try to "free up" by sticking a screw driver into throttle body
Could be a starter solenoid going bad, it could be ECM problems, it could be a number of things.
could be your throttle position sensor or check and make sure butterfly flap is closing properly.
P2112- Throttle actuator control system stuck closed. The throttle on your vehicle is not controlled by a cable but by a actuator motor in conjunction with a sensor inside the accelerator pedal. This fault indicates there is a problem with the throttle side of the system. The throttle is either binding, slow to respond, completely stuck or has failed. Other possible causes include problems in the wiring (open/short circuit) faulty connection(s), or battery voltage problems could also cause this. I would try checking the connections to the throttle actuator, and if you are up to it carefully clean the throttle to see if you can save it. Good luck!
About a million and one different things can make that happen.
could be distributor cap or rotor
pcv rerouts exhaust air to the air filter,it functions by opening and closing relative to rpm, as rereouted exhaust could lean the mixture. so the engine could develop cold starting problems and backfire while decelarating