Fast idle astro van

If it is still running away then you might have a vacuum leak or a stuck throttle.... turn off the engine get someone to step on the gas and watch the action of the throttle cable and look to see if anything is sticking...under no circumstance do you fire that engine while your body is under the hood.....if that fan belt snaps or a piece of clothing gets caught in the moving parts it will end with a trip to the hospital.

Fuse panel is usually located under the dash by the driver's feet or under the hood.

Check you steering and duspension system. Check ball joints and steering linkages. With the vehicle in the floor have someone move the steering wheel side to side. Not whole turns just side to side movement while you look at the steering linkage to identify any loose parts. Then raise the vehicle and check your ball joints by grabbing top and bottom of the tires and shaking them.

Check coolant level, and possibly replace thermostat. When a thermostat gets stuck in the closed position, coolant does not circulate thru motor. Gauge stays midrange when driving, because motor is being cooled by air and or the fan. If car seems to operate completely normal, then the gauge is faulty.

it sounds like a clogged catalytic converter. With the engine idling, put your hand at the tailpipe and check the pressure of the exhaust. If it is real low press. it is a clogged converter

Yes it could but also check under the hood because it is a very common problem for a vaccumm line to come unhooked causing this problem. Hope this helps, Allen, swiftautorepairs.com

Well.

The throttle linkage is sticking and no letting the accelerator pedal to release. The throttle body needs to be cleaned, The linkages need to be cleaned. IF the system still is sticking , Then there is a sensor for example the throttle position sensor or the Idle air control sensor is sticking . I would then take the vehicle in to be serviced by your local mechanic . The throttle position sensor or the Idle air control motor is not that expensive.
I would guess under 100.00 dollars in parts. and labor time under 1.0 hours to install.

Good Luck , and Slow down dudes.

it seems that the engine blew. the rings, rod bearings, main bearing etc. Sorry but it sounds like that. Especially the smoking at the exhaust. take it back to the one who sold it to you.If possible.

Idle step up or choke Check that the throttle plate is fully back on the idle screw.Make sure the return spring hasnt fallen off.

You are right to be concerned about this behavior since it can definitely increase your stopping distance.
Either your cable has eaten its way into the inner tubing and is hanging up, or the mechanics at the throttlebody needs some lubrication.
With no engine running, have someone inside to press on the accelerator while you watch for movement of the linkage under the hood. Once you have located it, operate it by hand to see how it feels. If the linkage does not return to the stops provided, then use a heavy-duty penetrating oil to soak the moving parts. If it still hangs, then the cable needs replacement.
With the engine running, tranny in Park and the parking brake on, after you have lubed the visible linkage, have some one inside press on the gas and watch the linkage to see if it now returns to the mechanical stop. Carefully move it by hand to see if it is truly at the limits of its travel where it should be at an idle.