Engine Mechanical problem
1997 Geo Metro 4 cyl Front Wheel Drive Automatic 200000 miles
We have a 97 Geo Metro with a 4 cylinder.
Recently we began having problems with it staying running until eventually it would not even start at all. A friend suggested we replace the throttle positioning sensor, which made sense, so we did.
Now it starts, no problem, unfortunately, the throttle is stuck WIDE open and will not throttle down. We tried resetting the computer but that did not help. We can’t leave it running long enough to mess with it for fear it will blow up. And don’t really have a clue as to where to start.
Does anyone have any suggestions?
With fuel prices approaching $4 a gallon in Washington state, it would be so nice to have the Geo running again.
Thank you in advance.
Too fast an idle speed. If an engine without computerized idle speed control is idling too fast and refuses to come down to a normal idle speed despite your best efforts to back off the carburetor idle speed screw or air bypass adjustment screw (fuel injection), air is getting past the throttle somewhere. Common leak paths include the carburetor and throttle body gaskets, carburetor insulator spacers, intake manifold gaskets, and of course, any of the engine's vacuum fittings, hoses and accessories. It is even possible that leaky O-rings around the fuel injectors are allowing air to leak past the seals. Another overlooked item can be a worn throttle shaft and a defective idle speed speed control motor/valve stuck in the extended (high idle speed) position/throttle position sensor.