Mechanics

HIGH IDLE SPEEDS

2001 Chrysler PT Cruiser

Engine Mechanical problem
2001 Chrysler PT Cruiser 4 cyl Two Wheel Drive Manual 67000 miles

my pt crusier has recently upon start up been idleing at approx 1500rpm if I leave it for a couple of mins it returns to normal 800rpm, but if I drive away I keep getting high revs even whilst changing gears and braking to a stop with the clutch in any help please?
Avatar
Jakesy
September 1, 2008.



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. Also the throttle plate could be binding in its bore and kinked accelerator cable, coolant temperature sensor might not be operating properly misleading the computer that the engine is still cold and computer throwing fuel at it raising the idle speed.

Rasmataz
Sep 1, 2008.