Engine Performance problem
1993 Eagle Talon 4 cyl Front Wheel Drive Automatic 140000 miles
MY DAUGHTER'S 1990 EAGLE TALON W/ A 1993 2.0 MOTOR AND AUTO TRANSMISSION IN IT WAS IDLING HIGH AND SHE ASKED ME TO LOOK AT IT. I FOUND THAT IT HAD AN ANTIFREEZE LEAK. I KNOW FROM EXPERIENCE THAT YOU CAN GET AN AIR BUBBLE TRAPPED IN THE COOLING SYSTEM CAUSING THE SENSOR TO HAVE IRRATIC IDLE. TURNED OUT TO BE A BAD WATER PUMP. I CHANGED THE WATER PUMP, AUTO TENSIONER, TIMMING BELTS, AND PULLEYS. INSTALLED AS SPEC'ED AND STARTED CAR. THE IDLE WENT UP TO 2,500 RPM THEN DROPS TO 1,900-2,000 RPM AND GOES NO LOWER. I RAN THE CAR OUT AND THE THE CAR RUNS FINE ALL EXCEPT THAT THE IDLE NEVER DROPS DOWN TO 800 RPM. I ALSO BELEIVE THAT I'VE GOT ALL AIR THAT WAS TRAPPED IN COOLING SYSTEM OUT - VIA ELEVATING THE RADIATOR CAP HOUSING. THE TEMP. SENSOR FOR FAN RUN IS FINE. THE SENSOR BELOW THE THERMOSTAT READS 2266 OHMS WHEN COLD AND 224 OHMS WHEN HOT. IF I REMOVE THE ELECT. CONNECTION TO IT WHILE RUNNING THE IDLE JUMPS TO 3,000 RPM. THE TEMP SENSOR ABOVE THE T-STAT IS DEAD SHORT WHEN COLD AND DEAD SHORT WHEN HOT. I THINK THAT THIS MAY BE THE CULPRIT BUT AM UNSURE. I ALSO READ IN THIS FORUM ABOUT AN AUTO IDLE SENSOR IN THE AIR FILTER THAT COULD BE BAD OR DIRTY. I WAS UNAWARE OF THIS OR ARE YOU SPEAKING OF THE THIN NEEDLE W A HOLE THROUGH IT THAT MONITORS THE AIR FLOW? IF NOT WHERE IS IT? CAN YOU HELP PLEASE?
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.