1995 Mercury Sable Engine racing

JMUL

MEMBER
1995 MERCURY SABLE
6 CYL
FWD
AUTOMATIC
140,000 MILES

My mercury sable seems to race too high, from a dead stop upon releasing the brake it will travel about 15-17 miles per hour with touch the acelerator.
When stopping, the transmission cllunks, The tach reading is over 1000RPM's and sometimes during slowdown there is a pause in the transmission before down shifting. At highway speeds it seems it takes a long time to decrease speed when easing off the accelerator.

It happens very frequently, but not always.

2 Replies

BMRFIXIT

MECHANIC
19,053 POSTS

I would say its the idle air control relay
check for vacuum leaks check around the PCV valve and it hose
check / replace idle air control valve

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Thursday, August 28th, 2008 AT 4:53 PM

RASMATAZ

MECHANIC
75,992 POSTS

Also you might want to check other stuffs see below

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.