Expert: Sean Halliday - 2/13/2008

Question
When I start my 2001 Ford Taurus after it's sat overnight, it idles rough, like it wants to stall.  Once it's warm, it runs smooth.  My engine light keeps coming on and says "cylinder misfire".  I've had a tune-up, throttle body has been cleaned, EGR valve replaced, and I still have this problem.  Please help.  I don't want to spend a ton of money trying to find the problem.

Answer
What did the "tune up" include?It is a misfire when the car is cold and could be a leak at the intake or a bad wire,plug,im betting it is a leaky intake manifold gasket.You need to look at the car when cold.Check the compression on all cylinders so you eliminate that.Then,the code will tell you which cylinder is not firing or random, then look at all the plugs.It is usually hard to find a leak at the intake without expensive shop equipment so its fairly cheap to buy a new gasket and fit it yourself.You need to remove the intake anyway to look at the rear plugs.Change the gasket and see if it helps.