1994 Mercury Grand Marquis stops running at long stoplights

94mgm9494mgm94 Member Posts: 3
edited August 2014 in Mercury
I had replaced the MASS AIRFLOW SENSOR a couple of weeks ago because during cold starts I would have to wait a couple of minutes just to warm up the car before the car could move forward, it would basically jerk back and forth and stall before pressing on the gas. Now, that doesn't happpen, after it was replaced no more hesitation, but now I don't hear the engine, no more rough idling, the engine is quiet as if It is about to die on me. While in drive and when at a long stoplight, or railroad crossing, my engine would just shut off, its as if it never reaches idle. I was thinking it can be the AIR BYBASS VALVE but there many names for that. I really think it soething to do with my idling. Anyone please help....I have had my car for four years and I never had a problem until now?!?


  • ronslakie1ronslakie1 Member Posts: 57
    This sounds as though it might be a bad Idle Air Control Valve, which is not really difficult to change and I believe is in the $60-$80 price range. I had the same problem with my 01 MGM and the IAC was the problem.
  • 94mgm9494mgm94 Member Posts: 3
    Thanks....I will be working on that today...you are right on the price...but the IAC valve is all the way in the back of the engine behind the throttle body...it looks difficult to even get a tool around there any suggestions?
  • ksnappksnapp Member Posts: 1
    i posted on here a few days ago with a similar problem . i read what you did and thought i would give it a try but i just un plugged it . car runs better than it ever has . i almost junked it cause ive been trying to figure out this problem for months . thanks for your post
  • euphoniumeuphonium Great Northwest, West of the Cascades.Member Posts: 3,425
    Which did you "unplug"? The Mass Air Sensor or the Idle Bypass Valve?
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