86 Grand Marquis Stalling

[demons19]

Hi, my 1986 Mercury Marquis has 126K miles and normally runs pretty darn good. In fact, when right, the ride is still very smooth.....But, periodically, the car has spells where it stalls alot in gear. I can be at a red light and just like that it stalls. I can be driving thru an intersection and moving slowly and it could stall. It never will do this will my foot is on the gas pedal moving quickly. But, take your foot off the gas and it could stall easily. It always starts right up again but the care now requires a skillful driver to use the brake and gas at the same time for driving off highways........someone mentioned that it needs a new gas filter. Does this sound correct? Is this something an idiot like me can easily replace?

Thanks
Rich

[fredjacksonsan]

I had the same problem, it is common for that year. Mine was the Idle Air Valve/Motor and there's a post in this forum about it.

There are also other posts concerning the same type problem, but I'd start with the IAV/M. Easy fix.

[glasser3]

my 87 has the same problem and im looking for any quick fixes to get it back on the road for another week till i get paid

[bdomarat]

Read my post on 92 GM stalls at idle. Sounds too good to be true but cleaning the throuttle body and plate worked for me- was recommended by a mechanic who could have sold me an idle air bypass valve.

[glasser3]

already tried that didnt help ... was told it was the module on the distributor by a mechanic friend of mine so now ive gotta try that i guess

[reekor]

If the car starts right up after stalling, I would look at the Idle Air Valve, they are problematic on the 5.0's. Your mechanic friend should be able to verify the functionality of both the Idle Air Valve and Ignition Module with a KOER test.

Originally Posted by glasser3

already tried that didnt help ... was told it was the module on the distributor by a mechanic friend of mine so now ive gotta try that i guess

[glasser3]

ive already had the idle air valve checked and cleaned and that was found to be working fine but the car does not start at all now so im assuming its the ignition module .. at least im hoping it is

[Marco Sr.]

I had a simular problem, although not quite the same since mine wouldn't start right back up but it would start after about 15-20 minutes it turned out that the pickup module in the distributor was failing on high heat conditions (Outside air temps of 85 and above, the hotter it was outside the more frequent it would stall out).

If yours is doing this on cooler days then it could verywell be a dirty EGR valve since it does directly affect the idle state as well as low speed states but not effect say above 1500 rpm's.

Marco

Originally Posted by glasser3

ive already had the idle air valve checked and cleaned and that was found to be working fine but the car does not start at all now so im assuming its the ignition module .. at least im hoping it is

[rhandwor]

Many problems are caused by a leaking intake manifold gasket. Spray along side the intake manifold if you have an air leak it will imediately smooth out. Also spray alongside the throddle body. Unplug the vacuum booster and put a bolt in the hose to check for leaks.If leaking buy a rebuilt unit. Spray around the rubber hoses. Wiggle the wiring to the distributor does this change the engine speed.