1986 Mecrury Grand Marquis hesitation and sometimes stalling? - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

jmy2469 · 07-24-2010, 16:29

I have a 1986 Mercury Grand Marquis,with about 120,000 miles on it. Use this for my daily driver. Car runs good. Have this hesitation problem that I am trying to narrow down. When slowing down, to make a turn,the car sometimes stalls. If I keep my foot on the gas, I never have a problem with the car stalling. Always when slowing down and turning it happens. Any ideas what I can check to get rid of this hesitation and sometimes stalling?

**Bert** · 07-24-2010, 16:34

Try this to see if you can pull any codes. Ford Fuel Injection � How To Run a Self-Test. How is the idle normally? Fuel filter been changed?

jmy2469 · 07-24-2010, 16:45

I knew I would get a quick reply here. I have no idea when the last time the fuel filter was changed. Was thinking about picking one up and just changing it. When I first start the car in the morning, I'll let it run,it usually stalls. Start it again,then it will be fine.

**Bert** · 07-24-2010, 18:28

It's been awhile since I worked on those so I'll have to try to refresh my memory. Somebody else may pop in here with some help too.

**87_Crown_Vic** · 07-26-2010, 00:10

i would do a fuel filter and also take the idle air control valve off the throttle body and clean it out with carb cleaner... maybe a good tune-up is in order too...

**Bert** · 07-26-2010, 07:40

87_Crown_Vic always has good ideas on these older Crown Vics. He's done some nice work on his and others. Check some of his past posts.

jmy2469 · 07-26-2010, 08:06

Thanks for all of the help guys! Now I know where to start. I'll keep you posted

jmy2469 · 08-09-2010, 13:41

Just changed the iac over the weekend. Car stalling out more than before. When coming to a stop,car dies. Car runs great otherwise. Any ideas?

**87_Crown_Vic** · 08-11-2010, 23:58

makes me think the sensor unit took a crap on you that is located on passenger side close to the windshield... it has a plug of wires running to it and 1 vacuum line... the 5.0L in these cars didnt have maf sensors but instead used a different setup that i cant remember right now.... i know with that being unplugged it runs like crap if at all... you might wanna replace that vacuum line also since it is usually all cracked and might have a leak in it since it is rubber...

jmy2469 · 08-12-2010, 05:56

You are not talking about the idle air control, you are talking about somethings else right? Passenger side, and 1 vacuum line? I'll check it out,thanks.