Question about 1990 Mercury Grand Marquis
1990 mercury g/m-5.0L-V8-EFI, mileage-86,000mi, Ignition & fuel systems appear OK. No service light,no codes. After restart at high speed idle ,engine will reduce rpm & continue to operate ,but at times will stall unless accelerator is depressed to maintain rpm. After warm-up engine is OK. Cold start is the issue. Please help. Thank you.
I had a similar problem. I found the filter cartridge below the pcv valve had carboned up, and after the crank case pressurized, oil was forced out the pcv supply line to the throttle body. The idle air control valve solenoid got oil in it and caused my problem, but only when it was cold. The pcv cartridge is accessed by removing the pcv valve and the rubber fitting that the pcv valve mounts in. It can then be fished out with a pick set, and it is a pain because you can't see it, but you can get you hand back there. I hope this helps you.
Posted on Feb 28, 2009
Well the first thing that comes to mind is the idle air control valve located on plenum/throttle body. that valve controls the air flow to engine when its at idle. could remove, clean shaft with carb cleaner and lubricate. and see if that makes any difference. valve may need replacing but this is a good test
Posted on Dec 07, 2008
a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
Tips for a great answer:
Apr 25, 2016 | Geo Cars & Trucks
Feb 18, 2014 | Toyota 105 Cars & Trucks
Feb 05, 2014 | Jeep Wrangler Cars & Trucks
Dec 12, 2013 | 1989 Toyota Camry
Oct 28, 2013 | 1996 Honda Prelude
Mar 27, 2009 | 1995 Toyota Camry
Oct 29, 2008 | 1999 Mercury Grand Marquis
746 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: