What causes my Merc to not idle after short trips and bog down going up steep hills?
Asked by Msfixit12 Jun 05, 2017 at 09:22 AM about the 1989 Mercury Grand Marquis LS Sedan RWD
Question type: Maintenance & Repair
It idles fine when first started. After driving and parking, it won't idle when I
restart. Once I park it over nite, It starts and idles fine again. Also, after a long
day of starts and stops, it bogs down on steep hills.
3 Answers
Trippmeister answered 7 years ago
Do a scan, or have one done. Could be you need to clean or replace the MAF sensor. Could be TPS sensor. Maybe valve body dirt, or clogged passages. There are guys on here who know more. Also check fuel pressure.
Update: It turned out to be the Idle Air control Valve. Just had to remove and give it a good cleaning to remove the carbon. Thankx for taking the time to try to help.