Stored for the winter, now runs like crap! Help!
03-25-2011, 05:32 AM
#1
Thread Starter
Join Date: Sep 2010
Location: Indiana
Posts: 15
Stored for the winter, now runs like crap! Help!
I picked up my 99 mustang cobra convertible last fall. 
Only has 44,000 miles on her. I live in snowy/salty Indiana, so last fall I got it detailed, filled her up with 93 octane, and drove straight home, parked in the garage under its car cover. Twice this winter I pulled it into driveway and let it run 10-15 minutes.
Got it out last week and noticed sometimes under 2,000rpms it would miss and have like half power...... didn't want to rev. I thought maybe its cause the gas was 4 months old. So I just drove it till got just below half tank and filled it up with 93 and added a can of stp gas treatment. Its gotten worse. Now its all the time.
Just feels like its missing all the time and it hates being below 1,500rpm.
Any ideas? I am not new to cars or stangs, but AM new to the 99+ stangs. (was all fox body b4)
The obvious in my head is spark plugs, but hate throwing parts at a car until I can narrow down. Or hoping you guys now of something common on these that is common after storage that need cleaned like a tb or mass air or something.
Thanks for any and all input!
Only has 44,000 miles on her. I live in snowy/salty Indiana, so last fall I got it detailed, filled her up with 93 octane, and drove straight home, parked in the garage under its car cover. Twice this winter I pulled it into driveway and let it run 10-15 minutes.Got it out last week and noticed sometimes under 2,000rpms it would miss and have like half power...... didn't want to rev. I thought maybe its cause the gas was 4 months old. So I just drove it till got just below half tank and filled it up with 93 and added a can of stp gas treatment. Its gotten worse. Now its all the time.
Just feels like its missing all the time and it hates being below 1,500rpm.
Any ideas? I am not new to cars or stangs, but AM new to the 99+ stangs. (was all fox body b4)
The obvious in my head is spark plugs, but hate throwing parts at a car until I can narrow down. Or hoping you guys now of something common on these that is common after storage that need cleaned like a tb or mass air or something.
Thanks for any and all input!
03-25-2011, 05:34 AM
#2
Could of been the gas from not adding stabalizer, when you're dealing with stale gas its better to keep adding and topping off then running the bad gas out, rare but the plugs could of got fowled from the bad gas.
03-25-2011, 05:54 AM
#3
Thread Starter
Join Date: Sep 2010
Location: Indiana
Posts: 15
So your saying dont run tank low, but fill up before half empty?
03-25-2011, 08:01 AM
#5
If that was the case i'd be dropping the tank to get the bad gas out and put fresh in. Could also be a COP or dirty/dusty maf. Try cleaning the maf as well. Seafoam it too through the vacuum hose, clean out all the deposits in the motor and such.
03-25-2011, 07:43 PM
#7
Thread Starter
Join Date: Sep 2010
Location: Indiana
Posts: 15
03-26-2011, 01:25 PM
#9
5th Gear Member
Join Date: Jan 2008
Location: Canada
Posts: 3,306
The COP is the Coil on Plug. Basically your ignition coil and plug wire in one unit.
The fuel filter is in front of the gas tank, above the rear end. Is your 99 a SRA or IRS car? Ive heard changing the fuel filter on a IRS car is a PITA.
The fuel filter is in front of the gas tank, above the rear end. Is your 99 a SRA or IRS car? Ive heard changing the fuel filter on a IRS car is a PITA.
03-26-2011, 03:14 PM
#10
Thread Starter
Join Date: Sep 2010
Location: Indiana
Posts: 15
It's an IRS car. So ur not saying clean the cop, your saying they could be bad?