Uneven Mustang Idle
courtesy of Bob, The Auto Answer Man
My 1990 Ford Mustang GT 5.0 runs great without the Air Conditioner on. With the AC on it often dies when I come to a stop. The idle is usually at 700 rpm but drops to 550-600 when I turn on the AC. Also, I can notice power surges while driving at steady speeds, again, only while the AC is on.
I cleaned the idle air control valve and the problem is still there. Do I need to replace the control valve? I've recently replaced the PVC, plugs, cap, rotor, fuel and air filters, as well as the battery cables. Although these parts needed replacing they did not help the unstable idle with the AC on. Can you help me?
Your map sensor may also be malfunctioning. It seems, since you are also getting a problem while driving with the A/C, that the car does not recognize the increased load of the A/C. The MAP (manifold air pressure) sensor is what tells the motor how much load the engine is seeing.
Bob, The Auto Answer Man
Have a car care question? Visit our automotive center and see if we've already answered it or a similar question.
Also in Home
- Sell my house? Or buy a new one first?
- DIY wall décor
- Home upgrades - Smart projects vs. costly mistakes Video
- Putting your lawn mower to bed for the winter
- Give your bathroom an inexpensive makeover
- First-time home buyer's how-to
- Combating carpenter ants
- 5 ways your house can make you go broke
- 5 simple and affordable luxuries for your home
- How to keep your mortgage data safe from hackers
- 5 home renovations that can raise your insurance rate -- or lead to discounts
- The right way and wrong way to pay down your mortgage
- 6 cheap, effective home security solutions
- 3 ways (and 1 reason) to refinance a HELOC
- Flood insurance too high? You may have options
- Should I refinance my home equity line?
- Find the best mortgage rates in your area
- 3 ways to use a mortgage calculator
- Mortgage calculator: Calculate your payment and more
- Home equity calculator: HELOC vs. line of credit
- Mortgage refinance break-even calculator
- How much money can I borrow for a mortgage?