Comments on: Ford 3.8L Idle Problem?

By: kimblegabbard

kimblegabbard — Mon, 28 Sep 2009 17:44:22 +0000

If it is a 1988 it has a 3.0 motor. Your problem is the mass air flow sensor. Most places will want to replace it and it will cost about 30..00. plus labor. You can probably get some one who is handy to clean yours with carb cleaner. That may stop your problem…if not replace the sensor. good luck!

By: Sarah S

Sarah S — Mon, 28 Sep 2009 17:44:22 +0000

It sounds like a vacuum leak. I’ve fixed a lot of vacuum leaks on Ford 3.8s in various models. The rubber elbows off the intake for the main vacuum line rot away. The problem is usually intermitent like that. Hope this helps you.

By: LeAnne

LeAnne — Mon, 28 Sep 2009 17:44:22 +0000

Possible concerns include EGR valve stuck partially open, MAP sensor, vacuum leak or a dirty throttle body.
Basic checks include all of the above and fuel pressure and a self test for fault codes.

By: Mike R

Mike R — Mon, 28 Sep 2009 17:44:22 +0000

The IAC is dirty (idle air control) it’s mounted on the side of the throttle, kind of a cylinder about 5" long and an inch in dia. 2 10mm bolts. use some carb cleaner. If you unplug it the idle should settle down to one speed and stop hunting.

By: Ryan M

Ryan M — Mon, 28 Sep 2009 17:44:22 +0000

The 3.8 was not available in 1986, the first year of the Taurus. I believe the 1988 model year 3.8′s were unique because they lacked a balance shaft. There’s a good chance you need a new Idle Speed Control Valve (it’s on top of the throttle body; Mass Air Flow sensors were not on the 3.8 until 1990 or ’91), but that part will cost $138 from a dealer, so you may want to do some other diagnosis before taking your chance with that. You should start by either visually inspecting the spark plugs and then scanning for KOER codes, or vise-versa. 1st tip: OBD-I Ford computers can be scanned 2 ways: Key On Engine Off or Key On Engine Run. There have been several times when I’ve scanned my computer in KOER mode and discovered codes, even though my check engine light wasn’t on. The KOER codes didn’t seem to turn on the MIL, and that could be the case with your car too. 2nd tip: The 3.8′s had aluminum heads on an iron block; these dissimilar metals expand and contract at different rates, and gasket technology in the 80′s couldn’t last much longer than 60k miles, but Ford has newer gaskets that will prevent coolant leaks into the cylinders. Checking the plugs will let you know if combustion is even in all cylinders, or if one cylinder is fouled with oil or coolant. 3rd tip: It’s common for the power steering pump to leak fluid, which drips onto the wiring for the front O2 sensor and causes a false trouble code (74 I believe). If your car is leaking ps fluid, replace the o-rings and fill with type F fluid. The small o-ring has to be a metric size, which I believe is 8mm, and you can probably buy just one at ACE hardware.