nooby chick from Kentucky

greyfox69 said:

Any idle/stall problems? car idles fine and doesnt stall out but when at idle if you rev engine you hear a noticable cut out and an occasional backfire. see vid below for idle and rev...

Does the miss/surge occur at high speed or low speed or both?
miss/surge dump...happens at high rpms when on the throttle while changing gears. if you drive and change at low rpm it isnt as much of a cut out. If you are are at high rpms it is almost like the car completely stops for about a second then kicks on in.

Does the miss/surge occur when the car is cold or hot or both?doesnt matter hot or cold it will dump out at high rpms or when u rev engine.

Now something I did notice on further inspection today. The sensor plug that should be connected to the airbox/intake..is simply hanging not connected to crappy intake. I havent taken it to see if its throwing codes yet but seems to me that should be plugged in somewhere??
[end quote]

The airbox does not have a sensor - it is probably the wiring connector for the purge solenoid for the carbon canister.

Dumping the codes will help spot things that set a warning in the computer but don't necessarily set the Check Engine Light (CEL)


Dumping the computer diagnostic codes on 86-95 Mustangs

Revised 26-July-2011. Added need to make sure the clutch is pressed when dumping codes.

Codes may be present even if the check engine light hasn’t come on, so be sure to check for them.
Here's the way to dump the computer codes with only a jumper wire or paper clip and the check engine
light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp
or Check Engine Light and count the flashes.

Post the codes you get and I will post 86-93 model 5.0 Mustang specific code definitions and fixes.
I do not have a complete listing for 94-95 model 5.0 Mustangs at this time.

Be sure to turn off the A/C, and put the transmission in neutral when dumping the codes.
On a manual transmission car, be sure to press the clutch to the floor.
Fail to do this and you will generate a code 67 and not be able to dump the Engine Running codes.





If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method.
There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires
the self test connector.

89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.

The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires
as the self test connector.

WARNING!!! There is a single dark brown connector with a black/orange wire.
It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector.
If you do, you will damage the computer.

What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal
workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11
and you have some wiring problems. This is crucial: the same wire that provides the ground to dump
the codes provides signal ground for the TPS, EGR, ACT and Map/Baro sensors. If it fails, you will have
poor performance, economy and driveablity problems

Some codes have different answers if the engine is running from the answers that it has when the
engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Dumping the Engine Running codes: The procedure is the same, you start the engine with
the test jumper in place. Be sure the A/C is off, and clutch (if present) is pressed to the floor,
and the transmission is in neutral. You'll get an 11, then a 4 and the engine will speed up to do
the EGR test. After the engine speed decreases back to idle, it will dump the engine running codes.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

Alternate methods:
For those who are intimidated by all the wires & connections,
see Actron® for what a typical hand scanner looks like.
Normal retail price is about $30 or so at AutoZone or Wal-Mart.

Or for a nicer scanner see http://www.midwayautosupply.com/p-7208-equus-digital-ford-code-reader-3145.aspx–
It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.

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