Need Help Plz

Discussion in '1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-' started by ZSD1989, Jan 14, 2014.


  1. ZSD1989

    ZSD1989 New Member

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    Hi guys I am having a problem with my 88 four cylinder manual mustang I have replaced just about everything, fuel pump, fuel filter, map sensor, o2 sensor, tps, coil, fuel injectors, ok now for what the problem is when it idles fine but when you try to drive it after it is warmed up the throttle drops to the point of stalling out unless I push in the clutch to where it idles and then it fine until you try driving again and then it does the same so im hoping someone can help me out I am out of ideas
  2. madspeed

    madspeed Colonel Mustard Mod Dude Founding Member

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    pull codes
  3. Noobz347

    Noobz347 Stangnet Facilities Maint Tech... Er... Janitor Admin Dude

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  4. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

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    Dump the codes: Codes may be present even if the Check Engine Light (CEL) isn't on.

    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.

    [​IMG]

    [​IMG]

    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.

    [​IMG]

    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.

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

    [​IMG]

    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.

    Your 86-88 5.0 won't have a working Check Engine Light, so you'll need a test light.
    See AutoZone Part Number: 25886 , $10
    [​IMG]



    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 www.midwayautosupply.com/Equus-Digital-Ford-Code-Reader/dp/B000EW0KHW Equus - Digital Ford Code Reader (3145It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $22-$36.
  5. ZSD1989

    ZSD1989 New Member

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    What if no codes show then what
  6. madspeed

    madspeed Colonel Mustard Mod Dude Founding Member

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    you're screwed
    88LX5.Oh and 84Ttop like this.
  7. ZSD1989

    ZSD1989 New Member

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    What about replacing the computer
  8. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

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    No code 11 (two flashes when the computer dumps the codes)? A perfectly functioning system will always get a code 11, it is the everything is OK code. The 11 code is computer passed its internal self test.
    If you don't get an 11, you have computer or wiring problems.
    Please check and repost.
  9. ZSD1989

    ZSD1989 New Member

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    ok so I ran the test and I got the code 11 but I also got code 34 not sure whats up with that so any ideas

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