Spark Problems 94 Gt

Discussion in '1994 - 1995 Specific Tech' started by Vapor20, Oct 9, 2013.


  1. Vapor20

    Vapor20 New Member

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    Pulling my hair out can't figure this out. 1# cylinder has no spark with the spout out, and spout in 1# has spark but #3 & #8 have no spark. Replaced TFI module, put a new pip in last year. Any ideas? Bad Pip? thanks
  2. Noobz347

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

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    @jrichker

    He might have some insight on how your symptoms interrelate.
  3. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

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    Dump the codes, watch for code 14 which indicates a PIP failure.

    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 Equus - Digital Ford Code Reader (3145) – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30-$36.
  4. Noobz347

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

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    Then there's this: http://www.gadgetsgalorestore.com/productid.php?id=137

    They're cheap, work very well, can be had at Walmart and most auto parts stores, and take less time. IMO, everyone who owns a fuel injected Windsor, should have one.

    JR's post mentions it but this is an up to date link.
  5. toyman

    toyman SN Certified Technician

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    On the 94-95 the DTC port is on the passenger side between the strut tower and firewall. This is a current reader link. Also, the codes are 3 digits on the SN95's.
    Noobz347 likes this.
  6. Noobz347

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

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    Same reader. :lol:
  7. toyman

    toyman SN Certified Technician

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    Just less expensive if $2 means anything. Leastwise, we're all on the same page.
  8. Vapor20

    Vapor20 New Member

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    thanks for the advice I'm going to start working on it again this weekend. i've done the paper clip trick before, i didn't realize the codes could still be present if the check engine light was not on. Was showing codes before but i replaced the maf(with 90mm lighting), also put a sct chip in it so maf would work.

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