Engine Help: 93 5.0 - No Timing Advance - Code 18 (r)

Discussion in 'Fox 5.0 Mustang Tech' started by Moostang, Mar 15, 2014.

  1. Hello all. I have been troubleshooting a problem with my mostly stock 93 5.0 for a couple of months now and am highly frustrated. I just cannot find the problem.

    93 For Mustang 5.0 V8 - 170k Miles - Mostly Stock
    Original Engine - Block/Heads/Intakes (upper/lower)
    Original Exhaust
    Original EEC

    Primary Problem:
    Timing does not advance at idle or while revving up the engine. SPOUT in or out does nothing.

    EEC Codes:
    KOEO: Code 11 (o,c) - system OK
    KOER: Code 18 (r) - SPOUT circuit open
    The Check Engine Light is NOT on.
    EEC Cylinder Balance Test - 90 - system OK

    Aftermarket Engine related mods before the problem showed up:
    Upgraded alternator
    Additional alternator wire - alternator to battery
    Upgraded ground wire - battery to engine
    Dual Electric Fans and Fan activation Thermostat
    Upgraded water pump
    Upgraded Radiator

    All of the above upgrades were performed 6 months+ before I noticed the problem. After the problem showed up I started troubleshooting and decided I would go ahead with some planned upgrades and maybe get lucky with resolving the problem at the same time. (I was wrong :( )

    Aftermarket Engine related mods after the problem appeared:
    New Idle Air Bypass (IAB)
    New Throttle Body
    New EGR Plate
    New Cold Air Intake
    New Throttle Position Sensor (set at .95)
    New MSD Coil
    New MSD Distributor, including new PIP (timing set at 12 degrees)
    New TFI (came with Distributor)
    New NKG spark plugs
    New MSD spark plug wires
    New vacuum hoses
    New PCV
    Other troubleshooting:
    EEC connector pin 36 to ground = infinite resistance
    EEC connector pin 36 to TFI pin 2, SPOUT in = less than .6 of resistance
    EEC connector pin 4 to TFI pin 5 = 22k resistance
    TFI pin 5 to Coil negative = less than .5 of resistance
    Unscrewed both EEC grounds, sanded, cleaned, and remounted

    I bought new O2 sensors but could not for the life of me get the old ones out even using an O2 wrench so I returned them. I plan on installing a new exhaust next year so I'll replace them then since the EEC showed no codes referencing the O2 sensors.


    Secondary problem: (this may be related to the primary problem)
    From a cold start, the engine idles fine for about 2 minutes then starts to surge while idling until the engine eventually dies. If I adjust the manual idle screw by about 1/4th of a turn to increase the base idle ~200-300 RPMs then the idle stabilizes.


    Any help would be appreciated.
  2. Code 18 - SPOUT out or wiring fault - look for short to ground in SPOUT wiring going
    back to the computer. Possible bad TFI or defective 22 K resistor in the IDM wiring

    Use a timing light to check the timing: remove the SPOUT and observe that the timing retards at least 4 degrees. Put the SPOUT back in place and observe that the spark advances at least 4 degrees.
    This code can disable spark advance and reduce power and fuel economy.

    Remove the passenger side kick panel and disconnect the computer connector.
    There is a 10 MM bolt that holds it in place.
    Disconnect the TFI module connector from the TFI and the measure the resistance between the yellow/lt green wire and ground.
    You should see greater than 100 K (100000) ohms.
    Check the resistance from Pin 4 on the computer connector (dark green/yellow) and the dark green/yellow wire on the TFI connector. You should see 20-24 K Ohms (20,000-24,0000 ohms). The resistor is located in the wiring harness about 6” from the connector. You will need solder and heat shrink to replace the resistor if it is bad.
    Next measure the resistance between the yellow/lt green wire on the TFI module connector and Pin 36 on the computer connector. With the SPOUT plug in place, you should see less than 2 ohms.

    The following is a view from the computer side of the computer connector.

    This diagram is the wire side of the computer connector.

    Diagram courtesy of Tmoss & Stang&2birds

  3. Thank you for the reply. What I quoted above is the only thing you listed that I have not tried yet. I did do this from the Computer connector, just not the TFI connector. I'll try this when I get off work this afternoon.
  4. OK so I tested this and got infinite resistance which according to your post is normal. I had already performed all of the other items in your post.

    Next? :)
  5. MSD distributor and TFI? Feh. Swap in a stocker and see if that fixes it. I only use FOMOCO TFI's and stock distibutors in my Mustangs. MSD equals My Spark Died.
  6. I upgraded the distributor after the problem started, i.e. the problem still occurred on the stock distributor too. The TFI on the original distributor was only about a year old as well.
  7. That doesn't leave much else but the computer. If you are very brave or highly skilled in fixing electronic stuff, you can open the computer case. Look for burnt traces on the computer PCB and for capacitors that are budging or show signs of leakage.
  8. Thank you for the reply. I've successfully soldered capacitors on LCD monitor circuit boards before based on a web article which was pretty easy but actually troubleshooting electronics on my own (without a guide) is beyond my abilities. However, looking burnt traces or for bulging capacitors is easy enough.

    Also, if I take the EEC out would a Ford dealership be able to fully test it? Anyone know?
  9. Can they? Yes if they have the Rotunda test equipment. Will they? You'll need to call and find out and see what the cost is. Autozone and PepBoys sell reman EEC's for about $135- at least they used to . They may have the test equipment there as well. Most good auto shops have what's called a break out box that they can hook up to your computer and it will read it for you.

    Also check out this site. Very good informaton

    Moostang likes this.
  10. Wow, that I didn't know. I frequently shop at autozone but did not think for a moment that they'd have an EEC. It's far cheaper than the others I've found too! Thank you!!!!

    As far as fordfuelinjection.com, they've been down for the past ~week.
  11. Humm, Autozone does not show the Calibration codes such as C3W. It only shows a partial F3ZF number.

    For instance, my EEC shows F3ZF-12A650-FA but Autozone only shows "O.E.M. F3ZF-FA". Anyone know if that is the same along with the same Calibration code?
  12. That sounds like a very interesting proposition. Check out the comments and survey results and see how well they do.
  13. Yes. That should be the correct eec. Check oreilly they have all the eec's listed for your year.
  14. Thanks everyone. I'll order another EEC tomorrow and let ya'll know once I receive/install the new one.

    Edit: there goes that idea. Both Autozone and O'Reilly's show unavailable when trying to purchase online. :(
    #16 Moostang, Mar 18, 2014
    Last edited: Mar 18, 2014
  15. Call. They can usually track one down. They did for me.
  16. AZ and OR. both said back ordered at the manufacturer. However, I googled the part number since it was the same for both AZ and OR and found it at some random auto parts place I haven't heard of before, and for about 10$ cheaper.

    Hopefully, this will be the end of my timing problem.
  17. Update: I swapped out the EEC during my lunch break today and that resolved my timing problem. It is now advancing normally woot! I also reset the base timing. It's purring like a kitten.

    After work I'll have more time to reset base idle (had it high for the surging idle) and set the TPS properly. I'm hoping this resolved my surging idle too but we'll see.