Code 18 help 1990 LX

[kornnutt]

About a month ago I was driving and my car stumbled as i was driving and picked back up and ran fine.Then it started do it regularly. Then I was driving and it just died one day and wouldn't start back and after sitting for 10 mins it started back up. After sitting for 8 hrs it wouldn't start then finally started. It runs pretty rough now and backfires when I let off the gas. When i start it dies immediately unless I pump the gas and then it will idle and then it will miss and run like crap and then die. Ive chaneg plugs, TFI , EGR, Air Bypass Valve. Im at a loss.I took it to 2 shops and still running bad. First guy check the spout and said it had a short and the other shop said no short. SO maybe its ECM?
Code 18 C. Ignition Diagnostic Motor Failure or Loss of Tach Input Diagnostics Monitor or Spout Circuit Ground
18 R Spout Circuit Open or Spark Angle Word Failure.

 

[jrichker]

Code 18 - SPOUT out or wiring fault - look missing SPOUT jumper, short to ground or open circuit in SPOUT wiring going back to the computer. Possible bad TFI.

The SPOUT enables the distributor to advance the timing beyond the base setting. Without a working SPOUT, you are locked down to the timing you set with the timing light.

Checking the SPOUT wiring
Tools needed:
DVM or Ohmmeter
10 MM wrench
Phillips screwdriver.
6 ft 16 or 18 gauge jumper wire with alligator clips on each end.

Anytime you make resistance checks, the circuit under test must not be powered on. If it is powered up during the test, your readings will be wrong and you may damage the meter. Do not touch the probe tips when making resistance measurements. If you do, your readings may be inaccurate.

Remove the SPOUT connector from the ignition harness by the distributor. Remove the passenger side kick panel and loosen the 10 MM bolt that secures the computer wiring connector. Use your DVM to measure the resistance between ground and pin 38 (yellow/lt green wire): you should see and infinite open circuit. Keep the DVM connected to pin 38 (you may need a helper at this point). Insert the DVM lead you previously had connected to the body ground into the computer side of the SPOUT connector. You may need some extra wire to extend the test lead, so have some 16-18 gauge insulated wire handy. If you extend the test lead, remember that the quality of the connections may affect your readings. You should see less than 2.0 Ohms: more than that indicates a wiring problem

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

Diagrams courtesy of Tmoss & Stang&2birds

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds
(website host) for help on 86-95 5.0 Mustang wiring Mustang FAQ - Engine Information Everyone should bookmark this site.

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http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

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Complete computer, actuator & sensor wiring diagram for 88-91 5.0 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Complete computer, actuator & sensor wiring diagram for 91-93 5.0 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/91-93_5.0_EEC_Wiring_Diagram.gif

Complete computer, actuator & sensor wiring diagram for 94-95 5.0 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/94-95_5.0_EEC_Wiring_Diagram.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif

TFI module differences & pinout
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif

Fuse box layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

 

[kornnutt]

No Fix about to burn the damn thing even swapped a new ECM in. Any other suggestions

 

[jrichker]

It is a problem with the wring or TFI, so get out your multimeter and be prepared to do some measuring.