Finally cranked it over, no spark, code 18

I've been battling with this engine swap for a while now. I finally got to where I could start it today and cranked it over. It didn't start, I'm getting fuel but no spark. I ran the engine codes and the first set gave me code 11 while the second set gave me code 18. Now the engine hasn't been started yet so that code 18 is from cranking. I looked up the code and it means irratic tach signal, or ignition issue of some sort. So everythings adding up.

Where should I start looking for the issue? Before putting the harness in I checked all wires and everything was good, even the resister. The coil is getting battery voltage when in RUN and START.

Any direction is appreciated. Oh, and any chance this could be a TFI issue? I have 2 that I tried but both were junkyarders. I might take the one off my 90 5.0L and see if that's the issue. Kinda just looking for direction or any help.

P.S. Sorry, this is a 78 Mustang II with a turbo 2.3 and 85 Turbo coupe wiring harness and PC1 ECU.

try the ignition module. My car died going down the road about a month ago and gave me a day's worth of trips to the part store trying to figure it out. It was cranking and all of the lights/accessories still worked so I tried the coil, distributor cap, distributor rotor, and, finally, the ignition module.

I have one fro my GT I'm planning on trying. I'm just curious if anyone has ever had that code before. It also suprised me that codes got thrown during cranking, but I'm thankfull that it did.

BTW, my batterys dead now

KOEO can be stored without the engine running, be glad it stored a code to give you somthin to work with... ignition module like everyone said so far would be a place to start

Update: I put the ignition module from the 2.3 on my 5.0 and it started up no problem. On the 2.3 I didn't have any dielectric grease to put on the module, couldn't find my damn tube. When I put the module back on the 2.3 I got a spark. It was a very weak spark, but that's either because my battery was pretty dead, or the fact that I painted over the dist cap terminals and spark plugs and just sanded them off. Their old units anyways so I'm just going to replace them and see what happens then. Oh and get my battery charged.

Would lack of dielectric grease keep the module from working properly, or did I just not notice that they were sparking just very weak?

FastMonkeyWheel, the dielectric grease is there for a heat sink, to keep the unit from overheating and to prolong it's life. It wouldn't have anything to do with the strength of the spark.

Even though the ICM started your 5.0, it still could be bad. Those things often get weak and act erratically.

Code 18 is 'Loss of TACH signal to ECA/electronic control assembly', so you're indeed on the right track......

Wow, I'm really getting ahead of myself. I also just realized that I forgot to hook up the engine to chassis grounding strap. I'm not sure if that's going to cause my problem, but it's something that needs to be there anyways.

The ICM gets 5 wires:
an input when in RUN;
an input when in START;
an output for the coil that is also hooked into the ECU's line to the coil, only after the resister;
an ignition ground going to the ECU;
PIP;
SPOUT;

I know the spout circuit has a removable plug wired inline to break the circuit when setting base timing. So is this what controlls the ICM to adjust timing? If so, how does it do it (just for curiosity's sake).

What's the PIP for?

I'll have my TFI checked at NAPA tomorrow and replace the plugs, cap, and rotor (wires are new), add the grounding strap, and recharge my battery. Then I'll double check all my TFI wires and make sure their all wired correctly.

Here's a good read on the PIP and SPOUT stuff:
Ford DIS/EDIS
Let us know how it works out. Good luck.

EDIT: Oops, I think you've got a distributor; anyway that link still describes the PIP and SPOUT signals, only the number of coils is different (1 vs 2 or 3).

My Ford EFI manual had the information, I just didn't do my research before asking for help.

FYI, the PIP sends a square wave to the ECU as the hall effect sensor passes through vanes in the distributor, this lets the ECU know how fast the engine is going and where in the crank shaft rotation it is. The SPOUT (SPark OUTput) is a signal from the ECU to the TFI module to adjust timing. There is also another circuit that runs from the TFI to coil wire, through a 22k ohm resister to the ECU to let the ECU know what the TFI is doing, this way the ECU can help diagnose if the TFI module is doing what the ECU is telliing it to do.