My 1989 Ford 250 (351W) is shooting out 5 codes still and the electrical guy I took it to is a douche and wont shoot me straight because I didnt want him to do the repair for it...so, here is my question.

The major codes I am worried about are 63 and 18. According to www.fordfuelinjection.com, code 63 refers to a low voltage in the throttle positioning sensor. Does this mean the sensor is bad or is there a more difficult issue such as a short in the wire leading to this sensor?

Also, code 18 (my biggest problem) refers to a circuit failure in the IDM or the SPOUT connector is grounded. This is a problem because I can not even set the timing with this unsolved problem. Anyone know where to start with this? I am about out of options and I am a dunce when it comes to wiring. Would it be better to find a whole new wiring harness from somewhere and start over?

 

Use a DVM to check your TPS voltage. Code 63 indicates the TPS out signal is or intermittently below .6 VDC. Most TPS sensors are not adjustable. I would suspect a PO has jacked with the idle stop screw if your TPS is on the edge of being too low.

Code 18 can be caused by a missing SPOUT connector as well as poor connection. Another common cause is the wires leading to/from the connector wear through to the foil shield which in turn grounds the signal. It is not that bad of a job to check for these with a DVM.

 

Thank you so much!

OK, so in relation to the TPS circuit, should I replace the whole sensor itself to fix this problem?

In relation to the SPOUT problem, I tried both leaving the connector in and removing it, and that has no affect; so, your theory of the wear to the foil shield sounds valid! Where may I be able to find this "foil shield"?

 

I would not replace anything until I verified what the signal value is. Invest in a Volt/Ohm meter to measure it yourself. Harbor Freight has several cheap models available.

The foil shield is covering the wires to/from the Ignition Control Module (ICM) as well as the SPOUT circuit.

Could you clarify what "I tried both leaving the connector in and removing it, and that has no affect" means? What is the problem you are trying to resolve? Again with a meter you can measure if there is a short to ground in the SPOUT/IDM circuit.

A Code 18 can also be self induced when setting the base timing by removing the SPOUT. Another cause of DTC 18 is installing the wrong Ignition Control Module (ICM). Let's make sure this is a real error code.

 

I tested the KOER for the code 18 both with the SPOUT connector plugged in and with it disconnected. The code was given both times it was tested. I did this thinking that there was something with the SPOUT connector or that circuit. I am not sure what was supposed to happen, but there was no change in that. It was giving me a code 18 even before I messed with anything in the ignition area. I just played around with it to see if there was anything I was missing.

I do know that out of 6 wires coming from the ICM, there was 1 wire that did not have a value whatsoever, but that one was the number 4 wire running a split between the ignition relay and the ignition ground in pin slot 16 to the ECM. Should I be concerned with that?

 

Let's get a handle on what tests are revealing the code 18. When running the tests the first portion is KOEO. If there are no codes you will get 11 pause 11. If there are codes, each will be displayed twice. The next set of codes to be displayed are from Continuous Memory (CM). From there the KOER tests are performed, which do require user input for some of the tests to pass.

At what point are you getting code 18? If it is from CM the code means there is an IDM circuit failure or the SPOUT circuit is grounded. If code 18 happens during the KOER test it means the SPOUT circuit is open.

I would suggest you determine which tests are displaying code 18, then clear the codes. Then I would drive the truck 30 minutes for a normal drive cycle then recheck the codes.

Just to verify if there really is a problem with the SPOUT circuit what is the timing running at with the engine warm, at idle and the SPOUT connected? What is the base timing setting at with the SPOUT removed?

What started this whole scenario? Was something replaced?

 

Im pretty sure the code flashes at the KOER portion. It only flashes a 31 with the KOEO and I am not sure what to look for to find the CM code, so thats how I narrowed it down.

The thing that started all of this was the fact that the front fuel tank was not working at all and I have already replaced the fuel filters and the fuel pump in the front tank. I even had the selector switch tested as well. There is low voltage running somewhere between the switch and the pump causing it to not pick up the fuel from the tank. You can hear it switch on when you turn the key, but not enough to do its job. I got to thinking about it and started to check the codes to see if there might be a connection between the codes and the low voltage to the pump - and sure enough...3 or 4 of the 5 were low voltage codes. Of course I was also interested in why the truck was still running a little rough because I had already tried to replace the plugs, wires, cap, rotor, and even a manifold because I thought that the cracked one that was on it was causing it to run rough. After all of that, it didnt help it one but at all, so I looked into seeing if there was a timing issue; but when I found the code 18, I found it impossible to correctly set the timing at all with it like that until I could get that SPOUT issue figured out. So thats what started the whole project.