2.3L ('83-'97) SPOUT CODE 18 after final assembly, last code to correct : SOLVED!!!!!

[corerftech]

Ill preface this, I know what SPOUT is and have already corrected a shorted SPOUT condition with a new Standard Brand DIS, a replacement coil (exhaust) and a wide variety of damaged wires by former owner BUBBA from Mississippi. But alas it has returned unexpectedly after I tampered with most of the front end.

I have had the entire engine bay apart, have corrected probably 20 damaged wires, a MAF issue..... all prior to Sunday reassembly.
I have had to do so much to trans/clutch/instrument panel/coils/plugs/cooling..... it was a horror show.

Tonight I finished assembly enough to test drive. 93 octane in it, fired it up and test ran in garage.
It threw a code 18 which hasnt been around for 3 weeks, since new DIS installed and all wiring corrected. That is the only code now and it wasnt there a week or so ago when I was posting about MAF faults.
Unlike prior test runs, it ran really well with MAF resolved and the engine back to bone stock form, stock intake system, OEM MAF, etc.

This is a 1990. I have had to reinsulate all wiring on black and grey DIS connectors due to faults (which corrected the code 18 prior).
I am an electronics tech, its really good work. There should not be a fault in SPOUT (there was a short right at shield entering connector).

I never traced the SPOUT from end to end and physically verified every inch in the bundle.
Ill add this, my tach was DEAD at start of repairs, replaced the DIS and tach began to work.
Tach now bouncing at times (like its stumbling when its not), but tach still works. That has been the case since the tach started working, has always exhibited a funky bounce at times.

Now I disturbed the entire main bundle from ECU to breakout branches due to removing and replacing the inner fender liners (in reversing bubbas hot rod format intake). Reassembly took a bit of work and I didint think I abused the big bundle.....

I have the EVTM in front of me and SPOUT is pin 5 on DIS module (correct me if I am wrong). EVTM shows Yellow/Lt Green (SPOUT) as PIN36 on ECU.
As far as I can see, the SPOUT line is direct from ECU to DIS with the test shorting plug in the middle.

IDM wire, PIN 12 on DIS drives the TACH.



As I understand, ECU sends new SAW to DIS over SPOUT, ECU gets confirmation feedback of the update by the IDM wire, which drives the tach as well.
That is the loop. SPOUT from ECU to DIS, IDM from DIS to ECU. Correct???

Is it possible the IDM wire has a fault that is causing both TACH BEHAVIOR and the CODE 18?

Or is the CODE 18 exclusive/absolute to a fault in SPOUT line from DIS through shorting plug to PIN 36 on ECU??

Also IS PIN 4, Dark Green/Yellow on ECU the IDM line?
It appears in EVTM if PIN 4 is the IDM, then PIN 4 is both DG/Y and BK/Y and has branches the feed the cluster and the tach svc connector.


So bottom line, can IDM faults case a CODE 18 or is it exclusive to SPOUT LINE and its end point devices (ECU/DIS)?

Thanks in advance for the help. My last issue. I could get the truck to stumble a bit but really had to seek it. Low end power (creeping in second gear lugging) was excellent. No stall, smooth, etc. First gear is similar. But every time I start, it backfires when it hits for the first spark (POP). It wasnt doing that prior to final assembly and surgery after the MAF correction. POP started with the revisit of CODE 18.

 

[franklin2]

The guy in the book I have has a long write up on the code 18. I don't understand it all, but he differentiates between a code 18 that you receive during a KOER test, and a memory code during the KOEO test.

If you get a KOER 18 fault, he says it's a hard fault and to check the normal things that you are checking. If you can't find a fault, he says to do the computed timing test in the supplemental EECIV tests. He says it should be the initial timing you set with the light, plus 20 degrees + or - 3 degrees. If this checks out and you still get a code 18 while doing these tests, he says the computer is not working correctly. If the computed timing was not correct, he says to check the initial timing again to verify it. He then says to check the voltages to the ECM. If all that checks out, he says to get a tachometer and hook it to the spout wire. He says it should read something greater than zero. If it's dead, check the wiring again, and if the wiring and connectors are ok, replace the ECM.

If you get code 18 as a memory code only, he says that there was a temp loss in the IDM circuit to the ECM. Besides the standard wiring checks, he says the ignition module could also be at fault. He then says you can set up the supplemental wiggle test, and start wiggling the ignition wiring and tapping on the ignition module and see if a fault comes in.

I did a quick summary of what he was talking about in the book. Here's the book I have.

Amazon.com

 

[corerftech]

That book pretty much recites what I find in the innova OBD1 tester manual.

my fault would be KOER, the 18 follows a 10 code separator.

I have no engine off codes.
And the behavior is consistent with the term “intermittent” and so in KOER mode any SPOUT defect would cause the Continuous Memory code 18.

I did find some evidence that the IDM line can cause the feedback loop to fault and throw an 18 so if IDM and SPOUT aren’t perfect and stable then either faulting will cause an 18.

That helps me understand where to examine for faults except a 5 foot long single wire!!!!

I saw your post on another forum and read the book except hut didn’t bookmark. Thanks for reposting here. It adds a bit more clarity.

 

[corerftech]

I will add this.
After ICM replacement, timing was checked and during the two minutes on my ECU (not Cardone reman that was sent back as it halted the tach from working at all and also ran like crap!) my timing was 30 degrees plus/minus, as it should be.

I take that as the SPOUT wire has a fault that is not severe but intermittent (of course I have not tested running since reassembly so maybe it is fubar now).

If it was fubar, it would be easier to shake out.

The book you have excepts from specify a digital tach and not an analog for SPOUT testing.

I only have an old Craftsman Dwell Tach (read: analog!). I expect it has too low an impedance and will likely pull the SPOUT line down if used.

Any insight there?

 

[franklin2]

I think I got mixed up. You are getting the memory code and not a hard fault like you said. So your theory of the IDM line goes along with what he said in the book.

Help me out here a little bit, I may learn something. So when the engine is off, but the key is on, and you get a code 18, that is the computer monitoring the voltage on the spout wire and it's out of spec? Like being pulled to ground or something? But with the code you are getting, that is a test for function, the ECM sends out a signal on the spout, and the IDM is a feedback line like you said and the computer takes the IDM info and verifies something about it to be correct or faulty?

If the above is true, just sitting there your spout wiring and connections are good as far as the computer is concerned?

 

[corerftech]

Per both your book and Innova, Ford EEC4 at startup for 2 mins sends a 20degree plus/minus3 deg adjust via SPOUT (normal path) thus allowing the operation of ECU advance to be tested, and detected for errors/faults over IDM. If IDM doesn’t detect the advance (20’) in the two minute run, then KOER test will show a code 18.

But if the engine runs perfect for 5 mins, hits the road, faults just once, code 18 persists in memory.
Code would be 11 (COMM ok), code 11 (separator), then code 18.
If at KOEO test a fault is detected (I.e., spout bar not plugged in), then code 11, code 18, code 10, nothing.

I have the condition of code 18 after an 11/10 which means at self-tes before startup the fault is not present but becomes present when engine is running at some point.

The fact that the SPOUT is short, direct but shielded means that the whole path from ECU to DIS could have an issue anywhere. Exhaust heat damage, etc. The way Ford directed wires at the shorting bar makes for high stress where the wires can be oil soaked, heat damaged, frayed, shrunk insulation, twisted and then have porosity and leaks to the shield.
The IDM is not direct, hits more nodes, but seems as though it may be suspect to a fault of misreporting.

That’s the logic I am using or will use. Ultimately, a faulty tach (unlikely) a rub, short or open, high resistance or a break that is acting temperature sensitive could develop a code 18 (on the IDM line). I didn’t follow or test the IDM and thus may have a secondary wire issue.

Then again, Spout may be the issue.

I didn’t like the fact that the Reman ECU from Rock Auto caused the tach to go dead completely after I installed a new ICM and had it working. Swapping back the tach worked again but——- was there a hard fault in the replacement ECU that caused a crappy start, dying shorty thereafter and a dead tach?

It’s been pissed off since the ECU test but may have been pissed off all along or got angrier at me for moving the wire harness as much as I have had to.

Thoughts? I’m pooped tonight from work but I might muster 30 mins to shake out the SPOUT again.

 

[RonD]

You are correct on how it works

But the ICM doesn't need the Engine computer to work, it can start engine and do RPM spark advance on its own
So disable SPOUT and see if engine starts and idles OK, if not then ICM is suspect
You can REV engine as well but it will be sluggish/slow going up, but once at steady higher RPM it will be OK

The SPOUT/SAW signal is the "vacuum advance"/Load advance needed for electronic ignitions

In distributorless systems the Crank sensor is set for 10deg BTDC, that's the PIP signal
PIP is the baseline timing the computer uses to time injectors and to calculate SPOUT based on engine load, i.e. throttle position and fuel mix

When SPOUT is enabled, yes you should see spark timing jump from 10deg BTDC to 20-25deg BTDC its an emissions thing, lol
If engine starts to run poorly with SPOUT enabled then wiring or computer issue
Effected wires can be PIP, SPOUT or IDM
There is also an Ignition ground wire, this wire makes sure the Crank sensor, ICM and Computer all have the same reference point for the signals being exchanged
And as we all know Grounds are a "bitch", lol, you can chase your tail for awhile checking signals(1 to 12volts) when the problem was the 0volt/ground connection

 

[corerftech]

I have been building vacuum tube amplifers for hifi use for almost 30 years. I have also spent many years repairing HAM gear and Antique Radios, and of course TUBE GUITAR AMPS.

What is the most important thing to focus on when there is a problem with a Fender Amp????

Wire layout!! Your either a HERO or a ZERO, feedback and oscillation or a stable amp.

So when I "fixed" the harness faults, I did great.
When I changed all the plugs, dealt with a failed coil, and reused the "slightly longer than needed" existing nice quality spark plug wires, I did what I did for 30 years of my professional life, I made a pretty picture with cabling.

The intake coil is in close proximity to the IDM wire.

Wait, ill start over. I tested opens, shorts and loop DCR on IDM and SPOUT. No faults, period. I freaked a moment when I tested the BLK/O shield in the grey ICM connector against the IDM wire, came up with 475k ohms. I then popped the tach off the panel and voila, an open circuit. NO FAULTS FOUND FROM ECU to final nodes.

Ok, back to the good part. As I was testing I realized that I had 30-50kVDC next to (and I mean up against! my IDM wire loom for the grey ICM connector. I wired everyone up after dressing Spark Plug wires toward the head and slack wire was moved well away from harness.

I cleared codes and fired it up. No 18. I rebuilt the loom for the grey/bottom ICM connector and left everyone flying above. Fired it up, no code 18. I then finished the lower section (coil input/radio cap/ICM grey), left all flying above, no code 18. I then finished the black/upper connector for ICM, dressed the wiring again to the main 1 inch loom, fired it up, no code 18.

While I was assembling (and before) I used a wood probe to move wires and I watched an analog dwell/tach on the fender skip beats pretty harshly with certain movements of the wires. That sealed the deal with an inductive leak. After assembly, you can beat the truck and it wont fault.

No it pops EVERY time I start it on a cold start. Like a supressor on a gun, the first shot is always louder than latter shots. Restarts are pop free. I ran the truck in garage only, played with throttle, nice smooth response up the ladder, no code 18. No code period. Just an 11, then a 10, then an 11........ hell yeah. Happy, Happy, Happy.

Spark plug wires were inducing errors in IDM and im sure distorting the waveform seen by ECU. Bad waveform, bad trigger, code gets dropped. Had I not been lazy and put my scope on it, Id have seen the buggered waveform. Not that it would have helped me..... the wood stick was the key to isolating it.

Oh, and I fixed the hazard flasher relay.........I havent touched everything in the truck yet but Im close. Bubba absolutely touched everything (molested is more fitting).

Moral of story, harness proximity to large signals is an issue for IDM and SPOUT. Both are only 4-8v waveforms and 30kV will easily induce that as a transient if too close. Poor computer...... I feel bad for it.


Many thanks for the input RonD and Franklin2...... the subject of the feedback loop in the book presented is what moved me to consider a fault in IDM and not SPOUT path.

Mike