Scott's 4.9 Formula

[Fierofool]

As I understood it, if the wires had been removed from the cap and moved over 1 terminal, it ran.  I'm not sure why everything that's supposed to indicate timing like the mark and TDC wasn't productive. 

Initially, the chip that Steve provided didn't seem to make any difference.  After adjusting the timing, the car seems to run better with Steve' chip than with the one that was in the ECM.  He said for the time being, it would remain. 

[Wreck It Ralph]

It was advanced 360°? I'm not sure I understand what you mean by "distributor being turned one full cylinder"

Inquiring minds want to know. 🤷🏻‍♂️🤷🏻‍♂️🤷🏻‍♂️

[Fierofool]

I'm guessing if it was just 1 position it was 45° off or thereabouts.

[scottb]

Which way did they move the wires? I had the distributor moved 1 tooth in either direction, nothing looked like it was lining up correctly

[Fierofool]

They didnt move the wires.  They rotated the distributor the equivalent.  The distributor will be pulled to sealing the teeth and the distributor will be put back in its proper position.  No wires are or will be relocated..

[scottb]

I'm really confused now....... if they didn't move the wires how did it run?  A couple of replies up you said they moved the wires

[Fierofool]

Poor explanation.  IF the wires were moved 1 post.  They rotated the distributor to achieve the same effect.  They couldnt rotate it any further because the wires weren't long enough. The solution is to put the distributor housing back in the proper position, lift it out and reposition the shaft 1 or 2 teeth as required. That should put everything in or close to factory position.

[scottb]

Been there, done that........ check the videos I sent you

[Fierofool]

October 4 Report:

I  managed to "tune" it so that it works better on the original PCM. The
curious thing is, when the jumper is in, tuning goes perfectly "by the
book". But when the jumper is out, the timing is way off, and it can
only be tuned "by ear". I still don't know why that is.

I went on a longer test drive, and the SES light came on during the
drive. My scanner said "24 -- cannot determine vehicle speed". I cleared
it, but I figure it will come back on the next drive. Maybe Raydar knows
how to hook up the VSS.

I think there's a slight miss -- not sure. I got some Sea Foam and put
some (not all) in the tank. I'll see if it makes a difference on the
next drive. That will be tomorrow, because work and school traffic is
out now.

[scottb]

VSS may not be plugged in...... if it's not, oops

[Wreck It Ralph]

Scott. If you are still thinking of selling… I may now be interested. 😂

[Raydar]

October 4 Report:

...
I went on a longer test drive, and the SES light came on during the
drive. My scanner said "24 -- cannot determine vehicle speed". I cleared
it, but I figure it will come back on the next drive. Maybe Raydar knows
how to hook up the VSS.
...

Scott and I unplugged the VSS to check the wiring. Hopefully, it was plugged back in, at some point.
The reason for the code is that the ECM is looking for a later (magnetic?) VSS at ~24000 pulses per mile. The Fiero Getrag supplies a couple thousand pulses per mile, but the signal, if it can be seen at all, is NOT what the Caddy ECM wants to see. The type of VSS, the waveform, and the number of pulses (peaks?) per mile are way off.
I was hoping that there was something there that the ECM could see/use, but it would appear that that's not the case.
(I think that if the ECM sees anything at all, it will be enough to stop the VSS code from setting.)
I can turn off the VSS code in the chip, but that doesn't mean that it will run exactly like it's supposed to. (Actually, I thought I *did* turn it off. But I'm not sure, now.)
The biggest issue will be stalling when coming to a stop, as soon as the clutch is pushed in. I can explain why, but I'll spare you, unless you want to hear.

Edit - Dakota digital makes an adapter that allows later trannies to work with earlier ECM, but I'm not sure if there is a "reverse" solution.
When Ed did these swaps, he removed the bulb from the Check Engine light. "Out of sight, out of mind."  |

2nd edit - I think this is the device that other people have been using.
https://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=1192/category_id=287/mode=prod/prd1192.htm
No guarantees, however.

Ignoring the ignition issues, does the car run okay? Does it stall when coming to a stop? If not, the Code 24 may be able to be ignored (and/or turned off, with whichever tune will run the engine better.)

[Wreck It Ralph]

I think they went back to the original pcm if I read correctly.

[Raydar]

I think they went back to the original pcm if I read correctly.

Yeah. I saw that.
If it doesn't stall when coming to a stop, Code 24 can be turned off, and everything else can be left alone.
Don't know why the original chip would run better. Nothing major was changed. A bunch of codes and VSS were turned off, and the idle speed was increased. That's about it.
But I can do whatever is needed/requested, regarding the chip.

[scottb]

It did the pull up to a stop sign and die thing with me