This thread is a mess, but OP needs to start by getting the scanner working. Sounds like you may have a ground problem.

 

You didn’t answer the question about how you can read your digital gauge when the PCM goes into closed loop. Does the gauge reading start to jump around about 4 minutes after cold start, and with the coolant temp above 140-degF?

If the A/F ratio numbers aren’t changing rapidly, even at idle, it’s possible the PCM isn’t going into closed loop. If it stays in open loop, the PCM can’t correct for the lean condition. If it was in closed loop, the PCM would see the lean O2 sensors and richen the mixture by increasing the long term fuel trims (LTFT or BLM's) until it got the A/F ratio back to 14.7:1. But that's not happening. All this would be easy with the data log.

Just how “white” are the plugs? Modern EFI systems don’t seem to produce the coffee brown plugs the carbs did. Look at the NGK plug site for their spark plug color chart. And how do we know the O2 sensors are healthy, or that the digital gauge is accurate? Do you have any evidence of knock retard with the engine under load? Do you hear any knock with the engine under load?

The PCM is programmed to achieve 14.7:1 because that is the A/F ratio that produces minimum emissions (total of HC, CO, NOx). The engine could achieve better fuel economy with an A/F ratio of perhaps 15.8:1. But that would increase the formation of NOx.

 

I agree that i need to get my data logging. I have checked my grounds and added additional ones to ensure thats not the problem. I have even tested all my cables individually for a shorts, voltage and resistance. Ive changed out ecms. I have changed out opti’s, ive changed out coils and plug wires. Ive chaged pc with different operating systems. I bought a new battery. Still, no luck in getting it to go away.

 

Sorry I didn’t answer your question. I can tell you that most of what your inquiring about is hard to answer without you speaking directly to me or being here to see the changes your asking about.

Ill take a video of the digital readout. Post it on here to help you see what i see.

Short of using a multimeter (to monitor o2 sensor voltage) while i am running down the road, ive had to revert to the way you would tune a car in the 60’s. Go down the 1/4 mile, see your time, make a change, see if it improves. Rinse and repeat.

Thats why i am looking for the setting to just run a little richer in my tuning.

 

If you can't reliably datalog, how are you going to reliably change the tune?

Where are you located? Maybe somebody nearby can help you debug your logging toolchain.

 

I can still flash my ECM, as for how reliable, im not sure. Trial and error i suppose.

im located in palatka fl.

 

I've asked GaryDoug if he could look into this. He's in FL.

 

Have you tried different programming cables?

Off the wall question....do your lights pulse at night? Have you checked the AC level at the battery? With the car running, take an AC voltage reading at the battery. If something is screwed with the alternator rectifiers it can cause AC to ride in on the DC which can cause all kinds of strange voltage issues.

If you know how to use an o-scope, it would be best to look at how clean the voltage signals are with it.

 

Using direct emails, I suggested the same but I doubt he has an O-scope. I would guess it is operating borderline; working, failing, then working again.

I also suggested unplugging the other modules on the bus.

Also, he is using a pc with Windows XP. The latest version of scan9495 is not always compatible with XP. Unfortunately program that has the 93 year is only in the later versions. In this case, I now suggest he uses a newer operating system like 7 or later. I probably would not risk the purchase of a new pc expecting this to work. Maybe borrow one for a while first.