tom3

First sorry for the multiple posts, I went through several iterations of tests, etc and I was posting as things went which was pretty confusing.

Now I have the data from the computer.

Symptoms:

Around 6k rpm the car feels like it hits the rev limiter and sputters
From 5k and above, it feels like it's lacking power big time

Facts:

3 spark plug wires are burnt, I can not change them right now, I am waiting for some parts
The tuning was done pretty lean and worked perfectly when I was living in HI. The car was recently shipped back to CA (humidity is very very different)
I am not sure if you're familiar with the noise sewing machines do, but that is how my valve train sounds (I think there is a light tapping though)
I removed the MSD because I had lots of missfires with it; I assume stronger sparks meant more arcing with the wires

Log1, at WOT

RPM Left O2 Right O2 Adv Ret Knock
3950 897 892 41 0 1384
4150 963 892 41 0 1384
4275 977 875 40 0 1384
4525 950 857 38 0 1384
4775 804 821 38 0 1384
5050 715 813 38 0 1384
5350 635 799 39 0 1384
5325 519 684 39 0 1384
5525 346 164 39 0 1384
5775 293 733 39 0 1384
6025 275 107 39 0 1384

As you can see, the O2 values are getting ridiculously low.
There is NO knock (the sensor works).

btw, injectors go up to 19ms pulse time on this log.

Both banks are the same way, so I assume it is not bad injectors, valve float, etc.

Fuel pump and filter? I would get lots of detonation. There is nothing on the sensor and this is not how the car sounds anyways.

Could the ignition system give up and not burn the fuel? but then why would it climb to 6k and gett progressivly worse?


Log2, at WOT

RPM Left O2 Right O2 Adv Ret Knock
3950 773 386 21 15 10720
3925 799 839 21 15 10720
4050 755 773 23 15 10720
4225 462 639 23 15 10720
4300 306 653 23 15 10720
4425 568 213 23 15 10720
4525 586 728 23 15 10720
4650 369 555 23 15 10720
4625 337 790 23 15 10720
4875 519 475 23 15 10720
4975 395 209 23 15 10720
4800 133 67 23 15 10720
5025 107 84 23 14.5 10720
4775 959 910 30 9.4 10720
4325 968 901 31 8.8 10720

This one makes even less sense to me. I did it in a gear too high, in order to slow down the rpm increase, hoping to get more data. As soon as I pushed the throttle, the knock / retard appeared; Yet there is no more knocking, etc through the whole log, so no detonations, even with really low O2


I am leaning toward the ignition giving up at some point, but I could be completly wrong.

Any idea welcome, I am really getting lost there. Unfortunatly the movers have all my stuff, I do not have tools, etc. I can read / write the computer if needed though.

drop top steve

The first thing I would do is get new wires on the car, then check fuel pressure, 42-43 lbs@0vacuum. If you have more than 10k on the fuel filter change it.

Injuneer

The logs are corrupted, or at least skewed to confirm the misfires. The O2 mV's are going down because of the unburned air from misfires - probably not from the mixture actualy leaning out. You can't make any progress on this until you fix the known problems.... you're just wasting your time until you fix the wires.

tom3

this is also what I was leaning toward (known ignition problem and 100mv o2 with no detonation)

I'll fix the wires, just waiting for parts...