There may have been alot of carbon build up. In addition to the cpi spider causing running rich, when I bought I almost didn't get it home to running extremely rich from dead O2 sensor. I did...

Which ones are you asking about? I think I've tried to check most. I don't find any vacuum leak, the spider injector assy and nut kit have been replaced. New dist, plug wires, cap, rotor. All...

It is CPI running stock advance (only temp changes made during test logging).
The range of the knocks are in the 1600 to 3200 rpm cells, map of 95 to 100.
I did try reducing "Main Spark Table...

I have stared at the logs for hours and can't see any correlation of the hesitation. I believe the cts is good. I have pulled it and put in in a pot of water along with a thermometer, all good. ...

I do have the VE table set up pretty well. It has a MAP sensor. Is there a corresponding table for the MAP that I should be paying close attention to?

Hi All, I have a 1994 Sonoma 4.3L vin w with a intermittent hesitation with moderate throttle in the 1500-2800 rpm range. Bought used with many issues and am mostly down to this hesitation and some...

Yes, I had issues after I upgraded my win7 to win10. TP ran, but my Log Files would not display any chart info in Monitors or Dash information. The data was there as I could see it in Items Lists. ...

I took if for a run. At WOT the O2 is not cycling, ~969mv.
During 'normal' cycling it's low ~60 - 70mv. Lowest seen 31mv. So don't think have O2 ground issue.

I would love to try the New...

billygraves, thanks for you reply.
Both of the 2 new O2 sensors cycle hi/lo. The O2 to exhaust is clean connection as had to tap the hole after the bad original one came out hard (3 pound hammer...

Stared at the scan readings for hours looking for any correlations. Can't see any correlation, positive or negative, other than rpm 2000 +/- 500.
No O2 correlation that I can see, spark advance...

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I have not tried to measure that O2 ground with the motor running. The sensor ground is through the threads.
My pcm ground to back of engine, which I can't reach. Have tested by running a...

All the plugs were turning black.
I didn't record the fuel pressure, but I remember it was in spec and I think ~60psi. Leak down test passed.
No adjustment on the fuel regulator. 2 spider...

I don't know if 'stock' as I don't full history, but I assume stock. The previous owner said he had put in about $2500 in parts is all I know.
So, ~10% change might not be of concern. If my math...

After replacing the spyder fi, nut kit, and tuned VE tables because still too rich, my Sonoma surges at light throttle.
Found Service Bulletin 57-65-03A which recommend upgrading my old prom (BHRH)...

project is 1994 Sonoma 4.3L vin W. Was running rich, retuned and running much better, but still have surging. And other questions about large shift in VE table effects.

Hi, here to learn!