1987 454 TBI stalls at idle after a short time

[beady]

I would recommend going back to the voltage/ground check sheet and testing all the grounds.
Here's the checklist in an Excel sheet

Bill, I took all the voltage and ground readings, will post those from my phone in a minute, but I'm posting the winALDL log I took this morning while the truck warmed up and I took readings. It is/was mid-70's outside and the truck was stone cold, not started for days. I think I started the datalog before I startred the truck, and let it run the entire time. After a long while it entered closed loop as seen by O2 readings on winALDL and also by my DVM metering the O2 sensor pin. It seems after it entered closed loop the idle started surging, quite severely, and never stopped. It only filled in one cell of the O2 table, and a couple of the INT and BLM cells.

Mike

 

[beady]

I would recommend going back to the voltage/ground check sheet and testing all the grounds.
Here's the checklist in an Excel sheet

Bill, here are the voltage/ohm readings. The key on, engine off readings were taken cold.

 

[beady]

You must be registered for see images attach

 

[beady]

Video of truck surging at idle in closed loop:

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[beady]

Oh yeah, the O2 sensor ground (pin D6?), was NOT present previously. All the results above, and the surging in closed loop are WITH the ground present. I grounded D6 with a jumper cable. O2 reads now, but o2, blm, and int tables barely register.

 

[Bill USN-1]

OK, I'll need to transfer all the data into the sheet.
But, we need to go over the settings to do a data drive.

1. disconnect battery to clear all errors.
2. in winaldl-click data logger
uncheck raw box and check the other 3.
3. start engine, click start on logger.
4. select the BLM tab, at the bottom right, toggle to the Wide Avg.
5. once in closed loop the highlighted box will start filling with numbers.
6. drive until table is full from idle to 3200.
7. at end of drive, select save table at the bottom center of BLM page.
8. on data log box, select stop.
post or send me both files.
You should do this every time you log.

BLM is data that represents the correction to the fuel table based on the O2 feedback.
The cell goes from 0-256.
128 represents 14.7/stoick
BUT, if you see 128 in the BLM table, that normally means the fueling or the O2 feedback is so far off that the ECM is no longer using the feedback and is now in a commanded 128 mode. This is used to protect the engine.
BLM is sometimes referred to long term fuel trim.

INT is referred to short term fuel trim.
You really don't care about INT other than if the fuel table is correct, the BLM will be within 10% of 128 and the INT should be right near 128.

Your BLM's are way low indicating the fueling is way rich an the ECM is pulling fuel/reducing the time the injector is firing, to lean it out.
OR
The O2 is feeding bad info to the ECM and it is making corrections based on the bad feed back.
My thought is the latter.
The rolling idle speed indicates the engine is lean but the O2 is showing pig rich.
So the ECM keeps trying to remove more fuel.
If you are really that rich, you should be rolling black out the tail pipe.

If your engine is stock and the injectors and fuel pressure is stock, then the engine should run fine all day without an O2 connected and the O2 should still show about .455 in winaldl.
It will remain in open loop and drive just fine like with a carb.

If you're still running a heated O2, I would disconnect and make sure you only use the 1 wire from the ECM, D7
Run a standard 1 wire O2.
Do a logging run with the 1 wire O2.
Then disconnect the O2 and drive again.
Go thru the logging instructions each time.
Disconnecting the battery will clear old errors and clear the fuel trim memory in the ECM.
Your log had an O2 error at start up.
error
13 Oxygen sensor output remained at .35-.55 volts for more than one minute after warm up. Possible open circuit