Running poorly/misfiring, code 33

[JeepsAndGuns]

Looking up the parts on rockauto, a 1985 camaro with the 305 tpi V8, and a 1985 corvette with a 350 tpi V8, they both show a large cap HEI distributor and they both look identical, but have different part numbers.

The pickup coils look identical but have different part numbers.
Camaro: https://www.rockauto.com/en/moreinfo...t=7176&jsn=595
Corvette: https://www.rockauto.com/en/moreinfo...t=7176&jsn=599

The coils (both large cap hei coils) look identical, but have different part numbers. The corvette has a red and yellow wire, while the camaro has a red and white.
Camaro: https://www.rockauto.com/en/moreinfo...t=7060&jsn=497
Corvette: https://www.rockauto.com/en/moreinfo...t=7060&jsn=558

The 7 pin module is the same part number.


Ok, doing a little more digging, I found reference to different ignition coils and that they need to be matched to the pickup coil. He says the coils function the same, but the polarity is reversed on the two, so the pickup and coil have to match.
https://www.chevelles.com/threads/he...rence.1089204/

I think I am just going to have to pick one (either camaro or corvette) and order both the pickup and the ignition coil, just so I know they are both matched, as right now it is a mix of junkyard parts.
The pickup I pulled out had the yellow connector and I am pretty sure the distributor came from a camaro. So I think I am going to pick that.
And yes, I do have the ground strap in place. I specifically remember putting it back in there.

[JeepsAndGuns]

Ok, so I ended up ordering the pickup coil and ignition coil for the camaro. I got the standard motor products pickup coil, and a ngk ignition coil.

The pickup and coil shipped separately, so I got the ignition coil first and swapped it out, but did not bother trying to start it. The pickup coil came a few days later and I managed to get it in yesterday. (I have a couple days off work).
Once I got the distributor reinstalled, I started it and it ran pretty crappy. I figured I did not have the distributor back in the exact same spot, even though I had marked it.
I ended up turning it a little while running and it smoothed out some. (had to retard it just a little). It was still running rich though.
Once it got up to operating temp, I shut it off, disconnected the bypass, crossed my fingers and tried it. Holy crap it started! I was finally able to set the base timing.
I reset the ecu and start it back up. It pretty much sounded normal. Seemed to throttle up and down ok. I drove it around my yard a couple laps with no issue, so I decided to go for a short trip 1/4 mile up the road to the intersection and back. It seemed to run normally, however it was still running rich. Generally around 12.5 on the wideband, but sometimes going as low as 11.5 and sometimes as high as 13.5. But it generally stated between 12.5-13.5
I think, maybe it just needs run and to "blow the soot out of it".
I drive it a couple miles away and back a couple times and got on it a few times. AFR never changed from the above.
It was lunch time by then, so I ate lunch at the house and hooked up tunerpro to it.
I start looking at the blm tables and everything is 128. I go for a short trip up the road and back, check the tables and everything is 128.
I was confused until my dumb-"you know what" looked at the main dash and saw the o2 sensor voltage was stuck at .450-something and was not moving or changing at all, and it showed it was in open loop.
No trouble codes were set though. I would have thought it would have set a code if it saw it was not reacting.

I checked the sensor and the plug and they looked fine. I am thinking maybe the o2 sensor has took a crap.
It is raining now so I can not check the wires and make sure power/ground are ok (it is a 3 wire sensor). But I think I am going to go ahead and order a new sensor.

The sensor is the 3 wire sensor listed for the 92-94 chevy C1500 5.7.
I have choices of NTK, delphi, denso, and a couple other off brands.
I have generally had good luck with ntk o2 sensors, and poor service life from bosch sensors. Any reason to pick a delphi or denso over the ntk?

[1project2many]

This is real progress! Nice!!

I use NTK, Delphi, or Denso sensors. I don't trust Delco branded products anymore and I seem to have consistently bad luck with Bosch.

Is there any chance the calibration is set for open loop only? It's free to check...

Also be sure to check for power / ground on the heater circuit. Cold sensors don't talk.

[JeepsAndGuns]

I have not changed anything in the tune, so unless it reprogrammed itself, it should still be set for closed loop. Plus it was working fine before the issues all started.
I'm thinking all the time I have spent trying to diagnose the issue and it running rich and dumping fuel into the exhaust, then setting for a few weeks between times running, has probably killed the sensor. I know raw fuel is not good for them.
I am going ahead and ordering a new sensor anyways, they are not very expensive, but will double check the power, ground, and sensor wire in the meantime.

I found a good price on the sensor on ebay for $14.99 with free shipping.
Looks like it fits several chevy and GM vehicles. I went ahead and ordered two, to have one as a spare.
https://www.ebay.com/itm/325453630014
Not sure if anyone else has a vehicle that uses that style, but figured if you did, here is a decent price on them.
NTK 21003 is the part number.

[1project2many]

I have not changed anything in the tune, so unless it reprogrammed itself, it should still be set for closed loop. Plus it was working fine before the issues all started.

It's happened to me! It's rare, but it's worth checking your prom to see if it matches your calibration.

Not sure if anyone else has a vehicle that uses that style, but figured if you did, here is a decent price on them.

That's a crazy low price. Hopefully it's the real deal.

[MO LS Noobie]

Has the new sensor arrived and have you installed it? Interested in how all of this plays out.

[mecanicus]

according to the second post of this thread:http://www.gearhead-efi.com/Fuel-Inj...6197427+wiring
i would check the ground connection of the lambda heater circuit.As well it should be possible to attach a four wire lambda probe by connecting the sensor curcuit ground to the ecu ground.I would prefere this.

[JeepsAndGuns]

Sorry for the late response. Weather has not been on my side. Seems like it has been raining here every weekend, the only time I have to work on it.

I checked for proper power and ground to the sensor and it was good. I checked the wire between it and the ecu and it was good.
I got the new sensor. While it the connector looked like the same weatherpack connector, it would not plug in. Turns out the little tabs around the terminals are slightly different. So no idea what the o2 sensor was from that I was running.
So I just simply depinned the old connector and used it on the new sensor. The pinout was the same.
Hooked it up and tested it.
It fired up and ran fine, but the AFR was still not adjusting. I hook up the computer and the value for the o2 sensor was still stuck at 451.
I pulled the memcal, read it, compared it and everything was right. I double checked the signal wire and it was still testing good.
In some frustration, I grabbed my spare ecu and plugged it up, and it now works! O2 sensor voltage was now swinging and the AFR was now adjusting.
I took it for a drive and it ran great, just like it always has. AFR was normal and it seemed like everything was back to normal.
So my guess was a bad pickup coil originally, then a mismatch of ignition coil and pickup coil when I tried swapping in the junkyard parts. Then the o2 sensor issue, who knows?

So I unbolt the old ecu from the dash and install the spare one. I park it for the day, thinking all was well again.

I go out the next day and me and the misses are going to go out for lunch. I decide to take the Jeep since it was finally fixed.
I get it in, it fires up just fine, but then sounds a little off. As soon as I start driving it, it is back to the original issue of missfiring like crazy, not on any 1 cylinder, and feeling like it is only hitting on half the cylinders.

I feel like I have just made a 5 month long complete circle right back to where I started. I just want to bang my head against the wall. I feel like I complete failure of a mechanic.