Odd that the system seems to fail near the ideal value. Usually with the electrical instrumentation I work with things fail full scale or negative.
HawkRod Tour 2025 - (North East Region of USA)
- Thread starter HawkRod
- Start date
Agree. For example 4-20mA signals. If they fail to zero mA, you KNOW it has failed.
But I guess I am still not 100% sure what, if anything, has failed. If I have two O2 sensors that are calibrated for different readings, then they could both be stuck at 14.6. I thought I had the correct replacement O2 sensors, but I don't know. The only way to test this is to get a FAST O2 sensor and check with that. It would either fix the problem and prove that I have the wrong sensors, OR it would confirm that something else is messed up. At this point, there is no way to get a FAST O2 sensor before we leave for the tour.
I have to see if I can figure out how to test the O2 sensor pin connections leading to the computer to give me better ideas of what is wrong.
If they are compatible with a daily driver you can check them with a good analyzer.
My guess is it's the ECU.
Does the fast give a afr if you key it on and just wait for it to heat up? (No crank or start)
Should be dead lean.
I'd think it must show AFR when the key is on the the car is not running. I've had it for so many years, but really never look at it when the car is off.
I'll test it tomorrow morning to see what it does.
I got some interesting results today when I tested my O2 sensors.
I started with O2 #1. I removed it from my header and turned the system on. It read 14.5, but after a few seconds, it moved to 15.9 and stayed there. Then I wrapped it in a rag soaked with carb cleaner and it read 12.0. So it moved and reacted, but did not do so as much as I would expect with a wideband O2 sensor (I believe more like between like 10 to 20).
I then put in O2 #2 and performed the same test. It stayed at 14.5 the whole time and didn't move. Eventually, I saw it move to 14.3 with the carb cleaner soaked rag, but essentially no movement. Aha! So O2 #2 is either bad or wrong application I thought.
So I put O2 #1 back in and repeated my test. I wanted to see the numbers move again. This time it stayed at 14.5.
What?
So at this point I suspect either wiring or contacts. It could also be a bad ECU. I have to figure out how to test each wire feeding the O2 sensor. I believe they are heated with a 5 volt pair of wires, but I need to figure out which those are. But first, I will check the connection itself and be sure all the connectors look like they are physically connecting properly.
I started with O2 #1. I removed it from my header and turned the system on. It read 14.5, but after a few seconds, it moved to 15.9 and stayed there. Then I wrapped it in a rag soaked with carb cleaner and it read 12.0. So it moved and reacted, but did not do so as much as I would expect with a wideband O2 sensor (I believe more like between like 10 to 20).
I then put in O2 #2 and performed the same test. It stayed at 14.5 the whole time and didn't move. Eventually, I saw it move to 14.3 with the carb cleaner soaked rag, but essentially no movement. Aha! So O2 #2 is either bad or wrong application I thought.
So I put O2 #1 back in and repeated my test. I wanted to see the numbers move again. This time it stayed at 14.5.
What?
So at this point I suspect either wiring or contacts. It could also be a bad ECU. I have to figure out how to test each wire feeding the O2 sensor. I believe they are heated with a 5 volt pair of wires, but I need to figure out which those are. But first, I will check the connection itself and be sure all the connectors look like they are physically connecting properly.
Ahh, the simple things in life...
I checked my connections. In looking at the connector that the O2 sensor plugs in to, two connectors looked like they were a bit receded back into the plug. It wasn't super obvious, but they looked funny where I was now looking at them critically. So I went through and made sure all connectors were well seated in the plug.
The picture below is after I pushed them back into the plug, but i believe the circled ones were not making good contact. This meant there was no error because the computer saw a working sensor, but the sensor wasn't reading it correctly.
Once I pushed them back, I was able to get 15.9 to 10.0 AFR by letting the O2 sensor hang and then wrapping a carb cleaner rag around the it. Below is a picture of my computer showing lean.
I started the car and suddenly it is idling and behaving like it should. My issue might be fixed!
I will let the car cool, and then I will re-install my steering column, button up other stuff and go through the tuning of my system again to make sure all parameters are set as they should be. Then I will test drive it and report back.
We might be back in business!!!
I checked my connections. In looking at the connector that the O2 sensor plugs in to, two connectors looked like they were a bit receded back into the plug. It wasn't super obvious, but they looked funny where I was now looking at them critically. So I went through and made sure all connectors were well seated in the plug.
The picture below is after I pushed them back into the plug, but i believe the circled ones were not making good contact. This meant there was no error because the computer saw a working sensor, but the sensor wasn't reading it correctly.
Once I pushed them back, I was able to get 15.9 to 10.0 AFR by letting the O2 sensor hang and then wrapping a carb cleaner rag around the it. Below is a picture of my computer showing lean.
I started the car and suddenly it is idling and behaving like it should. My issue might be fixed!
I will let the car cool, and then I will re-install my steering column, button up other stuff and go through the tuning of my system again to make sure all parameters are set as they should be. Then I will test drive it and report back.
We might be back in business!!!
- Local time
- 1:27 PM
- Joined
- Jan 16, 2011
- Messages
- 76,284
- Reaction score
- 120,110
- Location
- NorCal Sierras
Gotta love an easy fix, hard to find, good catch there too, but not costly or hard to fixAhh, the simple things in life...
I checked my connections. In looking at the connector that the O2 sensor plugs in to, two connectors looked like they were a bit receded back into the plug. It wasn't super obvious, but they looked funny where I was now looking at them critically. So I went through and made sure all connectors were well seated in the plug.
The picture below is after I pushed them back into the plug, but i believe the circled ones were not making good contact. This meant there was no error because the computer saw a working sensor, but the sensor wasn't reading it correctly.
View attachment 1856566
Once I pushed them back, I was able to get 15.9 to 10.0 AFR by letting the O2 sensor hang and then wrapping a carb cleaner rag around the it. Below is a picture of my computer showing lean.
View attachment 1856565
I started the car and suddenly it is idling and behaving like it should. My issue might be fixed!
I will let the car cool, and then I will re-install my steering column, button up other stuff and go through the tuning of my system again to make sure all parameters are set as they should be. Then I will test drive it and report back.
We might be back in business!!!
good luck
I took it out for a drive: It's back driving as it did before, and should be ready for tour!
Just don't go crazy on the celebratory burnout.
- Local time
- 4:27 PM
- Joined
- Jul 17, 2008
- Messages
- 24,634
- Reaction score
- 74,074
- Location
- South Jersey USA
That is also my luck.at least you got a filter installed
AND new fuel injectors!at least you got a filter installed
- Local time
- 4:27 PM
- Joined
- Jul 17, 2008
- Messages
- 24,634
- Reaction score
- 74,074
- Location
- South Jersey USA
Hey you guys will end up close to my neck of the woods.. Just a thought on where you guys can eat. There is this place which has outdoor seating, good food and right on a creek…It’s about 20 minutes away from the Auto Mall. Safe travels to all.
The Inn at St Peter's Village
Google Search
Well, the 'ol girl as ready as she'll be for the trip. I didn't get the A/C valve installed so the A/C is still down, but everything else checks out OK.
Heck, I didn't even wash the winter dust, dirt (and even some rain) off of the car since I'll almost certainly be driving in the rain tomorrow and/or Friday.
Tomorrow is kick off at Watkins Glen!
Heck, I didn't even wash the winter dust, dirt (and even some rain) off of the car since I'll almost certainly be driving in the rain tomorrow and/or Friday.
Tomorrow is kick off at Watkins Glen!
Have fun guys!
Thanks I will try but my Mondays & Tuesdays are long days even worse now with the last 3-4 weeks of rain.... Let me know a time of when you are thinking of getting there or if you guys choose another place.Sounds like a great suggestion - thanks!
Join us if you'd like!
Skytrooper
1SG (Ret.)
See you all there later today. Safe travels all !
Similar threads
