O2 readings irratic

[buickturboman]

Should O2 readings be a consistent number? I was looking at the recommended readings Kent Chu linked me to on the Buick Site and it indicates O2 Voltage .45 +/- .10 .76 - .80 O2 Cross Counts 10-20 Note 1.
e
My Direct Scan showed no trouble codes but the O2 volt and x count readings are running up and down at a fast rate in a closed loop. Does this indicate a bad sensor?

 

[TurboDave]

The types of O2 sensors we use are narrow band, and as such will always be jumping around (A LOT) during normal cruise/light load conditions (closed loop), and the cross counts should be very active.
All normal conditions.

When you go to WOT the voltage will stop jumping around and settle in at some value based on your fueling. 700's 800's

 

[buickturboman]

I haven't looked at this stuff for about 2 years and forgot most of it all since the car was garaged but just idling the 02 volts were running up and down making it impossible to determine a read on it.

 

[buickturboman]

I may just buy a new one and see what happends with the O2 volt reading if it still runs up and down. As I recall, I was told not to get the heated O2 sensor. Does this sound right?

 

[Lee_Burough]

Take TurboDave's advice

You will find that you can take whatever Turbodave says to the bank....Save yourself some grief and leave it.

 

[buickturboman]

Sounds good. I was just confused how a reading was determined to follow under the circumstance that the readings fluctuate, especially when my o2 volt reading never stopped even when idling like running a marathon. I am experiencing a problem which which was not entirely a MAF problem if at all, hard to tell and I was hoping it may o2 related and now may have to look elsewhere.

 

[Lee_Burough]

Sounds good. I was just confused how a reading was determined to follow under the circumstance that the readings fluctuate, especially when my o2 volt reading never stopped even when idling like running a marathon. I am experiencing a problem which which was not entirely a MAF problem if at all, hard to tell and I was hoping it may o2 related and now may have to look elsewhere.

Two things:
1) What are the symptoms of the 'other' problem you mentioned?

2) The Computer in our Buicks monitors all the sensors, and changes parameters like fuel charge, timing and the like on the basis of the sensor readings. The closed loop condition uses 'feedback' from those dynamic sensor readings for emissions and fuel economy and performance. That feedback system is in normal operation when the o-2 sensor and cross counts are in contunual flux.

 

[buickturboman]

I replaced the EGR sensor since I broke off a tip to a vacuum line now a new MAF. My car seems to have a history of every now and then having the check engine light come on and the car then sputtering with a list of trouble codes. I normally drained down the computer then start the car and everything back to normal for awhile.
This time the car which has been in storage and driven around the block once every so often was doing the same thing but draining down thew computer didn't fix the problem. I swapped the computers and chip and still sputtering. I put the new MAF and swapped the computer again and better but still not right. I was looking at readings and saw the 02's running up and down with no reading I could obtain and assumed this could be a problem but now told otherwise.
I purchased the Kirban grounding system wondering if this would helpp years back but never had it installed. Hell, when I put the car away when it was running well it ran 12.1 at 1.9 60 foot times not hooking up with drag radials so she moves with a new turbo, 009 injectors 2 Red Armstrong chips, one is full race chip. I am a bit baffled. Yesterday it still didn;t run like it should hesitating a slight bit but with no trouble codes appearing. I may need to take coil pack readings and eventually take it to Buick. I may get around to trying a compression test. Oil os fine with no water mixed in. Any ideas?

 

[Lee_Burough]

What were the codes that came up?

Do you have fresh fuel in there now?

 

[buickturboman]

Yes, gas fresh.

Lately coding either 2 errors together -eprom error with computer chip or
a list of at least 5-8 different things I just dismiss since I assume it all can't be correct. Freaken crazy. IWhen it coded eprom and chip error, I changed chip alone to my race chip to see if that made any difference idling it only, ( I only have the one eprom chip so I had to leave that in) and it didn't change a thing on the trouble code. I noticed that I can then back out of the program and get back in it and it may not code or go the the different screen view after it codes only to find out is stopped coding. I ordered a new ribbon cable and this time with a shield to eliminate interference errors. It all gives me a headache trying to figure this one out.

 

[Lee_Burough]

You need to remove, inspect, straighten any misaligned contacts and reinstall the calpak. Then, try it again. I've posted some info from Turbolink that may help you sort things through.

You need to try a known good ECM, PROM, and Calpak (change only one thing at a time and then recheck it). You should start to gather known good spare parts like MAF, ECM, Ignition and coil for troubleshooting....Just for occasions like this (I realize you've done some of this already).

Do some creative searches using the search feature on this web site, and read what similar problems and solutions have been documented and saved here....There is bound to be something that will help you get on the right track.

Good Luck, I bet its something basic and relatively simple, you just have to find it.

CODE 51

Trouble Code 51 indicates that the ECM sensed a fault in the PROM.

When the PROM was initially created, a checksum number representing the total of all the cell values was also stored. The ECM uses this checksum as one way to determine if the contents of any cell has changed. A Code 51 causes the ECM to enter Back-Up mode which uses the CALPAK for default sensor values.

The conditions for setting this code are:

power has just been applied to the ECM, and
the calculated checksum does not match the stored checksum.
- or -
the engine was just started, and
either of two specific PROM locations do not contain the expected value. (One location should have 1's in the odd numbered bits and the other has 1's in the even numbered bit positions.)

Typical causes for this code include:

1) Incorrectly installed PROM module
2) Defective PROM module
3) Defective ECM

CODE 52

Trouble Code 52 indicates that the ECM sensed a fault with the CALPACK. The CALPACK is a plug-in module separate from the PROM, that contains preset calibrations used by the system during "limp home" (backup) mode. The ECM continuously checks for its presence while power is applied.

The conditions for setting this code are:

the ECM does not sense the CALPACK

Typical causes for this code include:

1) Incorrectly installed CALPACK module
2) Incorrect CALPACK module for this vehicle
3) Defective or incorrectly inserted PROM
4) Defective ECM

 

[buickturboman]

Great advice and I appreciate everyone's imput big time!!!

 

[onefastcar]

Just for giggles i would also look at the connectors to the ecm and to the ign module and make sure they are not corroded and or are properly seated just for piece of mind sakes.

 

[buickturboman]

When I get this fixed, my next thing it to get the razer alky kit. Would a DFI like Accel or FASST then eliminate the wire harness and stock computer, if you have the bucks to shell out for them?

 

[buickturboman]

My nephew had a '87 GN which did devolop a problem with a harness wire at the plug to the computer, now that you mentioned to check them. Removing a computer pulls on the entire harness and can certainly cause a wire to pull out enough not to make contact as it did for him. That did cross my mind, along with about a dozen other possibilities.
I will do try the elimination process as you suggested as well as checking the harness connections.Most things I have found over the years went back to something that was basic more then something complicated. My nephew that I mentioned was a gear head and got the GN after I told him how much I dug them and how I really wanted one. He built a Skylark and dumped tons into he car only to blow it up at the track. No car he owned was a fast as the GN he got. He didn't even know about these cars. Next thing I knew, he purchased one which made me jealous as hell. Guess this was a bit over 10 years ago now. I had to find a way to get one of my own and got my '86 with 62K on it, and it now has 88K. Mine got built up a bit because of him. He added a turbo then so did I, injectors and I followed suit and we both ran within a couple tenths of each other at Cecil County Drag Way with me always edging him out. Poor dummy had to sell his GN after he wasted his money doing stupid things. Damn glad I still having mine and can't wait to get this problem sorted out. Again, with all of the great info I have gotten from Lee and the others, I am sure I will get to the bottom this mystery soon. Thanks guys!