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From: Jeff Strickland on 14 Mar 2010 11:30

"Ray O" <rokigawa(a)NOSPAMtristarassociates.com> wrote in message
news:hnhqek$hpc$1(a)news.eternal-september.org...
>
> "Jeff Strickland" <crwlrjeff(a)yahoo.com> wrote in message
> news:hnh6se$p7$1(a)news.eternal-september.org...
>>I have my scan tool connected, and the O2 Sensor errors are not coming up,
>>but I am getting repeated unique codes for Fuel Control (P1188 and P1189)
>>that don't turn the MIL on. I also got an instance or two of P0170 and
>>P0173, Fuel Trim, B1 and B2, respectively.
>>
>> I also am getting pounded by P03nn series errors that indicate Misfire of
>> the plug position represented by nn. The test scenario is that the car is
>> parked my my garage with the engine running (garage door open, DUH!), but
>> not moving anywhere.
>>
>> I did drive the car 25-ish miles and had the P1188 and P1189 codes that
>> did not light the MIL, and that would go away on their own as I drove --
>> the scan tool repeats the scan every 30 seconds, and several times the
>> repeat scan would turn the codes off without me having done anything. I
>> got a couple of P0170 and P0173 events that turned the MIL on. I also got
>> random misfires that never hit all cylinders at the same time, but did
>> hit them all in varying combinations.
>>
>> If there was a misfire, then that would pump lots of gas into the exhaust
>> stream before the car reacted. If the misfire events were separated by a
>> few firings of good plugs, then could the resulting fuel levels be high
>> enough to trigger the Fuel Control (P1188 and P1189) codes and the Fuel
>> Trim codes also? Maybe all I need is a box full of spark plugs ... Also,
>> if the misfire event is singular and repeated after a proper firing
>> event, and spread across different plugs that also have singular misfire
>> events, would the result be lots of fuel in the exhaust that the O2
>> Sensors would report as Fuel Trim and maybe the O2 Sensor Malfunction
>> (P0130 and P0150)>
>>
>>
> OK, if you purchased the car used, and the maintenance history is unknown,
> then I'd start by replacing the spark plugs with OEM spark plugs and
> ignition wires. Multiple misfire events can cause the O2 sensors to
> detect a richer mixture than the fuel trim can control.
>

I just finished with the new plugs. No wires, I have coil-over-plugs. I hope
the coils aren't worn out. I have a '94 that has no problems with the same
configuration, and another '94 before that with 250K miles and no problems
with the coils.

I also pulled the MAF and cleaned it with a Q-tip and Carb Cleaner. It
didn't LOOK dirty -- no visible signs of discoloration or debris -- and the
Q-tip came up clean. I cleaned the MAF first, then replaced the plugs.

Still getting P0170 & P0173 codes for Fuel Trim, and P1188 and P1189 for the
Fuel Control (unique BMW codes).

I've been going on the idea that two O2 Sensors would not fail at the same
time, but maybe that is a flawed idea. Maybe one sensor went south a long
time ago and they ignored it, then the other one went. Then along came Jeff
to discover two bad sensors.

The diagnostic guide in my Bentley manual says that a misfire can come from
faulty O2 Sensors. there are also other causes that include the fuel pump,
the Evap System, and a few other things, but none of those other things are
throwing a code. The O2 Sensor is throwing codes and can contribute to a
misfire. I assume that a misfire can contribute to a faulty O2 Sensor
reading, but I missed that a faulty sensor downstream from the plugs can
contribute to a misfire. I'm not sure how that can be, but it's in my book.




> As far as the fuel injector cleaner goes, I do not recommend routinely
> putting stuff into the fuel tank as it can eventually damage the
> injectors, but Techron fuel injector cleaner is safe to use to correct a
> clogged injector as needed, i.e., when a possible clogged fuel injector
> condition exists.
>
> If your scan tool has the ability to freeze frame O2 sensor voltages, then
> you can see if they are detecting rich or lean conditions. A rich
> condition could be caused by an ignition misfire, and a lean condition
> could be caused by a clogged injector. If you had a multi-lead
> oscilloscope, you could see the relationship between O2 sensor voltages,
> ignition, and injector pulses.
> --
>

My Scan Tool apparently only freeze frames the Priority Code, which is
defined as the first code displayed. This is typically the P1189, which is a
unique BMW code, and the tool claims there is no freeze frame data for the
code. Sometimes the first code is for a misfire, P03nn, and there is no
freeze frame for those either.

I do not have an o-scope, but I do have several DVMs.







From: Jeff Strickland on 14 Mar 2010 12:09
MISFIRE CAUSES
My Bentley manual states the following causes for a misfire

Ignition Fault
Defective or wrong plugs; defective coil(s).

Mechanical Fault
Crankshaft pulse wheel loose or damaged; damaged piston(s), damaged valve(s)
or damaged camshaft(s); low oil pressure

CAT Fault
Excessive backpressure due to restricted CAT

Fuel Supply Fault
Contaminated gas; delivery trouble (clogged filter, defective pump); running
loss system fault <I do not know what that means>; leaking or blocked
injectors; pressure regulator fault; Evap System fault.

ECM Fault
Implausible signals;O2 Sensor fault, ECM faulty


I've replaced plugs. There are no fault codes for any of the other items
except the O2 Sensors. Some of those items will not throw a code, but some
will and have not.


From: Ray O on 14 Mar 2010 21:27

"Jeff Strickland" <crwlrjeff(a)yahoo.com> wrote in message
news:hnivfc$c6q$1(a)news.eternal-september.org...
>
> "Ray O" <rokigawa(a)NOSPAMtristarassociates.com> wrote in message
> news:hnhqek$hpc$1(a)news.eternal-september.org...
>>
>> "Jeff Strickland" <crwlrjeff(a)yahoo.com> wrote in message
>> news:hnh6se$p7$1(a)news.eternal-september.org...
>>>I have my scan tool connected, and the O2 Sensor errors are not coming
>>>up, but I am getting repeated unique codes for Fuel Control (P1188 and
>>>P1189) that don't turn the MIL on. I also got an instance or two of P0170
>>>and P0173, Fuel Trim, B1 and B2, respectively.
>>>
>>> I also am getting pounded by P03nn series errors that indicate Misfire
>>> of the plug position represented by nn. The test scenario is that the
>>> car is parked my my garage with the engine running (garage door open,
>>> DUH!), but not moving anywhere.
>>>
>>> I did drive the car 25-ish miles and had the P1188 and P1189 codes that
>>> did not light the MIL, and that would go away on their own as I drove --
>>> the scan tool repeats the scan every 30 seconds, and several times the
>>> repeat scan would turn the codes off without me having done anything. I
>>> got a couple of P0170 and P0173 events that turned the MIL on. I also
>>> got random misfires that never hit all cylinders at the same time, but
>>> did hit them all in varying combinations.
>>>
>>> If there was a misfire, then that would pump lots of gas into the
>>> exhaust stream before the car reacted. If the misfire events were
>>> separated by a few firings of good plugs, then could the resulting fuel
>>> levels be high enough to trigger the Fuel Control (P1188 and P1189)
>>> codes and the Fuel Trim codes also? Maybe all I need is a box full of
>>> spark plugs ... Also, if the misfire event is singular and repeated
>>> after a proper firing event, and spread across different plugs that also
>>> have singular misfire events, would the result be lots of fuel in the
>>> exhaust that the O2 Sensors would report as Fuel Trim and maybe the O2
>>> Sensor Malfunction (P0130 and P0150)>
>>>
>>>
>> OK, if you purchased the car used, and the maintenance history is
>> unknown, then I'd start by replacing the spark plugs with OEM spark plugs
>> and ignition wires. Multiple misfire events can cause the O2 sensors to
>> detect a richer mixture than the fuel trim can control.
>>
>
> I just finished with the new plugs. No wires, I have coil-over-plugs. I
> hope the coils aren't worn out. I have a '94 that has no problems with the
> same configuration, and another '94 before that with 250K miles and no
> problems with the coils.
>
> I also pulled the MAF and cleaned it with a Q-tip and Carb Cleaner. It
> didn't LOOK dirty -- no visible signs of discoloration or debris -- and
> the Q-tip came up clean. I cleaned the MAF first, then replaced the plugs.
>
> Still getting P0170 & P0173 codes for Fuel Trim, and P1188 and P1189 for
> the Fuel Control (unique BMW codes).
>
> I've been going on the idea that two O2 Sensors would not fail at the same
> time, but maybe that is a flawed idea. Maybe one sensor went south a long
> time ago and they ignored it, then the other one went. Then along came
> Jeff to discover two bad sensors.
>
> The diagnostic guide in my Bentley manual says that a misfire can come
> from faulty O2 Sensors. there are also other causes that include the fuel
> pump, the Evap System, and a few other things, but none of those other
> things are throwing a code. The O2 Sensor is throwing codes and can
> contribute to a misfire. I assume that a misfire can contribute to a
> faulty O2 Sensor reading, but I missed that a faulty sensor downstream
> from the plugs can contribute to a misfire. I'm not sure how that can be,
> but it's in my book.
>
>
>
>
>> As far as the fuel injector cleaner goes, I do not recommend routinely
>> putting stuff into the fuel tank as it can eventually damage the
>> injectors, but Techron fuel injector cleaner is safe to use to correct a
>> clogged injector as needed, i.e., when a possible clogged fuel injector
>> condition exists.
>>
>> If your scan tool has the ability to freeze frame O2 sensor voltages,
>> then you can see if they are detecting rich or lean conditions. A rich
>> condition could be caused by an ignition misfire, and a lean condition
>> could be caused by a clogged injector. If you had a multi-lead
>> oscilloscope, you could see the relationship between O2 sensor voltages,
>> ignition, and injector pulses.
>> --
>>
>
> My Scan Tool apparently only freeze frames the Priority Code, which is
> defined as the first code displayed. This is typically the P1189, which is
> a unique BMW code, and the tool claims there is no freeze frame data for
> the code. Sometimes the first code is for a misfire, P03nn, and there is
> no freeze frame for those either.
>
> I do not have an o-scope, but I do have several DVMs.
>

It just dawned on me that you are reporting bank 1 and bank 2 problems, but
I thought you said that you have an inline 6, which normally only has 1
bank.

If your scan tool does not display O2 sensor voltages, then hook up a volt
meter in parallel to the O2 sensor, rev the engine to 2,000 rpm, and check
for voltage fluctuation in the ranges that were in the link I gave before.
--

Ray O
(correct punctuation to reply)


From: Jeff Strickland on 15 Mar 2010 11:47

"Ray O" <rokigawa(a)NOSPAMtristarassociates.com> wrote in message
news:hnk3ts$7av$1(a)news.eternal-september.org...
>>
>
> It just dawned on me that you are reporting bank 1 and bank 2 problems,
> but I thought you said that you have an inline 6, which normally only has
> 1 bank.
>
> If your scan tool does not display O2 sensor voltages, then hook up a
> volt meter in parallel to the O2 sensor, rev the engine to 2,000 rpm, and
> check for voltage fluctuation in the ranges that were in the link I gave
> before.

Inline 6, but a split exhaust manifold, one takes the 3hree cylinders and
the one takes the other 3.







From: Ray O on 15 Mar 2010 19:28

"Jeff Strickland" <crwlrjeff(a)yahoo.com> wrote in message
news:hnlkql$cct$1(a)news.eternal-september.org...
>
> "Ray O" <rokigawa(a)NOSPAMtristarassociates.com> wrote in message
> news:hnk3ts$7av$1(a)news.eternal-september.org...
>>>
>>
>> It just dawned on me that you are reporting bank 1 and bank 2 problems,
>> but I thought you said that you have an inline 6, which normally only has
>> 1 bank.
>>
>> If your scan tool does not display O2 sensor voltages, then hook up a
>> volt meter in parallel to the O2 sensor, rev the engine to 2,000 rpm, and
>> check for voltage fluctuation in the ranges that were in the link I gave
>> before.
>
> Inline 6, but a split exhaust manifold, one takes the 3hree cylinders and
> the one takes the other 3.


Sorry, I had a brain fart - split exhaust manifolds are not uncommon on long
engines.
--

Ray O
(correct punctuation to reply)


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