Ron-swede

Hi everyone. i'm a little lost to what results that is normal. can someone see if there is anything that looks out of range. the car runs fine but hesitates a little. and smell o lot off fuel, sorry for my bad English again i'm frozen swede

Injuneer

First - You need to provide info on your car. I can tell it's a 94/95 from the scan, and I can tell it's an auto trans from the scan. But you need a "signature" so everyone knows about your specific vehicle, so they can help you.

https://www.camaroz28.com/forums/lt1...nature-879835/

Second.... the log indicates your engine has only been running for 57 seconds. That explains why the PCM control is not in "closed loop", and possibly explains why the left (driver side) O2 sensor is "ready" (operating) and the right O2 (passenger side) sensor is "not ready" (not operating). The O2 sensors have to be hot to work, and your right O2 sensor is either still cold (there is a heater circuit in the sensor to help it heat up), or possibly defective.

Getting the PCM control into "closed loop" is important, because that utilizes the full capability of the PCM's A/F ratio control system, and that is how the PCM operates 99% of the time for "normal" driving. Additionally, a single frame of data is not very useful The PCM is updating almost 10 times per second. You have a single record representing 1/10th of a second. You will get more meaningful data by running a continuous data log, from cold start, through warmup, entering closed loop, driving on the street under various conditions.

All that said, I'll try to give you what I can learn from your single frame of data.

I can tell your car has an auto transmission, because of the target idle speed. And I can tell the transmission was in neutral. 650 RPM is the typical target idle speed for an auto trans, in neutral, with the engine fully warmed up (coolant temp indicates 207*F). Actual idle speed being 649 RPM is good.

I am not commenting on the A/C (air conditioning) data, because the data indicates it was not in use.

Idle air control (IAC) position is good. Anything in the range of 20-40 counts is OK at idle.

Intake air temperature (IAT) is very high at 133*F. That would seem to indcate the engine was running at idle, vehicle not moving, for an extended period of time, and the IAT sensor is heat soaked. If you drive the car, that temp will come down, closer to ambient air temp.

EGR 0% is normal - EGR is not used at idle.

Speed = 0 MPH indicates not moving.

Engine run time at 57 seconds is a limitation. To get the PCM control into closed loop, both O2 sensors have to be hot and working ("ready"), coolant temp must exceed 140*F (varies) and the engine run time "timer" must have timed out, typicaly 206 seconds.

Ignition volts are good

Barometric pressure looks good, assuming your elevation is close to sea level.

TPS volts are correct for a closed (0%) throttle position.

Mass air flow (MAF) is normal for a warm idle, at 650 RPM

Manifold absolute pressure (MAP) is good, indicating healthy engine intake manifold vacuum.

Spark advance is typical for an idling engine.

Knock retard is good at 0. Seldom see knock retard at idle.

Knock counts are OK. This is a data point we need to watch over time. The absolute number in the field is not important, it's how fast it is increasing.

EVAP is OK at 0. EVAP is not used at idle.

BLM cell 16 is normal for engine idling. There are 17 other cellls used when the engine is actually powering the car.

Bank 1 (driver side) O2 sensor reading indicates it has warmed up, and is (most likely) reading on the lean side, because the AIR pump is running (AIR pump relay = 1).

Bank 2 (passenger side) is close to 450 millivolts, and that is either a static reading of a faulty sensor, or the sensor is not warming up at the same rate as the other side. The high coolant temp indicates the engine was running and warmed up. Possibly you shut it off, restarted and that's why the run time = 57 seconds. If the engine was running immediately before you restarted it, may have a problem with the Bank 2 O2 sensor. This is where you need a continuous data log, since the O2 sensor readings change rapidly.

Bank 1 long term fuel trim (LTFT) at 130 is good. "Perfect" would be 128, but anything in the range of +/- 5% (122-134 is acceptable). The Bank 2 LTFT of 118 indicates a possible problem on the right bank of the engine, or with the right bank O2 sensor. The numbers you see in the LTFT boxes are "stored" long term fuel corrections, based on O2 feedback when the PCM was operating in closed loop. 118 would indicate the PCM was subtracting 7.8% of the fuel is would normally supply, to compensate for a perceived rich condition. Looking at a continuous data log, where the engine was operating over a broad range of engine load (MAP) and RPM would give insight into the other 17 cells, and possibly point in the direction of the cause of a problem.

Short term fuel trims (STFT) are typically locked at 128 when the PCM is in open loop.

Fuel injector base pulse width, with the right side (2.85 milliseconds) being lower than the left side (3.13 milliseconds) reflects the PCM using the 118 LTFT to reduce injector pulse width ("on" time), and lean out the perceived rich A/F condition on the right bank.

Fan relays are OK at 0 (0 indicates "off"/ 1 indicates "on"). First fan (1994) or both fans on low speed (1995) do not turn on until the coolant reaches 226*F. Second fan, or both on high speed occurs at 235*F. Your coolant temp is only 207*F.

Engine is in open loop (closed loop flag = 0), left O2 is "ready", right O2 is not. Fuel trim is at 0 (not enabled) because the PCM has not entered closed loop.

Fuel enable (VATS) at 1 indicates the "SECURITY" system has told the PCM it is OK to turn on the fuel system (pump and injectors).

Power enrichment is only used with the engine under load at (or near) wide open throttle (WOT).

Kickdown relates to the auto transmission with vehicle actually being driven.

Rest is related to PCM diagnostic codes, and none have been set = good.

Ron-swede

Thank you Fred that was very professional answer. i updated my profile sorry i missed it
the car was driven before the test as you thought. it been shut off and on a couple of times when i did the test. i will do a new test and hope its not in closed loop then. i will post a new picture then. Thanks

Injuneer

You don't want to post a "picture". You want to set Scan9495 up to record the data continuously from a cold start. Allow a couple minutes after startup for the engine Obama . Then drive normally for a few minutes making sure to vary RPM and throttle position. Make at least one WOT pull to near RPM redline.

Scan9495 will produce a .csv format file of the data, over the entire period the engine was running. I can review that file for you, reformatting as an Excel file to allow me to manipulate the data. I will also give you file of a 20+ page paper describing the data you are looking at, and what it all means.

Is there a specific problem with the engine that you are trying to solve? Or are you looking for confirmation that everything is working the way it is supposed to be working?

Ron-swede

ok will try to fix this tomorrow.it's 10 in the evening now in Sweden.Thanks again for taking the time. by the way the reason why i do this is that the car runs i little ruff and smell a lot of fuel, no leaks that i can see.

Ron-swede

Hello tried this today but can you describe how i set the program to record. all that i was able to to was to get a file saved that was excel file.
Ron

gaedbo

I don't know if this is the same problem I had, but here is some information that may be helpful to check on some things related to the Smell of Fuel.

https://www.camaroz28.com/forums/lt1...system-884666/

Chimera96

Ron

if you are able to monitor the passenger side 02 (bank 2) after car is warmed up and in closed loop note if its readings fluctuate quickly and does not sit basically static around 450. Injuneer is considerably more qualified than myself is analyzing log data

One thing to check is if you have a broken exhaust manifold bolt, generally the rear one. If so that will cause exhaust leak pre 02 and that 02 will read lean and PCM will command more fuel (may be why you smell it). This will also foul plugs on bank 2 and kill the 02

This may not be your problem but is something to check. Also confirm you have no exhaust leak pre CAT

Ron-swede

Thanks guys for this info i look in to it. Ron

Ron-swede

Now it should be right i hope injuneer. attached a file

Injuneer

I can take a look at it tomorrow.

Injuneer

Downloaded and opened the file. Formatting is a major problem. Extra columns compared to the standard report, then periodically through the log, the data suddenly jumps a column to the right, and adds another column. Then individual cells of data switch back and forth, left to right to left columns. Column labels appear to be incorrect with regard to units of measurement... for example O2 readings are labeled as "volts" but there is no decimal shown, meaning the readings are in millivolts. Could be a problem with the setup of "country".

I'm going to ask the author of Scan9495 to take a look at it to see if he can help.

I did take the time to trace the O2 sensor readings through the first five minutes of the log. Definitely a problem on the right/passenger/bank 2 side with the O2 sensor. It stays very close to 450 millivolts (mV) for a long time, then drifts slowly upwards to 500+ mV.. At the same time, the left/driver/bank 1 sensor has dropped as low as 50 mV, indicating the AIR pump is running. I can't clearly identify the column for the AIR pump relay, closed loop, or anything else that had data of either 1 or 0.

Eventually, I'm guessing, the AIR pump shuts off, and the left O2 sensor starts climbing, get up to 800+ mV. That's on the rich side. Then at 305 seconds the right side appears to start responding to the O2 sensor feed back, and the right O2 sensor starts to drop. Whatever it does, is does VERY slowly, and swings over a fairly narrow range, indicating a problem with the sensor.

I can't really follow any of the other columns without a huge amount of effort, so I can't see what the relationships are between sensor readings, PCM parameters, etc. We need to see if GaryDoug can't point you in the right direction regarding setup of the data logging.

GaryDoug

This is why the log file is badly formatted:
The program uses commas to separate the entries. The European pc setting uses the comma to delineate the decimal part of the number, where the US system uses a dot (period). So when the log file is generated in a European environment, you end up with too many commas and no decimal dot separators. Since the numbers sometimes have a decimal part but not at other times, you get a variable number of commas. This causes the columns to shift right or left, as well as being in the wrong place in the beginning.
The tip-off for this is in the photo of your screenshot. It shows commas in place of decimal points (dots)

There are two ways to temporarily fix this:

1. In the pc settings, change the decimal separator from a comma to a dot. This is what I recommend, so that other European settings can remain as is. In Windows 10, start the Control Panel, then click on Region. On the Formats tab, click on Additional settings; and then on the Numbers tab, change the Decimal symbol to a dot. Click on Apply and then on OK.


or:

2. Change the PC's country setting to US. This works fine, but you will probably see other changes that are not wanted. For Windows 10, start the Control Panel, then click on Region. On the Location tab, change the setting for Home location to United States. Click on Apply, and then on OK.

Ron-swede

Thank you both injuneer and Garydough for your help.
it seems its most likely a problem with the right 02 sensor as i understand.
i can try to do the changes in my pc just for the fun to see if it reads it correct.
Thanks again for the time

Injuneer

Thanks Gary. You've explained that before, but I couldn't remember the specifics.