S/C LT1 Data Logs for Review
#1
S/C LT1 Data Logs for Review
Hi there!
Special thanks to GaryDoug for this great app and clear instructions to make it run and get data using a cable. I've build my own cable with no problems, using chinese FTDI 6-pin cable and 16-pin OBD-II connector with overall cost about $5. Also great thank you to Injuneer for help in this topic!
So, I've got data from my car. The goal is to understand what happening with my engine, cause it works bad, car goes, but not so fast as it must according to a factory specs.
Here is my logs (engine and transmission) http://www.mediafire.com/download/76...P3S2161187.zip
Thank you!!!
Special thanks to GaryDoug for this great app and clear instructions to make it run and get data using a cable. I've build my own cable with no problems, using chinese FTDI 6-pin cable and 16-pin OBD-II connector with overall cost about $5. Also great thank you to Injuneer for help in this topic!
So, I've got data from my car. The goal is to understand what happening with my engine, cause it works bad, car goes, but not so fast as it must according to a factory specs.
Here is my logs (engine and transmission) http://www.mediafire.com/download/76...P3S2161187.zip
Thank you!!!
Last edited by Novo; 09-18-2015 at 02:52 AM.
#2
Prominent Member
Join Date: Jul 2010
Location: Born on the Florida West Coast, now where can I retire?
Posts: 1,505
Re: Scan9495: Free OBD1 scan app for 94/95 LT1
There is a problem with the data, making it difficult to use. It appears the font set is incorrect for the U.S. I am not sure how to fix that. Can you load a western font set as the default? The tip-off is the date field that has some unreadable characters and some other columns may be wrong also. The date should look like this: This makes some entries a mismatch and so the lines are varying lengths, messing up the columns. Wish I was more of an expert and could help more with this issue. 18-Sep-15
It may have something to do with there being commas in the place of dots in the readings. The output routine uses the commas as separators for the data. If they are inside the numbers (like 12,2 instead of 12.2, becoming 12 and 2), that could split the data into separate columns (left part in one and right part in another). I will try to fix that eventually, but for now, see if you can change your setup to format numbers with dots.
It may have something to do with there being commas in the place of dots in the readings. The output routine uses the commas as separators for the data. If they are inside the numbers (like 12,2 instead of 12.2, becoming 12 and 2), that could split the data into separate columns (left part in one and right part in another). I will try to fix that eventually, but for now, see if you can change your setup to format numbers with dots.
#3
Re: Scan9495: Free OBD1 scan app for 94/95 LT1
Oh, I'm sorry! You're right!!! It's my fault. I always kept in mind, but forgot to change regional settings in my OS. So, I'll try to collect data tomorrow, in the morning.
Thenk you very much.
Thenk you very much.
#4
Re: Scan9495: Free OBD1 scan app for 94/95 LT1
In the meantime, I'll see if I can realign the column labels and make sense of the data. It gets a little confusing because of the way part of the data shifts over one column to the right at 8:21:57 and another part at 8:22:00,
What exactly do you mean by "runs bad"? Describe the specific problem and when it occurs.... startup, idle, cold engine, hot engine, part throttle, full throttle, etc.
Appears it may be a factory tune, since the target idle speed, fully warmed up, in gear, appears to be 550 RPM.
DTC 73 is a transmission problem:
Pressure Control Solenoid Current
Pressure control solenoid return amperage varies more than .06 amp from commanded amperage for one second.
Trans defaults to: *Harsh shifts, *Maximum line pressure
That's from Shoebox's code list:
http://shbox.com/1/Dtcs.htm
What exactly do you mean by "runs bad"? Describe the specific problem and when it occurs.... startup, idle, cold engine, hot engine, part throttle, full throttle, etc.
Appears it may be a factory tune, since the target idle speed, fully warmed up, in gear, appears to be 550 RPM.
DTC 73 is a transmission problem:
Pressure Control Solenoid Current
Pressure control solenoid return amperage varies more than .06 amp from commanded amperage for one second.
Trans defaults to: *Harsh shifts, *Maximum line pressure
That's from Shoebox's code list:
http://shbox.com/1/Dtcs.htm
#5
Re: Scan9495: Free OBD1 scan app for 94/95 LT1
Thank you for the answer.
So, I'll try to describe the problem. I know that maybe this text must be in separate topic, but I'll start here.
This brovblem is from the first day I bought this car. Must say that for cthe city car runs well - it has enough power and torque in any position of accelerator pedal to outrun most cars I want even if they resist. But if I want to measure 0 to 60 time - it is something about 8.3 seconds, that is too bad comparably to factory specs. It was all the time I use this car. One more fact is that when I press on the accelerate pedal, RPMs raise not so fast like I saw on another LT1 cars, for example another LT1 Camaro and even LT1 Impala, it looks like something prevents this process.
Also I must to say that my car is eqiped with Powerdyne BD-11A supercharger, Vortex Ignition Control and Paxta Map Fueler, but I don't know how all of this stuff works together. I use my car for everyday and when I go to work this is not a problem, but I know that my car is only LT1 supercharged Camaro in Ukraine and it must run very well.
I was at service station two months ago, where I changed oil to 5W30 and also checked compression in each of a barrel and it was good. But when spark plugs were moved to their places, the engine started to misfire and RPMs started to fall and raise on idling, but on the run engine is stable.
Maybe something is wrong with the fueling or ignition. Also I want to inspect spark plugs one more time (Denso Irridium).
One more fact. When I start the engine for example in the morning, I let it to warm up and for the third minutes of the idle it starts to shaking and RPMs become unstable.
Thats almost all... Sorry for my English.
So, I'll try to describe the problem. I know that maybe this text must be in separate topic, but I'll start here.
This brovblem is from the first day I bought this car. Must say that for cthe city car runs well - it has enough power and torque in any position of accelerator pedal to outrun most cars I want even if they resist. But if I want to measure 0 to 60 time - it is something about 8.3 seconds, that is too bad comparably to factory specs. It was all the time I use this car. One more fact is that when I press on the accelerate pedal, RPMs raise not so fast like I saw on another LT1 cars, for example another LT1 Camaro and even LT1 Impala, it looks like something prevents this process.
Also I must to say that my car is eqiped with Powerdyne BD-11A supercharger, Vortex Ignition Control and Paxta Map Fueler, but I don't know how all of this stuff works together. I use my car for everyday and when I go to work this is not a problem, but I know that my car is only LT1 supercharged Camaro in Ukraine and it must run very well.
I was at service station two months ago, where I changed oil to 5W30 and also checked compression in each of a barrel and it was good. But when spark plugs were moved to their places, the engine started to misfire and RPMs started to fall and raise on idling, but on the run engine is stable.
Maybe something is wrong with the fueling or ignition. Also I want to inspect spark plugs one more time (Denso Irridium).
One more fact. When I start the engine for example in the morning, I let it to warm up and for the third minutes of the idle it starts to shaking and RPMs become unstable.
Thats almost all... Sorry for my English.
Last edited by Novo; 09-19-2015 at 05:31 AM.
#6
Prominent Member
Join Date: Jul 2010
Location: Born on the Florida West Coast, now where can I retire?
Posts: 1,505
Re: Scan9495: Free OBD1 scan app for 94/95 LT1
You shouldn't apologize for your English. It is better than the "versions" that many of our members use ;-)
Last edited by GaryDoug; 09-19-2015 at 09:01 PM.
#7
Re: Scan9495: Free OBD1 scan app for 94/95 LT1
Thank you!
So, I've update my logs using US regional settings in OS. Here it is... http://www.mediafire.com/download/1s...S2161187_2.zip
This log files contain data from starting the engine, then warming up for about 2 or 3 minutes (it was made to show how the engine works and become unstable even on idling), then some unparking driving on very low speeds and accelerating the engine on "P" mode of transmission.It is noticeable that data from one of two lambda sensors doesn't change in any engine mode and RPMs. I don't know how it should be.
Yes, it often shifts harsh from first to second especially when the engine is warming and RPMs are slightly higher than when in idle. When on the run, it shifts from second to third normally but it's no problem to feel the shift.
So, I've update my logs using US regional settings in OS. Here it is... http://www.mediafire.com/download/1s...S2161187_2.zip
This log files contain data from starting the engine, then warming up for about 2 or 3 minutes (it was made to show how the engine works and become unstable even on idling), then some unparking driving on very low speeds and accelerating the engine on "P" mode of transmission.It is noticeable that data from one of two lambda sensors doesn't change in any engine mode and RPMs. I don't know how it should be.
Yes, it often shifts harsh from first to second especially when the engine is warming and RPMs are slightly higher than when in idle. When on the run, it shifts from second to third normally but it's no problem to feel the shift.
Last edited by Novo; 09-19-2015 at 12:38 PM.
#8
Re: Scan9495: Free OBD1 scan app for 94/95 LT1
Downloaded. Looks a lot easier to read.
Your Bank 2 (right side) O2 sensor is relatively static. When you get a reading near 450 mV, it usually indicates an open circuit. Could be the O2 sensor or the harness wires. Isn't completely static. Every once in a while it goes up and down, covering a range of 284 - 599 mV. Maybe a loose connection.
Is has not set the code for an open circuit - DTC 63 - and the data flag indicates the PCM is operating in closed loop.
One way to check the O2 sensors is to swap them side-to-side (left to right side, right to left side). If the problem follows the O2 sensor, it's an O2 sensor problem. If the problem stays on Bank 2 it's a wiring problem. Not easy to access and move the O2 sensors.
Some other things from a preliminary look at your data:
Battery voltage is slightly weak, dropping down to 12.7V. Would hope to see something closer to 13.0V.
MAP at idle, at the end of the log. appears to be slightly high, but that could be from the S/C.
For the idle cell, toward the end of the log, long term fuel trims (LTFT) indicate that Bank 1 (left) s being fueled correctly, with a 127 LTFT. Bank 2 (LTFT = 108) shows that the PCM is pulling about 15% of the expected fuel out of the injectors, to prevent what it sees as a rich condition. Not sure why this is happening, with the O2 sensor stuck near 450 milliVolts. You need to correct the static reading on the Bank 2 O2 sensor, and clear the PCM to see how that affects the Bank 2 LTFT. ... I don't know how the PaxtaMap fueler works. Is this the plate that goes behind the throttle body, and has three fuel injectors, or is it a boost referenced fuel pressure regulator? Or some sort of electronic controller?
The following appear to be normal - TPS volts, MAF flow,
No knock retard.
Your Bank 2 (right side) O2 sensor is relatively static. When you get a reading near 450 mV, it usually indicates an open circuit. Could be the O2 sensor or the harness wires. Isn't completely static. Every once in a while it goes up and down, covering a range of 284 - 599 mV. Maybe a loose connection.
Is has not set the code for an open circuit - DTC 63 - and the data flag indicates the PCM is operating in closed loop.
One way to check the O2 sensors is to swap them side-to-side (left to right side, right to left side). If the problem follows the O2 sensor, it's an O2 sensor problem. If the problem stays on Bank 2 it's a wiring problem. Not easy to access and move the O2 sensors.
Some other things from a preliminary look at your data:
Battery voltage is slightly weak, dropping down to 12.7V. Would hope to see something closer to 13.0V.
MAP at idle, at the end of the log. appears to be slightly high, but that could be from the S/C.
For the idle cell, toward the end of the log, long term fuel trims (LTFT) indicate that Bank 1 (left) s being fueled correctly, with a 127 LTFT. Bank 2 (LTFT = 108) shows that the PCM is pulling about 15% of the expected fuel out of the injectors, to prevent what it sees as a rich condition. Not sure why this is happening, with the O2 sensor stuck near 450 milliVolts. You need to correct the static reading on the Bank 2 O2 sensor, and clear the PCM to see how that affects the Bank 2 LTFT. ... I don't know how the PaxtaMap fueler works. Is this the plate that goes behind the throttle body, and has three fuel injectors, or is it a boost referenced fuel pressure regulator? Or some sort of electronic controller?
The following appear to be normal - TPS volts, MAF flow,
No knock retard.
#9
Re: Scan9495: Free OBD1 scan app for 94/95 LT1
One other thing I am going to have to do is move your posts to a new thread. This thread is for discussion of Gary's software, not individual tuning problems. I will move them all to a new thread and give it a title like Paxton S/C LT1 Data Logs.
Not sure how fast this is going to happen, since it isn't real easy to move things around, and if I'm not careful, the system may ask me for my Administrator dynamic password, and I'm not on a computer that allows me to access the password - it changes every thirty seconds.
Not sure how fast this is going to happen, since it isn't real easy to move things around, and if I'm not careful, the system may ask me for my Administrator dynamic password, and I'm not on a computer that allows me to access the password - it changes every thirty seconds.
#10
Re: Scan9495: Free OBD1 scan app for 94/95 LT1
Downloaded. Looks a lot easier to read.
Your Bank 2 (right side) O2 sensor is relatively static. When you get a reading near 450 mV, it usually indicates an open circuit. Could be the O2 sensor or the harness wires. Isn't completely static. Every once in a while it goes up and down, covering a range of 284 - 599 mV. Maybe a loose connection.
Your Bank 2 (right side) O2 sensor is relatively static. When you get a reading near 450 mV, it usually indicates an open circuit. Could be the O2 sensor or the harness wires. Isn't completely static. Every once in a while it goes up and down, covering a range of 284 - 599 mV. Maybe a loose connection.
I think it's better to do from under the car...
[QUOTE=Injuneer;6980700]or is it a boost referenced fuel pressure regulator? Or some sort of electronic controller?
Yes, it's too. http://www.mediafire.com/view/b7m939.../injectors.jpg
Also there are in the car...
http://www.mediafire.com/view/lj3uy0...on_control.jpg
http://www.mediafire.com/view/e22lwd...etard_knob.jpg
it is about that the engine has no detonations? Or that the knok retard deg is 0? It is good or bad?
Thank you very much! Fully agree - it is the good idea, cause to run the app and get the data from the car is not a problem for now. But I posted my answer here until it will be moved with all previous.
#11
Re: Scan9495: Free OBD1 scan app for 94/95 LT1
Not sure what the first picture shows. Obviously some sort of controller, but not sure what it controls. Look the top of the engine, between the throttle body and the intake manifold. The Carroll "Superfueler" added a 20mm thick plate, with three fuel injectors in this location.
Here are pictures I found online:
Bought a 96 LT1 about a month ago take a look - LS1TECH
FS: Paxton SN2000 Supercharger kit for LT1 - Corvette Forum
I understand the Paxton system was designed by Carroll Supercharging *now Blowerworks) here in New Jersey. But the second photo shows a picture of a relabeled MSD BTM (multiple spark discharge) box that improves the reliability of the spark under high boost, and allows ignition advance to be reduced under high boost. "Vortech" is another supplier of centrifugal superchargers, so your system appears to be constructed with parts from more than one source, although Carroll also worked with Vortech.
The third picture shows the control **** for the ignition box, allowing you to pull timing proportional to boost.
Right now, we are looking at basically the idle file, so the S/C and the controller are probably not coming into play yet. Let's focus on getting the O2 sensor problem sorted out, then attack the S/C. We have some very knowledgeable people on the "Forced Induction" forum, and that might be a good place to relocate the thread.
Here are pictures I found online:
Bought a 96 LT1 about a month ago take a look - LS1TECH
FS: Paxton SN2000 Supercharger kit for LT1 - Corvette Forum
I understand the Paxton system was designed by Carroll Supercharging *now Blowerworks) here in New Jersey. But the second photo shows a picture of a relabeled MSD BTM (multiple spark discharge) box that improves the reliability of the spark under high boost, and allows ignition advance to be reduced under high boost. "Vortech" is another supplier of centrifugal superchargers, so your system appears to be constructed with parts from more than one source, although Carroll also worked with Vortech.
The third picture shows the control **** for the ignition box, allowing you to pull timing proportional to boost.
Right now, we are looking at basically the idle file, so the S/C and the controller are probably not coming into play yet. Let's focus on getting the O2 sensor problem sorted out, then attack the S/C. We have some very knowledgeable people on the "Forced Induction" forum, and that might be a good place to relocate the thread.
#12
Re: Scan9495: Free OBD1 scan app for 94/95 LT1
The engine starts with the computer (PCM) in open loop. That means the mass air flow (MAF) sensor measures the air flow into the engine, and the PCM adds the theoretical amount of fuel required by that mass of air. The feedback from the O2 sensors is ignored, because 1) the sensors do not work correctly until they reach ~600*F, and 2) with stock programming, the AIR pump is forcing air into the exhaust system to burn the rich A/F mixture exhaust, to reduce emissions and help the O2 sensors heat up faster.
When three conditions are met (1 - O2 sensors are hot, 2 - coolant temperature exceeds ~120*F and 3 - 205 seconds have elapsed), the PCM switches to closed loop. Now it looks at the O2 sensors to see if the theoretical amount of fuel is correct, and uses the feedback from the O2 sensors to adjust the amount of fuel added to the measured mass of air. It does this first by raising or lowering the "short term fuel trims" (STFT) and if it finds that it is adding or subtracting fuel for a substantial period of time, is raises of lowers the "long term fuel trims" (LTFT) to make this adjustment more permanent.
The LTFT's are the main thing stored in the volatile memory of the PCM. Each bank of the engine is controlled independently. As a result, there are left bank (Bank 1) and right bank (Bank 2) LTFT's for each of the engine's 18 operating "cells". The cells are defined by a grid of MAP vs. RPM (cells 1-15), an idle cell (16), an open loop (or several other uses) load cell (18) and a deceleration cell (17).
You want the PCM in closed loop, so that the fuel usage is constantly adjusted to meet the specified A/F ratio of 14.7:1.
I think it's better to do from under the car...
It is strange, cause it's a new battery, that I bought in march. Try to charge it at home if it will help.
So it must be more higher when on the run, when the S/C will be on the boost?
it is about that the engine has no detonations? Or that the knok retard deg is 0? It is good or bad?
#13
Re: Scan9495: Free OBD1 scan app for 94/95 LT1
And one more fact... When my car was delivered in to Ukraine, it had all the stuff from Paxton kit and it was so until 2012 year (I learned that from sales ad photos in web archive), then somthing is happened and the Paxton supercharger was changed to Powerdyne one. Cause at the earlier photos there was the same Paxton air tube like on your second photo, but on the late photos and when the car was bought by me, there was the Powerdyne S/C with its own air tube with big "P" on it. So someone in Ukraine had change the S/C, maybe because of damage of that one.
For now I have different units from different kits:
1. Supercharger and air tube by Powerdyne.
2. Fuel map controller and injectors by Paxton (from SN2000 kit).
3. Ignition controll unit by Vortech.
4. Boost retard **** By MSD (found it at pictures from the web).
And when I bought my car I started to google those stuff and found that links that you provide (LS1Tech and Corvette Forum). For now I understand that not so many cars in the world was equipped stuff like this.
shows a picture of a relabeled MSD BTM (multiple spark discharge) box that improves the reliability of the spark under high boost, and allows ignition advance to be reduced under high boost. "Vortech" is another supplier of centrifugal superchargers, so your system appears to be constructed with parts from more than one source, although Carroll also worked with Vortech.
Back in the early-mid 80s Paxton went to Greg Carroll and had him design and engineer a kit for the L98 (and later the LT1 cars). Greg not only engineered the kits, but actually assembled them for Paxton. Greg sold his own version of the kits and in his words, "put a few 'goodies' into their kits versus the Paxton kits". Your kit was sold as a Paxton kit (it's carved into one of the large brackets), but I can guarantee it came from Greg.
Right now, we are looking at basically the idle file, so the S/C and the controller are probably not coming into play yet. Let's focus on getting the O2 sensor problem sorted out, then attack the S/C. We have some very knowledgeable people on the "Forced Induction" forum, and that might be a good place to relocate the thread.
1. O2 sensor problem to solve.
2. Spark plugs... I don't trust them from that moment when they was unscrewed and screwd back by mechanic at workshop. I have to check all of the eight gaps.
3. I want to see in to the S/C, maybe its bearings and belt are worn out, so the S/C is better in slowdown of the car then in speedup...
And thank you for complete information about how the PCM, MAF, O2 sensors work together, cause it was a wide knowledge gap for me.
Cool!
#14
Re: Scan9495: Free OBD1 scan app for 94/95 LT1
93-95 are U.S. Standard OBD-1. That only requires a pre-cat O2 sensor. GM decided to control each bank of the engine independently, so they have a pre-cat sensor on each bank of the engine.
After-cat sensors are required by the OBD-2 standard, and that was applicable starting in model year 1996. In 1996 LT1 GM used one cat for each bank of the engine, so they are required to have an after-cat sensor downstream of each cat. There was no after-cat sensor used from 93-95.
The purpose of the after-cat sensor is to verify the catalytic converter is installed, and operating within emission specifications. It does not control the engine to any significant extent.
I'll see if I can find a good photo of the stock exhaust manifolds. They are heavy cast iron. Tubular aftermarket headers will be thin gage steel tubing. If you post a link to a picture of the exhaust bolted to one of the heads, I can tell you if it is stock.
After-cat sensors are required by the OBD-2 standard, and that was applicable starting in model year 1996. In 1996 LT1 GM used one cat for each bank of the engine, so they are required to have an after-cat sensor downstream of each cat. There was no after-cat sensor used from 93-95.
The purpose of the after-cat sensor is to verify the catalytic converter is installed, and operating within emission specifications. It does not control the engine to any significant extent.
I'll see if I can find a good photo of the stock exhaust manifolds. They are heavy cast iron. Tubular aftermarket headers will be thin gage steel tubing. If you post a link to a picture of the exhaust bolted to one of the heads, I can tell you if it is stock.