Where is all my power?
#1
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Where is all my power?
I have had my megasquirt in my car for roughly 2 weeks now and for the most part the car runs great. I have been reading a lot and learning a ton but am still a noob with tuning and I need some people who know what they are doing to give me some input.
My main issue is that when I try to accelerate at anything more than a gradual pace I have a noticeably choked powercurve until about 6k rpms and then it takes off for the whole 1k rpms I have left. This feels a lot like the problem the stock ecu is known for having. I went out for a quick drive today for about 5-10 minutes and data-logged the entire thing.
I noticed a few things looking at the log that seemed weird. My MAT is reading a steady 70 degrees F at all times except for when I turn the car off and it jumps to 267. That seems odd that it would be so static so I assume it is not getting signal and I need to check the wires.
I also have the GM boost solenoid hooked up and it does not seem to be working either. I set the boost cut at 200 kpa and it doesn't get above 168. Currently my boost DC tables are set at 100 across the board. I am assuming I have a leak somewhere, probably a loose hose or coupler.
The last thing I want to address is the fact that I have not been able to do many red line pulls to tune fuel in the upper rpm range so I realize that the AFR goes really rich at 5k rpms and lean after 5k. What is confusing to me is that if you look at my fueling tables it is pulling a ton of fuel at 5k and still reading rich and then it has to add back a lot of fuel after 5k because it goes lean. I think something else is causing noise at 5k rpm and I fear that all the fuel it is pulling is making the engine run really lean even though the sensor is reading rich. The car does seem to bog down at 5k like it is running rich but I just don't understand why the fueling would go so wierd right there.
Any input for any of these problems would be helpful. My build thread is in my signature and I have attached the msq. I cannot attach the log for some reason. It keeps failing and I know it does not exceed the file size max.
My main issue is that when I try to accelerate at anything more than a gradual pace I have a noticeably choked powercurve until about 6k rpms and then it takes off for the whole 1k rpms I have left. This feels a lot like the problem the stock ecu is known for having. I went out for a quick drive today for about 5-10 minutes and data-logged the entire thing.
I noticed a few things looking at the log that seemed weird. My MAT is reading a steady 70 degrees F at all times except for when I turn the car off and it jumps to 267. That seems odd that it would be so static so I assume it is not getting signal and I need to check the wires.
I also have the GM boost solenoid hooked up and it does not seem to be working either. I set the boost cut at 200 kpa and it doesn't get above 168. Currently my boost DC tables are set at 100 across the board. I am assuming I have a leak somewhere, probably a loose hose or coupler.
The last thing I want to address is the fact that I have not been able to do many red line pulls to tune fuel in the upper rpm range so I realize that the AFR goes really rich at 5k rpms and lean after 5k. What is confusing to me is that if you look at my fueling tables it is pulling a ton of fuel at 5k and still reading rich and then it has to add back a lot of fuel after 5k because it goes lean. I think something else is causing noise at 5k rpm and I fear that all the fuel it is pulling is making the engine run really lean even though the sensor is reading rich. The car does seem to bog down at 5k like it is running rich but I just don't understand why the fueling would go so wierd right there.
Any input for any of these problems would be helpful. My build thread is in my signature and I have attached the msq. I cannot attach the log for some reason. It keeps failing and I know it does not exceed the file size max.
#2
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AIT is not hooked up correctly then, 70° is the default failsafe.
can you post the log?
was the trigger angle set using a timing light? or did Reverant say that value used is good to go? otherwise it looks like the fuel map still needs a bit of work and is going to be holding you back until it's tuned.
can you post the log?
was the trigger angle set using a timing light? or did Reverant say that value used is good to go? otherwise it looks like the fuel map still needs a bit of work and is going to be holding you back until it's tuned.
#3
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I keep trying to post the log but it keeps failing everytime. I cannot figure out why it won't work. The file is not too big.
I set base timing with a timing light.
The fuel map is definitely not perfect and I could understand if that is why I didn't have power above 4.5k rpm. The problem is I know that I am lacking response and torque all over and I have been autotuning up to 4.5k almost everyday on my way to work.
I floor it just feels like nothing is happening. Maybe my AE settings are off?
I set base timing with a timing light.
The fuel map is definitely not perfect and I could understand if that is why I didn't have power above 4.5k rpm. The problem is I know that I am lacking response and torque all over and I have been autotuning up to 4.5k almost everyday on my way to work.
I floor it just feels like nothing is happening. Maybe my AE settings are off?
#10
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Holy **** rev. I think that is it. I remember reading that on someone elses MSM MS install but I completely forgot about it and that is what causes these symptoms. I'll try that and report back.
#13
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This was definitely the problem. It fixed the choked problem, the boost problem, and the 5k bog prolem. The car now pulls like a train as soon as I touch the gas.
My fuel tables are all kinds of messed up though. They were incredibly lean because of all the air that was being blocked before. I autotuned them for about 10 minutes and then came home and richened up the top half of the map a lot by hand because it was too lean and I did not want det all over the place.
Thank you Rev for pointing me to the problem. I will be enjoying the car much much more now.
My fuel tables are all kinds of messed up though. They were incredibly lean because of all the air that was being blocked before. I autotuned them for about 10 minutes and then came home and richened up the top half of the map a lot by hand because it was too lean and I did not want det all over the place.
Thank you Rev for pointing me to the problem. I will be enjoying the car much much more now.
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