MS6 Total Loss of Power?
- Thread starter FX-MAN
- Start date
Two things are happening here.
1) There is a gradual loss of power caused by the PCM retarding timing as the coolant temps exceed 200F. At 200F there is a 10% timing retard, followed by additional timing retards for every 10F increase in coolant temp. So if your running around with 210-220F coolant temps, your down about 20-30 whp.
This type of power loss would be gradual instead of sudden, and would result in the car feeling "less peppy". Generally this would occur at the end of a drive, or after hammering on the car for a few minutes.
A service manager is graciously spending his time on a demo car trying to record data to help narrow down the sudden outburst of problems with power issues, and was out today "testing" the car to get data.
In 15F ambient air temps, the coolant reached 215F after multiple 10 mile drives at about 80% turbo usage. (Almost track driving conditions). Though this isn't the best of news, it still shouldn't be happening in daily driving conditions unless your really getting on the car.
Intake air temps are taken prior to the Turbo, which makes it impossible to gauge the relative effectiveness of the intercooling system. In 15F ambient, IAT temps were in the 50-60F's (when the 215F coolant temps were recorded). Actual intake temps are unknown due to the location of the IAT sensor. (Airbox prior to turbo).
2) Sudden power loss. Your driving along, go to pass, or drive with some force of acceleration, reach 4,000 rpm, and suddenly the wastegate opens, and boost goes to nada. This is a sudden and drastic change, and results in the loss of at least 100 bhp, if not more, past 4,000 rpm. It will feel as if you suddenly broke the car. This is independent of problem mentioned above, but may be related.
There is a variety of parameters that will cause the car to cut boost past 4k rpm if they are detected. The hunt is on for which one is causing the power loss issues which seem to be spreading among owners.
1) There is a gradual loss of power caused by the PCM retarding timing as the coolant temps exceed 200F. At 200F there is a 10% timing retard, followed by additional timing retards for every 10F increase in coolant temp. So if your running around with 210-220F coolant temps, your down about 20-30 whp.
This type of power loss would be gradual instead of sudden, and would result in the car feeling "less peppy". Generally this would occur at the end of a drive, or after hammering on the car for a few minutes.
A service manager is graciously spending his time on a demo car trying to record data to help narrow down the sudden outburst of problems with power issues, and was out today "testing" the car to get data.
In 15F ambient air temps, the coolant reached 215F after multiple 10 mile drives at about 80% turbo usage. (Almost track driving conditions). Though this isn't the best of news, it still shouldn't be happening in daily driving conditions unless your really getting on the car.
Intake air temps are taken prior to the Turbo, which makes it impossible to gauge the relative effectiveness of the intercooling system. In 15F ambient, IAT temps were in the 50-60F's (when the 215F coolant temps were recorded). Actual intake temps are unknown due to the location of the IAT sensor. (Airbox prior to turbo).
2) Sudden power loss. Your driving along, go to pass, or drive with some force of acceleration, reach 4,000 rpm, and suddenly the wastegate opens, and boost goes to nada. This is a sudden and drastic change, and results in the loss of at least 100 bhp, if not more, past 4,000 rpm. It will feel as if you suddenly broke the car. This is independent of problem mentioned above, but may be related.
There is a variety of parameters that will cause the car to cut boost past 4k rpm if they are detected. The hunt is on for which one is causing the power loss issues which seem to be spreading among owners.
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- 2003.5 Mazda Protege' MazdaSpeed
Finally someone with some good tech info.crossbow said:
Thanks man. Keep us posted.
My car is running fine now, and I have not been able to duplicate the issue. I was sure it would do it today after lunch, because it was basically the same conditions as saturday, but after lunch I had just as much power as I did on the way to lunch.
Then on my way home today, it was still awesome. No repeat problem.
I hope this one getts solved though. I would hate for it to start doing this one day while I am trying to pass on a dotted yellow.
And yeah, I have no way of knowing if it was a bad batch of gas.. from now on nothing but Chevron 94 is going into this car.
And.. I actually don't feel bad for the service guy who has to drive this thing around like he is on the track
lol.
My car is running fine now, and I have not been able to duplicate the issue. I was sure it would do it today after lunch, because it was basically the same conditions as saturday, but after lunch I had just as much power as I did on the way to lunch.
Then on my way home today, it was still awesome. No repeat problem.
I hope this one getts solved though. I would hate for it to start doing this one day while I am trying to pass on a dotted yellow.
And yeah, I have no way of knowing if it was a bad batch of gas.. from now on nothing but Chevron 94 is going into this car.
And.. I actually don't feel bad for the service guy who has to drive this thing around like he is on the track
lol.
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- Hemi Ram, 71 Plymth Scamp, 71 Plymth Duster 340, 69 Dart 340/4sp
crossbow said:
Just curious how you came up with the 10% timing loss thing. What do they run total timing?
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- Hemi Ram, 71 Plymth Scamp, 71 Plymth Duster 340, 69 Dart 340/4sp
FX-MAN said:
It still will not let me register in that other site. So I will correct them over here, feel free to tell them they are wrong.
There is no such thing as a high pressure fuel pump resistor pack. The high pressure pump is a mechanical pump driven off the camshaft controlled by a "spill control solenoid". This control solenoid is a duty cycle driven solenoid that gets it's signal from the pcm. The pcm monitiors the fuel pressure via fuel rail pressure sensor. There is no resistor pack, unless they are talking about the Injector driver module, in which isn't even a resistor pack.
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- Hemi Ram, 71 Plymth Scamp, 71 Plymth Duster 340, 69 Dart 340/4sp
Da 6 said:
I have all the manuals, Factory, and the speciality training manual.
black,
The voltage to the high pressure fuel pump is controlled by a resistor attached to a very large heatsink. It's the thing with the warning on it. Something like "Very hot don't touch".
Here's a snapshot so you know what I'm talking about.
The idea is...since this little bugger determines whether the high pressure pump gets battery voltage, or 9v. If something happens to it (like overheating or being damaged), the voltage to the high pressure fuel pump will be different then the pcm expects, which will effect the overall air/fuel ratio (if it breaks completely the car goes rich instead of lean) which would heavily effect performance.
I call it a resistor pack, just because it's in a giant freaking heatsink. Technically its just a resistor with a hsf.
Obviously its kinda of hard to figure out the exact problem when no cel is being thrown, and the problem tends to come, then go away. The fact nobody has a scanner isn't helping much.
One thing we do know, is that hsf gets unbelievably hot. Its possible that the resistance values are changing based on engine bay heat.
The voltage to the high pressure fuel pump is controlled by a resistor attached to a very large heatsink. It's the thing with the warning on it. Something like "Very hot don't touch".
Here's a snapshot so you know what I'm talking about.
The idea is...since this little bugger determines whether the high pressure pump gets battery voltage, or 9v. If something happens to it (like overheating or being damaged), the voltage to the high pressure fuel pump will be different then the pcm expects, which will effect the overall air/fuel ratio (if it breaks completely the car goes rich instead of lean) which would heavily effect performance.
I call it a resistor pack, just because it's in a giant freaking heatsink. Technically its just a resistor with a hsf.
Obviously its kinda of hard to figure out the exact problem when no cel is being thrown, and the problem tends to come, then go away. The fact nobody has a scanner isn't helping much.
One thing we do know, is that hsf gets unbelievably hot. Its possible that the resistance values are changing based on engine bay heat.
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- Hemi Ram, 71 Plymth Scamp, 71 Plymth Duster 340, 69 Dart 340/4sp
That makes sense only if the high pressure pump was an electric motor, which it is not. It is a mechanically driven pump. The only thing that controls the high pressure pump is the duty cycle driven solenoid, not voltage driven. The low pressure is electric pump and uses the system you are describing. Give me the page number where you got that off of, I'm pretty sure you are talking about the low pressure pump.
Edit- After looking at the manual, I am correct in my thinking. If you notice where the resistor section is in the manual, the high pressure pump is below it. Also look at the high pressure pump inspection section. It tells you to use the wds and look at the duty cycle number, not a voltage number.
Edit- After looking at the manual, I am correct in my thinking. If you notice where the resistor section is in the manual, the high pressure pump is below it. Also look at the high pressure pump inspection section. It tells you to use the wds and look at the duty cycle number, not a voltage number.
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crossbow said:black,
The voltage to the high pressure fuel pump is controlled by a resistor attached to a very large heatsink. It's the thing with the warning on it. Something like "Very hot don't touch".
Here's a snapshot so you know what I'm talking about.
The idea is...since this little bugger determines whether the high pressure pump gets battery voltage, or 9v. If something happens to it (like overheating or being damaged), the voltage to the high pressure fuel pump will be different then the pcm expects, which will effect the overall air/fuel ratio (if it breaks completely the car goes rich instead of lean) which would heavily effect performance.
I call it a resistor pack, just because it's in a giant freaking heatsink. Technically its just a resistor with a hsf.
Obviously its kinda of hard to figure out the exact problem when no cel is being thrown, and the problem tends to come, then go away. The fact nobody has a scanner isn't helping much.
One thing we do know, is that hsf gets unbelievably hot. Its possible that the resistance values are changing based on engine bay heat.
I have an OBD II scanner, but have not had the problem listed. If it arises I will hook it up and read the codes if any are present.
R
solid_snake
Member
- :
- 2006 Mazda Tribute S-V6
You need the WDS tester ($2,000(deadhorse)to go further inside the ECU systems
Blk,
I don't have the page numbers. I gave the booklet back to CP-E when I was done scanning in the pages.
http://forum.mazda6tech.com/viewtopic.php?t=4213
If the fuel pump resistor is for the standard low pressure fuel pump, why is it sitting in the engine bay? I see what your getting at though. If it is just for the low pressure fuel pump, it would still cause the same type of problems with a screwed up A/F ratio if the resistor was malfunctioning or damaged.
Rainman,
Can you please start recording coolant temps after drives? Would be appreciated if you have access to a can scanner.
I don't have the page numbers. I gave the booklet back to CP-E when I was done scanning in the pages.
http://forum.mazda6tech.com/viewtopic.php?t=4213
If the fuel pump resistor is for the standard low pressure fuel pump, why is it sitting in the engine bay? I see what your getting at though. If it is just for the low pressure fuel pump, it would still cause the same type of problems with a screwed up A/F ratio if the resistor was malfunctioning or damaged.
Rainman,
Can you please start recording coolant temps after drives? Would be appreciated if you have access to a can scanner.
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- Hemi Ram, 71 Plymth Scamp, 71 Plymth Duster 340, 69 Dart 340/4sp
All the relays for the pump are in the engine bay also. In that link you provided check out the current flow diagram. It shows the resistor in line to the low pressure pump. The resistor is there for when engine is at idle or when not much fuel is needed. If anything were to screw up it would the fuel pump speed control relay. As it is the component that directs the current through the resistor when the pcm tells it to.
The resistor isn't even used when engine speeds are above idle or extreme low cruising rpm.
Personally I don't see any of that failing. And I fail to understand why you would think it would cause a loss in power at higher engine speeds.
The resistor isn't even used when engine speeds are above idle or extreme low cruising rpm.
Personally I don't see any of that failing. And I fail to understand why you would think it would cause a loss in power at higher engine speeds.
Just grasping at straws. The # of owners effecting is growing rapidly and I'm working with a QMD dealer to try and replicate the power loss issue. He suggested the resistor, so we started looking into it, and the relays.
At first we thought it was performing the opposite function of what its actually doing. ie only being used under demand situations, not idle/low rpm. In that condition it could have been the culprit, if it was malfunctioning, or engine bay heat was putting it out of its heat range, changing its resistance values.
At first we thought it was performing the opposite function of what its actually doing. ie only being used under demand situations, not idle/low rpm. In that condition it could have been the culprit, if it was malfunctioning, or engine bay heat was putting it out of its heat range, changing its resistance values.
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- Hemi Ram, 71 Plymth Scamp, 71 Plymth Duster 340, 69 Dart 340/4sp
All I have read about always complain of a loss above 4k. Then one or two people say, "oh yeah, mine felt like it loss 20-30whp today". wtf.
What does that mean? I don't care if you get your timing backed off 10%, 5-6 degrees of timing is not going to make you lose 30hp. I personally feel by reading the descriptions that they had "the octane problem" and nothing else. But hey, what do I know.
What does that mean? I don't care if you get your timing backed off 10%, 5-6 degrees of timing is not going to make you lose 30hp. I personally feel by reading the descriptions that they had "the octane problem" and nothing else. But hey, what do I know.
Ya but all these people are now having the same complaints with 94 octane in the vehicles.
Btw on the standard 6s MTX, the inital timing retard past 200F provides a 10 whp loss the second it occurs.
We actually have a dyno chart showing the retard occur. I'd imagine a 20% retard might cause upwards of a 15-20 whp loss in feel.
http://forum.mazda6tech.com/viewtopic.php?t=2862&start=0
Blue line is the dyno run where the engine pulled timing the second coolant bypassed 200F. Racing beat also verified this with the 8 on their engine dyno. All the pcm's seem to respond similarily. There are additional timing retards as the temps climb.
I'd gander if you were really getting on the MPS 6, and your coolant hit 215-220F, on a decently warm day, combined with intercooler heatsoak, you'd probably be down a good 30-40 whp over a cool car that wasn't heatsoaked, or undergoing the above.
Btw on the standard 6s MTX, the inital timing retard past 200F provides a 10 whp loss the second it occurs.
We actually have a dyno chart showing the retard occur. I'd imagine a 20% retard might cause upwards of a 15-20 whp loss in feel.
http://forum.mazda6tech.com/viewtopic.php?t=2862&start=0
Blue line is the dyno run where the engine pulled timing the second coolant bypassed 200F. Racing beat also verified this with the 8 on their engine dyno. All the pcm's seem to respond similarily. There are additional timing retards as the temps climb.
I'd gander if you were really getting on the MPS 6, and your coolant hit 215-220F, on a decently warm day, combined with intercooler heatsoak, you'd probably be down a good 30-40 whp over a cool car that wasn't heatsoaked, or undergoing the above.
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