18.8@90mph?!
#1
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18.8@90mph?!
Yep, had some problems at the track tonight. When I try to launch, I bog real bad, and when i start to build boost, it's like i'm hitting fuel cut and the car bucks real bad and i hear that loud popping sound like fuel cut does. I could not accelerate at all through 1st and only about the latter half of 2nd. Once I was into third, the car would boogy quicker than the word of God, but not enough to make up for the dismal start. Anyone have any ideas why it would do this?
#3
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Bruce what the hell are you doing up at 4:46AM?!
Super, sounds like a fuel issue. Maybe a misfire from running lean?
I see you have a Vortech FMU, 1.8L injectors, 190HP @ 8psi, correct?
Is this the first time you've run the car through the gears hard?
Has it always done it?
Is your FMU hooked correctly?
What ratio disc is in it?
What do you idle at?
What's your vacuum reading?
O2 clamp installed?
Super, sounds like a fuel issue. Maybe a misfire from running lean?
I see you have a Vortech FMU, 1.8L injectors, 190HP @ 8psi, correct?
Is this the first time you've run the car through the gears hard?
Has it always done it?
Is your FMU hooked correctly?
What ratio disc is in it?
What do you idle at?
What's your vacuum reading?
O2 clamp installed?
#6
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Bruce:
Yeah, it's the stock AFM. However, it appears it has been disassembled at some point because the top cover has silicone around it.
Braineack:
This is not the first time, however I have noticed an odd phenomenon. The first time i run the car hard (enter boost suddenly) i get this problem. For instance, when i first get on the highway when leaving my subdivision. Every time after that first time, i can enter boost just fine without hesitation. The problem with the track is that you sit in the staging lanes so long, every run is my bad "first time".
To my knowledge the FMU is installed properly.
Don't remember the disk ratio right off hand. It's whatever Bruce is running, as he recommended it to me.
I idle at 1000 rpms (though it's been up to closer to 2000 since it got cold. it drops down to around 1000 if i blip the throttle a few times)
Vacuum levels at idle are nice and low.
Yes, i have Bruce's autotune installed.
samnavy:
oddly enough, the car is perfectly streetable as long as I take it easy in 1st gear and easily transition into boost. I can beat the heck out of it in 3rd and 4th though.
Yeah, it's the stock AFM. However, it appears it has been disassembled at some point because the top cover has silicone around it.
Braineack:
This is not the first time, however I have noticed an odd phenomenon. The first time i run the car hard (enter boost suddenly) i get this problem. For instance, when i first get on the highway when leaving my subdivision. Every time after that first time, i can enter boost just fine without hesitation. The problem with the track is that you sit in the staging lanes so long, every run is my bad "first time".
To my knowledge the FMU is installed properly.
Don't remember the disk ratio right off hand. It's whatever Bruce is running, as he recommended it to me.
I idle at 1000 rpms (though it's been up to closer to 2000 since it got cold. it drops down to around 1000 if i blip the throttle a few times)
Vacuum levels at idle are nice and low.
Yes, i have Bruce's autotune installed.
samnavy:
oddly enough, the car is perfectly streetable as long as I take it easy in 1st gear and easily transition into boost. I can beat the heck out of it in 3rd and 4th though.
#7
Your O2 sensor could be cooling down(or not yet heating up) so that you are getting a full rich shot of fuel as it references the O2 when the Autotune kicks in. If you have a 4 wire, the heater may be bad. (Sorry, I don't associate screen names with real names very well and didn't realize you had Autotune by your signature)
#10
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I'll look into these suggestions. The O2 sensor IS kinda old, and i've been meaning to replace it for a while now, since i went ahead and bought a 4-wire replacement. It's just a pain to get to where it is on the downpipe. Also, i'm getting like 15 mpg, and i regularly get a CEL when cruising at the same speed for very long, probably from the O2 sensor.
#12
The Autotune works off of the NB signal. If that signal is low due to the O2 not being hot enough, a bad connection, etc, the Emanage maps default to rich.
Further, if the Autotune is activated when cruising at high speeds because the pressure switch is set too low, you will throw a CEL and waste a lot of fuel. At 75-80MPH in a 1.6 the vacuum/pressure hugs -0- and can trip the switch at its' lowest setting.
Further, if the Autotune is activated when cruising at high speeds because the pressure switch is set too low, you will throw a CEL and waste a lot of fuel. At 75-80MPH in a 1.6 the vacuum/pressure hugs -0- and can trip the switch at its' lowest setting.
#14
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Haven't really noticed any issues when the CEL comes on other than the light itself. No hesitation, surging, or bucking. If I let off the gas ever so slightly, the CEL goes right back off and I can continue for another minute or two until the light comes back on.
#18
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I already have a 4-wire Bosch unit that I originally bought way back when i got the autotune.
I'm going to be following this info to set it up.
http://mymiata.paladinmicro.com/Miata4-WireO2.htm
If that doesn't alleviate the problem, i'll move on to the AFM, since the one i have is suspect (appearing to have been opened at some point).
I'm going to be following this info to set it up.
http://mymiata.paladinmicro.com/Miata4-WireO2.htm
If that doesn't alleviate the problem, i'll move on to the AFM, since the one i have is suspect (appearing to have been opened at some point).
#19
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Well, it's not the AFM. I swapped it with one from a wrecker. Doing the same thing.
Has anyone been able to get the O2 sensor off the downpipe without removing the downpipe? I can't see how to get a tool in there. Also, did any of you have any clearance issues with the steering shaft? The 1-wire sensor on there now comes awfully close to it, and i believe the 4-wire replacement may hit it.
Has anyone been able to get the O2 sensor off the downpipe without removing the downpipe? I can't see how to get a tool in there. Also, did any of you have any clearance issues with the steering shaft? The 1-wire sensor on there now comes awfully close to it, and i believe the 4-wire replacement may hit it.
#20
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HOLY MOTHER OF GOD
It was the O2 sensor. I found a way to get it off and there is just enough clearance.
Apparently, I need a clutch now though because it was sooooo not up to the task of boost in 1st or 2nd gear.
It was the O2 sensor. I found a way to get it off and there is just enough clearance.
Apparently, I need a clutch now though because it was sooooo not up to the task of boost in 1st or 2nd gear.
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