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Map reading and fuel are way out of wack please help I'm getting 5mpg

Old 10-01-2012, 03:19 AM
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Default Map reading and fuel are way out of wack please help I'm getting 5mpg

The cars a 92 with an original mspnp with a map daddy and vtps. The car was running better than ever then all of a sudden my afr is between 9 and 10 or so. My map reading is fluctuation tremendously between 50 and 110 kpa at idle. This is all new, its never acted this way before.

I filled up the car today and after 90 miles of "tuning" and no change I'm out of gas. I need the car for work in the morning, but I just don't see it happening. If anyone can help I would appreciated it. At this point I'm willing to pay for a tune that just makes the car driveable, I don't care about max power.

Log and MSQ attached.

I do have a wideband, i re-calibrated the sensor, redownloaded the firmware and tried everything listed in the instructions and most help files I've found.

The cars running a t28 with rx7-460's
Attached Files
File Type: msl
2012-10-01_01.42.51.msl (493.8 KB, 131 views)
File Type: msq
2012-10-01_01.47.16.msq (41.1 KB, 143 views)
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Old 10-01-2012, 04:05 AM
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Looks like your map sensor is either not calibrated properly, or it is broken or the map line is pinched somewhere.
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Old 10-01-2012, 08:22 AM
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I've seen the 250BAR ones die often. They dont like sitting in winter months, they tend to get condensation in the line and kill the sensor.
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Old 10-01-2012, 08:28 AM
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Run a new line to eliminate possible kinks or leaks in the current one, just put it through the window for testing's sake. If that does fix it, replace the map sensor.
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Old 10-01-2012, 10:12 AM
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I will give the new line a shot. This is the 4bar map daddy sensor. BTW this weekend was the first time I've driven the car in the rain in a very long while. Thats when this issue started. Immediately after the car had been sitting in the rain for a while.
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Old 10-01-2012, 10:38 AM
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what do you have your baro settings at? Specifically the range in which youre allowing baro to work?
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Old 10-01-2012, 10:43 AM
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Sounds very similar to when moisture destroys the MAP sensors. Replacing the map line like I suggested probably won't do anything, but I'd do it anyways once you replace the actual sensor.
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Old 10-01-2012, 11:34 AM
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The baro correction is set between 26 and 96, but it was 26 to 110
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Old 10-01-2012, 11:38 AM
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it should be between like 80-110. that range will screw up things fast; when's the last time it was 26kPa out where you live?
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Old 10-01-2012, 12:02 PM
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ok, I will give that a shot as well. Yes, it was live at 26kPa for at least most of this year. Until this weekend it ran pretty good.

Originally Posted by Braineack
it should be between like 80-110. that range will screw up things fast; when's the last time it was 26kPa out where you live?
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Old 10-01-2012, 03:32 PM
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if it was 26kPa outside you would sufficate. That's less air than on top of Mt. Everest, BTW. Or 1/4 the oxygen available that I'm currently breathing.
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Old 10-01-2012, 03:57 PM
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I checked the settings when I went home today at lunch it is in fact 26-96 I changed it to 80-110. Two other points of reference, I had to change the alternator belt Saturday because the old belt failed. My friend said the car completely died, as in died because it drained the battery and the alternator wasn't running. I didn't really pay any attention to this since when she called we just got their and changed the belt. The car just restarted. I drove the car after it got home I didn't think this would have been related, but if the battery completely died while the car was driving could that have thrown a setting off.

The second thing I noticed that the kPa read as high as 150 while I was just sitting in the car with the ignition switched to on, but not running. Is that likely to be a dead sensor, or one that is mis-calibrated.

As far as I know I can't recalibrate the sensor with my version of the mspnp.

I can try running a new line when I get home from work this afternoon.

If none of this matters, then I will order a new sensor, or better yet send the ms to DIY just to make sure everything is ok.

BTW I also verified the map sensor is set to 400 under constants and 4 bar in under the project settings in Tuner Studio. Constant Baro Correction' to Extra MAP fitted to X7 is listed as well.
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Old 10-01-2012, 04:01 PM
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was the MSPNP purchased with the map-daddy installed? 150kPa is high, like I suggested, depending on your location, should be between 80-110kPa, where you should see 100kPa if around sea level.
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Old 10-01-2012, 04:15 PM
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No, the 400 sensor was added much later. I spoke with Ben about a reconfig of the sensor, he suggested I try the steps listed for my gen MegaSquirter. So I'm going to give the SNnS-e (029 and Newer) instructions a shot and see if maybe that helps. He said it should either be this, or a bad sensor (Config or Hardware). I'm a little concerned about going back to megatune to do this and then going back to Tuner Studio because of the error issue, but I don't think this particular issue is likely to get much worse.
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Old 10-01-2012, 05:13 PM
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I haven't played with MSI in so long that I can't remember if firmware must be changed for an upgraded baro sensor.

might have just been the engine constants and the project properties.
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Old 10-01-2012, 05:22 PM
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No, thats for the coolant/air temp tables only. MAP was only two flash variables, so no firmware flashing is necessary. AFR was dealt in volts, and then processed to AFR in MT/TS.
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Old 10-02-2012, 01:23 AM
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So I went through the setting and everything seemed to be in line in both Megatune and Tuner Studio, but the Map still listed 150 kPa. So I decided to disconnect the map line and leave it open, since as far as I know the reading should be basically the same connected or not if the engine is not running. Initially everything was the same. After 10 minutes or so I looked back at the MAP signal and it had dropped to around 114-120. I can see it fluctuate, and I'm not sure why thats happening, but it does change within that 6 point range. Considering condensation issues could leaving it open over night be a temporary solution?
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Old 10-02-2012, 08:11 AM
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i think le sensor is le dead. ive had to replace one on the map-daddy board, had similar symptoms.

what does the BARO gauge show as the atmospheric pressure?
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Old 10-02-2012, 11:05 AM
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The Baro gauge read 110.
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Old 10-02-2012, 11:13 AM
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yeah, your main sensor is fubared.
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