Apparent problems with Autothority Mass Air Flow Sensor
06-19-2002, 03:32 PM
#1
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Apparent problems with Autothority Mass Air Flow Sensor
I posted this in the 911 forum but it occurred to me that someone in this area might provide advice on this issue:
<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=1&t=003468" target="_blank">http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=1&t=003468</a>
Basically, I have severe throttle hesitation as I accelerate, idle is fine. Car starts fine.
This problem began last fall, but was fixed when Autothority MAF was recalibrated. I re-installed and car ran great until a month ago, when it started hesitating again, a little at first, worsening over a two week period.
Pulled the unit off again, sent to Autothority and they sent a brand new unit. Re-installed and problem continues. I checked the cylinder head temp and it is the new one and seems to be in working order. Appreciate any additional thoughts insights before I replace this unit with the factory unit...I do like the slight performance gain.
Oh yes, the car has good compression on all cylinders (just had the valve adjustment done at Akers Porsche in Seattle). Akers doesn't want to monkey with the car and recommends putting the factory unit back on because they feel the aftermarket stuff creates most of these problems...
<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=1&t=003468" target="_blank">http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=1&t=003468</a>
Basically, I have severe throttle hesitation as I accelerate, idle is fine. Car starts fine.
This problem began last fall, but was fixed when Autothority MAF was recalibrated. I re-installed and car ran great until a month ago, when it started hesitating again, a little at first, worsening over a two week period.
Pulled the unit off again, sent to Autothority and they sent a brand new unit. Re-installed and problem continues. I checked the cylinder head temp and it is the new one and seems to be in working order. Appreciate any additional thoughts insights before I replace this unit with the factory unit...I do like the slight performance gain.
Oh yes, the car has good compression on all cylinders (just had the valve adjustment done at Akers Porsche in Seattle). Akers doesn't want to monkey with the car and recommends putting the factory unit back on because they feel the aftermarket stuff creates most of these problems...
06-20-2002, 08:41 AM
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Hi David!
You wouldn't happen to have an idea of your air/fuel ratios, would you?
Sounds to me that there could potentially be a fueling issue here. I'd bet you were going extremely lean when trying to accelerate, meaning that your car would bog horribly...
Perhaps a detailed description of the course of events too could help. Something like...
I start out at 2000 rpm, everything's fine, then I stomp on the gas. The car hesitates fir about 2 seconds and when I hit 3000 rpm it takes off as if nothing was wrong...
If you have the air/fuel ratios too - we might have a better chance or remotely diagnosing the issue!
HTH!
You wouldn't happen to have an idea of your air/fuel ratios, would you?
Sounds to me that there could potentially be a fueling issue here. I'd bet you were going extremely lean when trying to accelerate, meaning that your car would bog horribly...
Perhaps a detailed description of the course of events too could help. Something like...
I start out at 2000 rpm, everything's fine, then I stomp on the gas. The car hesitates fir about 2 seconds and when I hit 3000 rpm it takes off as if nothing was wrong...
If you have the air/fuel ratios too - we might have a better chance or remotely diagnosing the issue!
HTH!
06-21-2002, 02:07 PM
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Are you sure your car is running fine with the stock setup. You can get a used MAF for around 120 USD. I would try that first. It sounds like a fuel delivery problem. I don't think that autothority has done anything wrong, especially after sending you new stuff.
