Low Load/Low RPM Inconsistency?
02-13-2006, 07:24 AM
#1
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Low Load/Low RPM Inconsistency?
Hey Gents,
Driving to work this AM under 1/4 throttle the car seems to be inconsistent. Seems to buck a bit. Looking at the A/F gauge I see it go lean for a second when this happens. Going WOT the car pulls like mad like usual
My only thoughts are a bad fuel injector or Coil? Although a coil wouldnt cause it to go lean would it?
Driving to work this AM under 1/4 throttle the car seems to be inconsistent. Seems to buck a bit. Looking at the A/F gauge I see it go lean for a second when this happens. Going WOT the car pulls like mad like usual
My only thoughts are a bad fuel injector or Coil? Although a coil wouldnt cause it to go lean would it?
02-13-2006, 07:36 AM
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Bad Coil = unburnt fuel = rich at the O2 sensor. Might cause the ECU to dial fuel back on all ....
the other cylinders to compensate, therefore lean (but it would likely cycle on this)
Sounds more like an injector issue. Test them. Carefully.
Sounds more like an injector issue. Test them. Carefully.
02-13-2006, 07:48 AM
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Suppose can pull the injector connector one by one to see which one doesnt effect the car...
as bad as the others. Any other way to test it besides bench tests?
Car idles fine..so may be a hard test
Thx
cp<ul><li><a href="http://www.audifans.com/twiki/bin/view/Audi/FuelInjectorTest">http://www.audifans.com/twiki/bin/view/Audi/FuelInjectorTest</a</li></ul>
Car idles fine..so may be a hard test
Thx
cp<ul><li><a href="http://www.audifans.com/twiki/bin/view/Audi/FuelInjectorTest">http://www.audifans.com/twiki/bin/view/Audi/FuelInjectorTest</a</li></ul>
02-13-2006, 10:21 AM
#6
Even with my bad coils, (and lots of bucking in mid range) I got nothing but perfect A/F's
So if the ECU does dial back fueling for bad ignition it is correcting itself such that final A/F's still look good.
02-13-2006, 03:49 PM
#7
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Think I found the issue!!
Appears that velocity stack/guide of the airbox that directs air in to the MAF had broken and fallen INTO the airbox creating very variable and erratic airflow in to the MAF under low boost conditions. I had to remove it totally..and decided to put a screen on the MAF to hopefully get some directional guide to the air flow.
I havent driven it yet..so will let you guys know if it doesnt solve my issue..but I like this solution as is "cheap"
I havent driven it yet..so will let you guys know if it doesnt solve my issue..but I like this solution as is "cheap"
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02-13-2006, 06:22 PM
#8
Ha - I had a similar issue, but my car wouldn't even idle - I stole an flow-guide from a BMW MAF
<ul><li><a href="https://forums.audiworld.com/s4s6/msgs/86596.phtml">https://forums.audiworld.com/s4s6/msgs/86596.phtml</a</li></ul>
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