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Rouxzy's Avatar
 
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3.6 running rich

Does anyone know how the air/fuel mixture is adjusted on these? Is there an adustment or is it all done with the chip?
Tom

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Old 08-21-2006, 07:16 AM
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Asssuming it is stock 993, it is all done with the chip. Your O2 sensor(s) could be shot, though, which would make the system slow(er) to respond.

Also, there may be a limp home mode, if your system isn't getting all of the sensor inputs properly.

What are your AFRs?

Doug
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Last edited by DW SD; 08-21-2006 at 07:59 AM..
Old 08-21-2006, 07:22 AM
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If it's a 964 based 3.6 it has an air flow meter that can be adjusted.

Joe
Old 08-21-2006, 07:53 AM
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It is a 964 model. The O2 sensor was brand new when installed the beginning of last season.
Tom
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Old 08-21-2006, 09:32 AM
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How can you tell it's rich?
Old 08-21-2006, 08:11 PM
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Quote:
Originally posted by stlrj
If it's a 964 based 3.6 it has an air flow meter that can be adjusted.

Joe
The air flow meter has an air bypass screw that can be adjusted for idle mixure within certain boundries. This is to make sure the idle stabilizer does not max. out on either end. Other than that the mixture is defined by the O2-sensor during cruise and by a map during WOT. Nothing to adjust.

I too wonder how you came to the conclusion that it runs rich. Have you used a wideband O2 sensor such as the LM-1?

Cheers,
Ingo
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How about a NoBadDays DualChip for 964 or '95 993
Old 08-21-2006, 10:28 PM
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Hi Tom,
I just happen to have a wideband O2 sensor (LM-1) on loan from a friend this week and you owe me a ride in that bad boy...
Mixture is controlled by the computer but if the sensors aren't working correctly the motor can run rich.
Did Jerry wire up an OBD-II port on your motor?
-Chris
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Old 08-22-2006, 12:27 AM
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If it is running rich, could also be a bad Fuel Injector. Once in the Bronco, a bad FPR was allowing fuel to go into the FPR's vacuum side and then into the intake.
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Old 08-22-2006, 03:42 AM
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I'm assuming it is running rich because the exhaust pipe has a black soot covering the inside to the point where you can wipe it out with your fingers. Plus I've noticed it lately that the exhaust smell is quite strong.
Tom
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Old 08-22-2006, 05:44 AM
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Quote:
Originally posted by Rouxzy
I'm assuming it is running rich because the exhaust pipe has a black soot covering the inside to the point where you can wipe it out with your fingers. Plus I've noticed it lately that the exhaust smell is quite strong.
Tom
I notice exactly the same with my 3.6: Black soot in the tips and it smells (that's what people tell me who get stuck behind me for longer drives. But let me tell you - one track day and the exhaust looks shiny like on day one. It does burn those deposits off the tips just like that. The LM-1 is a very good idea. It will give you peace of mind.

Ingo

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1974 Targa 3.6, 2001 C4 (sold), 2019 GT3RS, 2000 ML430

I repair/rebuild Bosch CDI Boxes and Porsche Motronic DMEs
Porsche "Hammer" or Porsche PST2, PIWIS III - I can help!!
How about a NoBadDays DualChip for 964 or '95 993
Old 08-22-2006, 06:08 AM
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