What nut are you talking about here?
AFC idle issue
- Thread starter Wingman21
- Start date
What nut are you talking about here?
SpeedAdiction20
Member
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- 2003 MAZDASPEED Protege
^^ ya id like to know too, im pretty sure ive seen it before, but didn't know what it was, and can't remember exactly lol
Bump for my question
SpeedAdiction20
Member
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- 2003 MAZDASPEED Protege
oh well i think i know what nut he is talking about now, if it is the big metal nut that screws into the right side of the exhaust mani, with the metal pipping than that would make sense..
Metallic36
Member
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- 2003 Mazda6 3.0L Speed Yellow
I'd be curious to find out too.. my car is idling at around 17. I recently replaced the EGR, so I'd like to find out what screw to check. I have the Winter FMIC map installed.
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- 2002 BJFW, 2007 BK3P, 1979 SA22C, 2005 BK3P
yes that is what tony was talking about
exhaust leaks, even minor ones, closer to the primary o2 sensor will cause the car to run lean at idle, guaranteed. i am sure it has been discussed to death, but how one wires the power and ground for the AFC can affect things like this as well.
I will check that for sure... when it gets a bit warmer here! Its freaking cold today lol! I will also double check my power/ground wires, but I think that the ground one could be more of a problem if any.
So the screw is located on the right side if the exhaust manifold? And by screw I guess that you mean some kind of but that tighten up pipe join with the manifold?
Thanks
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- 2002 BJFW, 2007 BK3P, 1979 SA22C, 2005 BK3P
the EGR tube threads onto a fitting which looks, from first glance, like it is part of the manifold. it is actually a separate piece that threads into the manifold itself.
So you just screw it tighter?
Hi Wingman - sounds like a very similar problem to what I'm getting with my AFC. However, my wideband O2 reads out that I'm running very rich (explains the heavy smell of gas & terrible near-stalling idle). I started a thread (http://www.mazdas247.com/forum/showthread.php?t=123735794) but haven't had a single response. In the AFC sticky thread I've had some insight, but nothing definitive.
Basically, I wired up my AFC (Power, Ground, tach) and then selected only one of the 2 interfaces (for lack of a better word - the O2 and MAF wires) to connect at a time. When my O2 was the only one connected, the car "behaved" at idle. When my MAF was the only one connected, the car idled like s*** & AFR's were off the chart rich (9.0 or more).
I'm going to do a MAF and EGR sensor cleaning to see if that will remedy the problem (really hoping it does). I'll post up my results when I get to it - maybe this weekend.
Basically, I wired up my AFC (Power, Ground, tach) and then selected only one of the 2 interfaces (for lack of a better word - the O2 and MAF wires) to connect at a time. When my O2 was the only one connected, the car "behaved" at idle. When my MAF was the only one connected, the car idled like s*** & AFR's were off the chart rich (9.0 or more).
I'm going to do a MAF and EGR sensor cleaning to see if that will remedy the problem (really hoping it does). I'll post up my results when I get to it - maybe this weekend.
Sounds great, let me know
!As for my screw questions, do you know if you can just screw it tighter?
Sounds great, let me know
As for my screw questions, do you know if you can just screw it tighter?
I'm guessing your referring to the EGR tube fitting that is mentioned above? I'm not entirely sure, but if it were leaking there I would think that tightening that nut would help. It's a b**** to get to without removing anything, but I've managed to do it because like an idiot I forgot to reconnect that once when putting my whole manifold/turbo/exhaust back together. The easier way is to remove the hot-side pipe off the turbo. Not sure if there is anything that can be put on there like threadlocker to make it a better seal or not.
slo03.5msp
Member
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- 03.5 yellow msp
Its entirely possible that the maf and or o2 could be bad. The afc is changeing the signal voltage. If they are bad you won't know unless you drive the vehicle around for a couple days on the stock ecu. When my mac took a dump the car just stopped running. The mass air was going for awhile but with the ss on the car the factory ecu couldn't tell till it was dead. One thing you will notice with bad sensors is that the car will start running very rich, because it cannot properly monitor what's going on. Try checking your maf voltage and o2 voltage with a voltmeter at the sensors to make sure they are accurate.
Thanks for the tip, but those were the first 2 things that I have checked
! I changed my O2 sensor and also replaced my MAF and my car was still stalling during idle.I have also checked for possible leaks, but nothing. Thats why I was asking about that screw! Maybe my wires are badly soldier too or I dont know...
Do you only need to remove the head-shield to access the nut on the manifold?
I didn't think of that first time through (since I just got rid of my heat shield instead of dealing with it in the way all the time)...but yeah, I believe you will have to get that heat shield off too. I have a CAI on my car & stock intercooler & piping, and with the heatshield off I was able to hook my arm under the pipes, squeeze my wrist in there w/ an adjustable wrench, and tighten that nut up. Not very comfortable or easy, but I didn't want to go through removing all the damn tubing. It will be easier with the hot-side intercooler piping removed too though.
I didn't get around to getting any work done on the car yet....other than the MAF cleaning. But I haven't bothered to reinstall the AFC again yet since I'd like to get it all done & reset ECU before trying again....hopefully this weekend will yield more time!
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OK thanks, I verified quickly this morning and it seems that there is a big gap between the nut and the manifold. It is supposed to be tighten down close to the manifold? It is a huge nut that is for sure!
Also, I would like to check my PCV valve; where exactly is it located so that I can verify it is not loose?
Thanks
