Big MAF question for pre-March '90 CQ
03-09-2014, 06:08 PM
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Big MAF question for pre-March '90 CQ
My intake boot is getting pretty worn and I'm considering replacing it with a silicone 034 hose that's intended to be used with a big bore MAF sensor such as on the AHA motor. I'm looking at a couple of parts and would like confirmation from someone who knows whether they can be used together in my application. My Coupe Quattro is an early '90 model with Hitachi ISV.
I understand if I go with a three terminal style MAF sensor that I will have to fabricate a harness that incorporates an adjustable potentiometer that lets me dial in the CO at idle. I also understand that the earlier 054 style MAFs have an adjustment for this built-in. I have seen lots of posts indicating 078133471A is the best MAF to use, but the orientation of the screws seem to be different ("backslash" diagonal) compared to my current MAF ("forward slash"), and I found this 078133471 (without the "A") that has the same orientation and would allow me to use a four-terminal MAF to plug into my existing harness.
What I would like to know is if the bore of this combination with 078133471 sensor is the same as the 078133471A that folks seem to recommend. I'd also like to understand whether the orientation of the screws is the only physical difference between these two types.
All the posts I've found on this are pretty old and it seems like a lot of the posters aren't active anymore, so I thought I'd start with a new post of my own asking for input.
I understand if I go with a three terminal style MAF sensor that I will have to fabricate a harness that incorporates an adjustable potentiometer that lets me dial in the CO at idle. I also understand that the earlier 054 style MAFs have an adjustment for this built-in. I have seen lots of posts indicating 078133471A is the best MAF to use, but the orientation of the screws seem to be different ("backslash" diagonal) compared to my current MAF ("forward slash"), and I found this 078133471 (without the "A") that has the same orientation and would allow me to use a four-terminal MAF to plug into my existing harness.
What I would like to know is if the bore of this combination with 078133471 sensor is the same as the 078133471A that folks seem to recommend. I'd also like to understand whether the orientation of the screws is the only physical difference between these two types.
All the posts I've found on this are pretty old and it seems like a lot of the posters aren't active anymore, so I thought I'd start with a new post of my own asking for input.
03-09-2014, 10:51 PM
#2
AudiWorld Member
My intake boot is getting pretty worn and I'm considering replacing it with a silicone 034 hose that's intended to be used with a big bore MAF sensor such as on the AHA motor. I'm looking at a couple of parts and would like confirmation from someone who knows whether they can be used together in my application. My Coupe Quattro is an early '90 model with Hitachi ISV.
I understand if I go with a three terminal style MAF sensor that I will have to fabricate a harness that incorporates an adjustable potentiometer that lets me dial in the CO at idle. I also understand that the earlier 054 style MAFs have an adjustment for this built-in. I have seen lots of posts indicating 078133471A is the best MAF to use, but the orientation of the screws seem to be different ("backslash" diagonal) compared to my current MAF ("forward slash"), and I found this 078133471 (without the "A") that has the same orientation and would allow me to use a four-terminal MAF to plug into my existing harness.
What I would like to know is if the bore of this combination with 078133471 sensor is the same as the 078133471A that folks seem to recommend. I'd also like to understand whether the orientation of the screws is the only physical difference between these two types.
All the posts I've found on this are pretty old and it seems like a lot of the posters aren't active anymore, so I thought I'd start with a new post of my own asking for input.
I understand if I go with a three terminal style MAF sensor that I will have to fabricate a harness that incorporates an adjustable potentiometer that lets me dial in the CO at idle. I also understand that the earlier 054 style MAFs have an adjustment for this built-in. I have seen lots of posts indicating 078133471A is the best MAF to use, but the orientation of the screws seem to be different ("backslash" diagonal) compared to my current MAF ("forward slash"), and I found this 078133471 (without the "A") that has the same orientation and would allow me to use a four-terminal MAF to plug into my existing harness.
What I would like to know is if the bore of this combination with 078133471 sensor is the same as the 078133471A that folks seem to recommend. I'd also like to understand whether the orientation of the screws is the only physical difference between these two types.
All the posts I've found on this are pretty old and it seems like a lot of the posters aren't active anymore, so I thought I'd start with a new post of my own asking for input.
remove the sensor
get the 4 connector one with flat bottom (92-93 a100 has it)
mate them you are done
you can use the 3 connector sensor but then you have to...... read the pdf
http://quattro4life.com/download/pdf...version_V2.pdf
03-10-2014, 05:55 AM
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Thanks for the PDF.
Regarding the sentence above, I understand there are at least two different big maf housings, 078133471A which is best if you intend to modify it for even greater flow, and 078133471 (without the A) that is also a big bore maf but for some reason is not as desirable to modify it for even greater flow.
I don't know if the difference is the screw orientation, or something else. Do you know? I'm asking because the one in which I'm interested and have posted a picture of, does not have the "A" at the end. All the ones I find with the A in the part number, do have the opposite screw orientation, say 11 and 5 o'clock. I believe that means that I would have to go with the three terminal sensor (because I have seen no four terminal sensors with that screw orientation) and use the adjustable pot custom harness.
Another clarification I'd like to get is whether the four terminal sensor I posted the picture of has a screw under the round cap on the upper left that can be used to adjust the CO, in the same manner that the separate potentiometer harness is used for the three to four wire harness. I looks liked there is a metal plug covering the screw, since it's not supposed to be messed with in normal use.
Regarding the sentence above, I understand there are at least two different big maf housings, 078133471A which is best if you intend to modify it for even greater flow, and 078133471 (without the A) that is also a big bore maf but for some reason is not as desirable to modify it for even greater flow.
I don't know if the difference is the screw orientation, or something else. Do you know? I'm asking because the one in which I'm interested and have posted a picture of, does not have the "A" at the end. All the ones I find with the A in the part number, do have the opposite screw orientation, say 11 and 5 o'clock. I believe that means that I would have to go with the three terminal sensor (because I have seen no four terminal sensors with that screw orientation) and use the adjustable pot custom harness.
Another clarification I'd like to get is whether the four terminal sensor I posted the picture of has a screw under the round cap on the upper left that can be used to adjust the CO, in the same manner that the separate potentiometer harness is used for the three to four wire harness. I looks liked there is a metal plug covering the screw, since it's not supposed to be messed with in normal use.
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