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Thread: MAF flow effects

  1. #21
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    I don't know why it would improve a situation by rotating the sensor. Not enough info. I will guess that Banks encountered some turbulence not otherwise persent, and it may present the MAF to the thrust of the turbulence. The MAF design is directional. It could be that the position that makes the problem occur may be too high a volume, and turning it could reduce the perceived volume. Goes back to what I said the first time. I could tell you what the EGR is supposed to do, but can't tell you why it does what it does when it doesn't do what it's supposed to do.

    A Diesel engine can't run lean. It can be too rich (excess fuel it can't burn completely), but that's the black smoke that gets expelled. Lean a Diesel, and it slows down. There is no "mixture". There is no controlled restriction in the intake to control the air, other than the later models, but that's for the EGR and DPF, not mixture. #2 does not require the 15:1 like gas. It's variable according to the fuel properties (which varies from kerosene to bunker oil), available heat, injection and combustion chamber design.

    Your last statement sounds like you are getting closer to understanding. At the same time, the PCM tracks the air volume trend as well as the given known volume values.

    All that said, the engine will run fine with the MAF disconnected. It will be sluggish off idle and lack power, but will still run near normal. Try it. The SES will show up and you'll get a MAF code, but it will still run and respond to pedal input.
    1985 Blazer 6.2
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  2. #22
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    Yesterday I bought another intake tube and today installed the MAF as per Banks suggestion. Tube was $75 and a PCV grommet $3 so not to expensive an exercise if it doesn't work.

    What I have found:
    1. Intake temps. appear to be about 10 degrees lower; at first this made no sense but if the EGR is staying closed it would seem reasonable/possible.
    2. EGT'S don't seem to be effected much---if anything I would have to say they are higher??? Again is it possible the EGR has changed; we have heard that the regurgatation of exhaust lowers EGT's.
    3. Any black smoke under heavy throttle has disappeared; this is in any setting of the EDGE. Big change from before where you could see black smoke when heavy on the throttle.
    4. No perceptable change in power; I'm not surprised at that but surely hope there is a decided change percieved when I hook back up and tow heavy. Before the loss of towing power was experienced I did not experience any feel of loss of power when unloaded.
    5. No codes were set.

    I'll have to hook up and tow to see if this has worked. As of now my expectations aren't real high if indeed the EGT's are a bit higher; the first thing I noticed along with the resistance to pull the normal gears after the Banks exhaust was installed.
    Need someone to tell me what wire and what voltage on the EGR valve to see if its open, closed or in between.

  3. #23
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    Quote Originally Posted by moss6 View Post
    What I have found:
    1. Intake temps. appear to be about 10 degrees lower; at first this made no sense but if the EGR is staying closed it would seem reasonable/possible.
    do you have some way of measuring plenum temps? This whole thread, and the other sure has me wanting to go out and by a new set of lawn darts. Are you sure you were talking to a Banks rep? So far, nothing that you refer to banks makes sense to me. Are you referring to IAT? If so, that is measured at the MAF sensor, not the intake, and yes, of course that will change if you mess with MAF orientation (the nuttiest idea yet IMO). But more importantly, is has nothing to do with EGR. Your IAT is the temp of air entering the box, way upstream of any egr interaction.

    Lets go back.

    If you have the stock tube, and the MAF is in the stock location, NOTHING that you do to modify your intake upstream of the element is going to change your MAF reading. I repeat, nothing.

    This whole idea that a free flowing intake will change your MAF reading for a given boost and rpm setting, is TOTAL BS. That is what the idiotic intake manufacturer morons want us to believe, and believe you me, there is no truth to it. "flows more air"? Not a chance.

    I'll help clear up MAF tuning in a diesel. If your MAF is down (significantly), whether it be because of a boost malfunction, or MAF sensor degradation, or any other mishap, fuel will be limited in proportion according to a histogram matrix that sees to it. Very simple, not complicated. Oil coating the sensor could be such an event. Oxidation of the hot wire, another.

    If you want to check it, just get onto someone with EFILive and log it. You should see 48-58 lb/min airflow (stock MAF location) in 90 degree weather, near 800 ft above sea level, using stock WOT boost settings and 3200 rpm. I will bet you fall into this category.
    Michael 04.5 SRW LLY

    custom stock intake, upsized boost tubes, Pre-turbo WMI, EFILive custom tune, Aerotech Scan Gauges.

    Go Smokeless!

  4. #24
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    Quote Originally Posted by killerbee View Post
    do you have some way of measuring plenum temps? This whole thread, and the other sure has me wanting to go out and by a new set of lawn darts. Are you sure you were talking to a Banks rep? So far, nothing that you refer to banks makes sense to me. Are you referring to IAT? If so, that is measured at the MAF sensor, not the intake, and yes, of course that will change if you mess with MAF orientation (the nuttiest idea yet IMO). But more importantly, is has nothing to do with EGR. Your IAT is the temp of air entering the box, way upstream of any egr interaction.

    Lets go back.

    If you have the stock tube, and the MAF is in the stock location, NOTHING that you do to modify your intake upstream of the element is going to change your MAF reading. I repeat, nothing.

    This whole idea that a free flowing intake will change your MAF reading for a given boost and rpm setting, is TOTAL BS. That is what the idiotic intake manufacturer morons want us to believe, and believe you me, there is no truth to it. "flows more air"? Not a chance.

    I'll help clear up MAF tuning in a diesel. If your MAF is down (significantly), whether it be because of a boost malfunction, or MAF sensor degradation, or any other mishap, fuel will be limited in proportion according to a histogram matrix that sees to it. Very simple, not complicated. Oil coating the sensor could be such an event. Oxidation of the hot wire, another.

    If you want to check it, just get onto someone with EFILive and log it. You should see 48-58 lb/min airflow (stock MAF location) in 90 degree weather, near 800 ft above sea level, using stock WOT boost settings and 3200 rpm. I will bet you fall into this category.
    If you are frustrated try to put yourself in my shoes; and now I have to avoid being impaled by lawn darts! Really if it were your truck, which towed really well with only an Edge Juice with Attitude, and you read all the attributes of adding a performance cat back system and adding some cooler air on forums like this; then put them on your truck only to find that it didn't pull nearly as well and ran higher water and EGT temps. ,what would you do. I came to this forum to try get some help in fixing the problem; plain and simple. I may not be any very good at conveying my thoughts or questions; we all have our limitations; but I try to do the best I can. I don't know what else to offer other than if contributors here really want to help, please try to tolerate some of my lack of expertise.

    Anyway to try to respond to your post:
    Yes the person I talked to was a Banks representative and when we spoke he consulted others at Banks for support of the discussion.
    As for where the air temp sensor is I don't think that the information is in the Edge literature. One thing is for sure it is not in the intake tube and taken by the MAF because the temp is always at least 25 degrees (a bit less now) higher than the ambient and I have seen it 100 degrees higher than ambient when pulling hard with the current setup. I do not have data on the highs before the cold air and exhaust install.
    I am not sure I agree with your statement that nothing you do with the MAF in the stock position can change the MAF reading. I would think that if modifications have in some what hurt power in a high load situation (ie excessive throttle opening position vs normal MAP) some odd things could occur, doknow.
    I really don't think the intake flows more air nessesarily, but it is cooler and I have tested on other vehicals and found that modifications can actually lower water column readings in the air box and intake tube locations.
    Nearly forgot; I installed the MAF with the orientation the same as stock and have not rotated it to see if there was any percievable change in performance.
    Also after stateing that I got no codes my wife got a Mass or volum air flow circuit range performance code yesterday and today. Not sure but something like P0101?? It's cleared now so I can't access it anymore.
    I had cleaned the MAF with MAF cleaner after removing the K&N.
    I don't have access to EFIlive.
    Amazeing to me that you can place the MAF in such a high flow area and see no change in performance; worse or better.
    I'd still like to know if you can check the EGR valve position with a volt meter to see if what Banks said is correct about it staying closed.
    I'll rotate the MAF tomorrow for grins to see what havoc that provokes.
    I'll also call Banks with the results and see what their take is.
    Last edited by moss6; 09-18-2007 at 17:10.

  5. #25
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    I haven't got to call Banks yet, got in too late, but I did get to do some testing on the effects of rotating the MAF sensor. To be honest I really expected this to be a inane exercise so my expectations were pesimestic at best. However the results were highly surprising as well as encourageing.
    When I rotated the MAF in an orientation such that the plug in was down stream of the air flow there was a noticeable increase in throttle response and acceleration. The EGT's also showed a decrease and the intake temps were still lower as when the MAF was relocated. Now in spite of all the negative input my hopes are up. At this point I let the computer do a MPG check and that shows that we are doing pretty good there also.
    That done I pulled over and rotated the MAF sensor 180 degrees for another try; in that position (plug in end facing upstream of air flow) response and acceleration was futher enhanced and I'm feeling better about things than I have in a good while. I let the computer do it's thing again and MPG still looks good. EGT's are also still noticeably lower as in first position, and didn't even have to let it idle a bit after pulling into the garage to let it get below 400 degrees as has been the norm.
    I realize at this point that this is not substantial evidence that the problems are cured, but I am encouraged. It remains to be seen if this will bring back the loss of towing power which was accompanied by the high temps. but I must be optimistic that I'm on the right track. Only the tow will tell.
    It is so strange that these results are so contradictory to most of what I have heard. And of course the Jury is still out, with the adapability of the PCM things could go down hill in a hurry; I prey they don't and that I once again can be one happy camper when towing the fifth wheel!
    In the mean time I hope that smell that I think I can sense in the air is baked crow.

  6. #26
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    Quote Originally Posted by moss6 View Post
    Yes the person I talked to was a Banks representative and when we spoke he consulted others at Banks for support of the discussion.
    As for where the air temp sensor is I don't think that the information is in the Edge literature. One thing is for sure it is not in the intake tube and taken by the MAF because the temp is always at least 25 degrees (a bit less now) higher than the ambient and I have seen it 100 degrees higher than ambient when pulling hard with the current setup. I do not have data on the highs before the cold air and exhaust install.
    same as the rest of us. Believe it or not, the MAF is the site of that reading
    Michael 04.5 SRW LLY

    custom stock intake, upsized boost tubes, Pre-turbo WMI, EFILive custom tune, Aerotech Scan Gauges.

    Go Smokeless!

  7. #27
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    While im not an expert nor do I claim alot of knowledge relocating the sensor should help because there is more intake air, as has been said if you had a stock system an you tried it the O2 sensor would foul you up by reporting a rich condition, however with more air then normal an it not getting reported correctly the O2 sensor is still fouling you up by now reporting a lean condition? I dont know if that would hold true for a diesel engine or not but that would be one reason I think relocating the sensor would work.
    93 GMC Sierra 2500
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  8. #28
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    Quote Originally Posted by killerbee View Post
    same as the rest of us. Believe it or not, the MAF is the site of that reading
    Think about it, 100 degree rise from point of entry thru the filter box and then thru a portion of the intake tube; not a chance.

  9. #29
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    Quote Originally Posted by 93GMCSierra View Post
    While im not an expert nor do I claim alot of knowledge relocating the sensor should help because there is more intake air, as has been said if you had a stock system an you tried it the O2 sensor would foul you up by reporting a rich condition, however with more air then normal an it not getting reported correctly the O2 sensor is still fouling you up by now reporting a lean condition? I dont know if that would hold true for a diesel engine or not but that would be one reason I think relocating the sensor would work.
    Seems 180 from those who know eh.

  10. #30
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    Quote Originally Posted by moss6 View Post
    Think about it, 100 degree rise from point of entry thru the filter box and then thru a portion of the intake tube; not a chance.
    think again. How about a 150 degree rise? Yes. Before the air ever reaches the airbox. I have logged over 240 F.

    I am not trying to make this hard for you. I am always trying to help. But if you don't want to hear what is being said, then there is nothing more I can suggest.
    Last edited by More Power; 10-09-2007 at 20:27.
    Michael 04.5 SRW LLY

    custom stock intake, upsized boost tubes, Pre-turbo WMI, EFILive custom tune, Aerotech Scan Gauges.

    Go Smokeless!

  11. #31
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    Quote Originally Posted by killerbee View Post
    think again. How about a 150 degree rise? Yes. Before the air ever reaches the airbox. I have logged over 240 F.

    I am not trying to make this hard for you. Perhaps you would care to read this article. I am always trying to help. But if you don't want to hear what is being said, then there is nothing more I can suggest.
    This must be a joke; if not I think you just shot down any credibility of your posts.

  12. #32
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    Quote Originally Posted by killerbee View Post
    ....But if you don't want to hear what is being said, then there is nothing more I can suggest.

    good luck. As a parting tidbit, consider what happens to MAF when IAT gets to 100 over ambient. I tried.
    Michael 04.5 SRW LLY

    custom stock intake, upsized boost tubes, Pre-turbo WMI, EFILive custom tune, Aerotech Scan Gauges.

    Go Smokeless!

  13. #33
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    Quote Originally Posted by killerbee View Post
    think again. How about a 150 degree rise? Yes. Before the air ever reaches the airbox. I have logged over 240 F.

    I am not trying to make this hard for you. Perhaps you would care to read this article. I am always trying to help. But if you don't want to hear what is being said, then there is nothing more I can suggest.
    after reading this I can agree with alot of your points, However from my reading of the posts he has cooler outside air coming in the air box, it should be able to pull enough air to keep that particular problem at bay, an he is not running a lly engine, but a lbz I dont know the difference in them really but I believe that would also make a difference.
    93 GMC Sierra 2500
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  14. #34
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    I can't see what Moss6 has, there is no signature despite suggestions to create one. If it is an LBZ, it has an additional IAT reading pre-plenum, IAT2. But who knows which one is being referenced here?

    The LBZ stays somewhat cooler, but still gets up to 180 or so at IAT1 (airbox) in this neck of the woods. I have a IAT2 sensor in my LLY, and have documented 240 F. That is under very stressful conditions. Normally it stays under 200.
    Michael 04.5 SRW LLY

    custom stock intake, upsized boost tubes, Pre-turbo WMI, EFILive custom tune, Aerotech Scan Gauges.

    Go Smokeless!

  15. #35
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    If there is anyone out there who knows the voltage readings for the EGR valve and what wire to tap on to I'd still love to have the info.
    Also I think its good for all of us to know that if we are in need of some good hot water while out in our trucks (for coffee, tea or whatever) all we have to do is stick a cup in the filter box, and bingo you get boiling water!! Whoops, almost forgot, this only works in "extreme conditions" like er driving thru Hell; and I guess you wouldn't be needing that boiling water there anyway---sorry.

  16. #36
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    Although the truck is running much better now I am still getting MAF codes which I would like to take care of, other than letting the Edge cancel them with each start up. Wonder what effects the Finger Stick would have on that or if it can only be taken care or by remapping which I don't want to go to that alternative. Probably need some help from Kennedy or Finger here. Still need some info in order to monitor the EGR valve position to evaluate the need or not for the blocker plate.

  17. #37
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    Question Loss of throttle response after moving MAF sensor.

    This post seems interesting to me especially since it involved discussions around Bank's recommendations. I installed a Banks Ram Air Intake system and noticed a loss in off the line throttle response. I was wondering if relocating the MAF as required with the Bank's system was the cause of this. I spoke with a Bank's tech and they claimed I should have noticed an increase in throttle response. They have not offered much of assistance in troubleshooting my problem. I was thinking of trying to modify the Bank's system to relocate my MAF closer to where it originally was. If this doesn't work, I plan on removing the Banks Ram Air intake and going back to stock with the K&N. Has anyone had this experience or can give me some advice?

    DieselMax403
    2003 GMC Sierra 2500 HD 4x4 Crew Cab SLT D/A, Banks TLC Stinger Kit, Stock XM Radio, Wheel-to-Wheel Go Rhino Chrome Step Bars, Bushwacker Bed Rail Caps, Line-X Bedliner, 265/75 E REVO AT's on 16 x 8 Weld Cheyenne 8 Wheels

  18. #38
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    Quote Originally Posted by DIESELMAX403 View Post
    This post seems interesting to me especially since it involved discussions around Bank's recommendations. I installed a Banks Ram Air Intake system and noticed a loss in off the line throttle response. I was wondering if relocating the MAF as required with the Bank's system was the cause of this. I spoke with a Bank's tech and they claimed I should have noticed an increase in throttle response. They have not offered much of assistance in troubleshooting my problem. I was thinking of trying to modify the Bank's system to relocate my MAF closer to where it originally was. If this doesn't work, I plan on removing the Banks Ram Air intake and going back to stock with the K&N. Has anyone had this experience or can give me some advice?

    DieselMax403
    If you want to try relocating the MAF to a more stock position on the Banks system it is very easy. Just opposite of what I did with the stock setup. Take a 1 3/8" hole saw and on a bench grinder grind down the outside area of the teeth until the OD is about 1 11/32"; this makes a cleaner and tighter hole. Drill the hole where you want it in the air box housing and install a grommet in the hole that will accept the MAF and provide a very tight fit; with this set up you can actually rotate the sensor into any orientation you want in relation to the air flow. I found this orientation thing to change performance pretty dramatically. The grommet I used was by Spectre Performance for 1 1/4" filler hole, I think it was for used as spark plug wire guides???? Sorry I don't have enough of the package left to provide a part #, think the Guy got it from the dress up section at the Auto zone I was at looking for a grommet with an ID hole that was big enough. The fit will bevery tight but that is what you need. Good luck, I'd like to hear about the results.
    My problems aren't solved yet----still looking and have another Edge on the way---my MAF back to the stock position even though it ran so much better ---I didn't like all the constant coding, and no-one seemed to acknowledge how or why in regards to the power increase, much less have any ideas on fixing the codes with the MAF in such an unorthodox position. Oh well.

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