MAF flow effects

[DmaxMaverick]

5 wires. 1 ground, 2 each for the temp and velocity, or something like that. Maybe 1 and 3. I could dig up the diagram, but it's pointless.

If the PCM "sees" more air passing through the intake, it WILL NOT add fuel because of this. It may expedite fueling from idle, if it detects the airflow sooner than OEM. Still, several other input values have to be "seen" before more fuel is added. If the PCM "sees" more air, and can't make sense of it (no other input values changed), it will assume an error.

Changing any part of the intake system can (not necessarily will) change the dynamics of the airflow. Making more air available to the intake by modifying the tract can increase the perceived MAF. It won't, however, increase fueling in and of itself. More fuel is "requested" when you increase TPS input, but you won't get it if all the other input values aren't in line.

[moss6]

Great input that, thanks! Don't know what TPS is though, help.

Another question; what effect do you think that the MAF's orientation to the the direction of flow has on its readings. That is that Banks recommended that the MAF sensor be rotated 90 degrees from its original orientation to the flow in the intake tract. Could that be something that would offset the drastic change in the amount of flow with the new location in the intake tract?
Also does it seem possible that the relocation could make the EGR stay closed?
And one more does a lean mixture in a diesel create more heat as it does sometimes in a gas engine?

[jbplock]

Don't know what TPS is ...

TPS - Throttle Position Sensor

[moss6]

I guess that makes sense in the relation to the loss of power, as load is increased throttle position has to be linearally greater to maintain a given speed. If flow across the MAF does not correspond then additional fueling is not provided????

[DmaxMaverick]

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.

[moss6]

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.

[killerbee]

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.