MAF flow effects

[moss6]

I think that possibly there is still a misunderstanding of my intake; lets give it another try so there can't be any doubt of what it is.

The intake tubing and billows from the air filter box to the turbo is completely stock, no change in any way.

The air filter box is stock, with the exception that forward upper quarter around the deflection vanes is removed to provide a more direct route for the added 3" supply to flow thru.

A 3" aluminum dryer vent is used to transfer air from the air dam hole (where the recovery hook was removed) running up and thru an enlarged hole behind the headlight and then entering the air filter box enclosure.

The original air breathing holes into the fender well cavity were enlarged and provided about 3 additional square inches of breathing area.

Additional sealing was done around the air box to prevent any air from the engine compartment from entering the air box.

Thats it, a pretty basicly stock system; and really, sans the air filter box the Banks intact tract routing and size is pretty much a mirror of the stock system also.

That cleared up--I hope; it seems a very DRASTIC change moving the MAF from an inside bend location (relatively shielded) to a point where it is getting a direct hit, if you will, from the incoming air charge. From what I have learned here that would seem to really drive things bonkers, no? That is why there would seem to be much more to the system than meets the eye or common conception of its scope.
I notice that there are five wires at the MAF so I presume that it is sending out four separate signals to the PCM.
1. Air flow
2. Air temp. ?
3. ??
4. ??

1. More air flow=more fuel -----provided the criteria is met?
If more air flow is detected but load is light what happens?
In a gas engine a lean mixture equals more heat many times, is it the same with a diesel?
2. Air temp ??? what does the PCM do with that, if indeed that is one of the MAF signals?
3. & 4. Can't ask the question because I don't even know what they are or if they exist.

Bottom line is, I don't mind modifing if I've some grasp as to the workings of what I'm modifing----but in this case it is evident that I don't have a clue. Also it might even be entirely on the wrong track toward correcting my elevated EGT's, water temps, and loss of towing power.



Still need help guys!!!!

[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.