Ford MAF install ?'s

[durson1]

I'm running MS2 V3 on 2.88 code on speed density fairly successfully on a 2.0L 8v Audi engine. I wanted to start experimenting with MAF. I installed and wired in a Ford 70mm MAF. I did confirm voltage output before I installed it so I know it is functional. The signal wire I ran to IAC 1-1A, and on my board I jumpered that to JS5. I then set MAF vs MAP usage to blend with MAF on Baro. I then set MAF use below 7500 rpm and Map use above 7500rpm to essentially keep it in MAF mode. The MAF correction table right know goes from 5 gps to 150 gps. I used an excel sheet from another post to figure max flow to be approx. 110 gps. all correction values are at 100% right now. Yesterday I got it to start and idle. Stepping on the accelerator made no change in the MAF value in Megatune though.
Do I have everything wired up correctly, and set up correctly? Is there no change in maf because I have all the correction values set to 100%? I thought with all at 100% it would get an uncorrected output from the Ford MAF.
Do I need to run the MAF signal thru a resistor? I'm a little lost. Any help would be appreciated. I've read the MAF section of the mega manual over and over, posts on this site, and info on Ford MAF's all over.
Thanks

[durson1]

Here is the msq and a short datalog from the first startup. Again any help is greatly appreciated.
Thanks

[FixItAgainTony]

durson1,
Looking at the log file, it does not look like the MAF reading is being seen by the controller. At low / slow throttle openings, the MAF and TPS signals look similar. A way to test the operation on the stim is to jumper the TPS signal from the stim to the MAF input location. This allows the stim to be used to help validate all of the settings in Megatune / TunerStudio for MAF operation. In the car, a voltmeter on the MAF output pin to see if the reading is as expected is also probably worth checking. I suspect that there is some sort of wiring problem that is preventing the MAF sensor output to be sampled by the controller.

Once the sensor input is sorted out, an easy way to see if MAF is being used to control the engine is to look at Gve. During MAF operation, this is forced to 100%. The MAP/baro value is created from the MAF reading, and should look similar to the MAP reading if everything is working correctly. During transient changes, there should be a minor difference between the signals. The MAP is a bit slower to respond to opening the throttle. In the log file posted, they are exactly the same; another indication that the MAF sensor is not being used.

The MAF input should probably have the same RC filter network as the TPS sensor.
MAF input > 0.0001uF (to ground) > 1K ohm resistor > 0.22uF (to ground) > Analog pin
See schematic page 2 http://www.megamanual.com/ms2/pcb.htm

If memory serves, the logic in MegaTune for MAP/ MAF operation is a little backwards. Try the following to get the system to run on MAF at all times:

Enable MAF Use => MAF/MAP blend
MAF Hardware Configuration => MAF on Baro Pin

MAP Only Above RPM (rpm) => 214
MAF Only Below RPM (rpm) => 215
Invert above MAP/MAF settings => Use above

- Charles.

[durson1]

First thanks for all the info. I did run the signal thru a 2.2k resistor after my 1st post.

I hooked up my MS to the stim and jumpered the tps signal to the input for the MAF. The MAF value changed and it works on the stim. It actually allowed me to set the correction values to achieve a response curve similar to a Ford curve for the MAF I'm using. So the controller side appears ok. I will try your suggestion of the MAF usage settings. So the settings you suggest seem to me to mean that MAP would be used above 214 rpm. Is that what you meant? But you're saying that will give me MAF use? Thats interesting.

Thanks for the heads up on everything else. I'm sure it will help alot.

As for the RC filter network is that something I would need to create in the proto area of my V3 board? I built my MS, but it worked no problem so I haven't had a reason to get too into control board layout, and circuits. In the directions for adding a barometer sensor, which is the input I'm using for my MAF signal, it says to run it thru a 1k resistor.

Anyway I will try it with the changes I made, and with the MAF usage settings you suggested and go from there. The MAF I'm using is from a small V8, and large V6 Ford. I am using it on a 2.0L 4 cyl. so the flow may not be in the range of the MAF I'm trying to use. I guess I'll see. But by watching the gauges you specified I will now know if it is working or not.

Thanks again

[grippo]

The logic for maf usage above/ below rpm was incorrect but has since been fixed and should be correct in the latest V2.890 ini file which should be used with v2.890 code.

[durson1]

So either reverse my maf-map settings or use the 2.89 code. So FixItAgainTony's advise on those settings is correct. That will save me alot of trial and error time. I'll get more time on it this weekend.

But am I correct in assuming these numbers should be reversed when not using the 2.89 code?

MAP Only Above RPM (rpm) => 214
MAF Only Below RPM (rpm) => 215

[FixItAgainTony]

durson1,
The easiest way to sort out the RPM #'s is to use the Stim and MegaTune / TunerStudio / MegaLogViewer [turn on datalogging and have MeagaLogViewer follow a live file – a really neat feature that Phil added]. Add a gauge to display Gve or watch it in the log file. Change the RPM until Gve goes to 100 => now using MAF.
On the 2.88 version of the code. I used 214 / 215 as these are below the cranking speed of 300. During cranking, fueling is determined by water temperature => MAP / MAF is not used. Above 300, the fueling control transitions to either MAP / MAF / TPS [alpha-N] depending on which is enabled. If running the 2.890 version, the RPM numbers would have to be changed.

As you noted, the capacitors form an RC filter network => used to remove higher frequency noise that may be picked up by the wiring. I placed mine in the proto area. As you have things running correctly on the stim, I suspect that there is something odd with the in car wiring. The signal does not look correct. I would check continuity from the MAF output to where it gets on the board. If that checks out, then there is a minor chance that the look up table for the MAF values was modified. This table is not accessible with the current software, but it is not too hard to write a table burner, similar to the IAT, CLT temperature tables – only the index [which table is burned] and the data would get changed. As you are using the Ford sensor, the easiest way to get back to the default is to reload the controller firmware. That is probably a good idea anyway – the latest firmware and the RPM change over logic is corrected.

- Charles.

[durson1]

Cool. Thanks. The msq and log I posted at the beginning of this were without the rc filter, and without the maf map usage settings you suggested. I added that after your first response. With all the help and insight I've received from mostly you I am sure I will be able to get it to function correctly now.

As for these numbers:
MAP Only Above RPM (rpm) => 214
MAF Only Below RPM (rpm) => 215

I meant should map above be 215 and maf below be 214?

[durson1]

So I did some stim testing. I set map above to 2001 rpm's and maf below 2000 rpm's. Ramping rpm's up and down I watched my "VE Current" gauge follw my VE table accross the 100kpa bins, then at 2001 + it switches to 100%. I made some final adjustments to my correction table to match up as closely to a voltage vs flow chart I deemed to be fairly accurate averaged against others.
This weekend I'll start it up, get it to idle, go for a drive, tweek it as needed to run, then watch the log.
Thanks for the help. I think I got it from here.

[FixItAgainTony]

durson1,
Glad to hear that you were able to get it sorted out. The stim is a brilliant bit of kit to sort out problems / understand how the system works.
If time permits, please post your experiences with the MAF. It completely transformed the way my car runs, mainly because it handles transisent changes better and does not require as much tuning (acceleration enrichment, etc). This is probably more a comment on the state of tune of my car before I went to the MAF sensor. Shifting gears / acceleration on my 30, ah 31 year old car is now like a newer modern car.

- Charles.

[durson1]

Well it worked on the stim, but not on the car. I traced out the wiring and the input I was using IAC 1-1A went to pin 27 not pin 25. The wiring harness was the only part of my kit I bought pre assembled. So IAC 1-1A and IAC 1-1B are reversed. So after getting that sorted out I now have a maf signal. I got it started and idling. The log is really long, and mostly pretty rough. I tried to back out of my garage and anything off idle my afr would lean out and the engine would die. It may also be the grams per sec numbers I'm using in the correction table that aren't quite right. At idle my maf= 3 when pulling out of my driveway maf rises to about= 7 my afr goes to 21.0 and it dies. It looks like my correction values would need to jump from 44% at idle to much higher than that in the next bin up. I have more work to do it seems.

I am wondering under "Other fuel settings" " AFR table fuel calc usage" when running speed density I ran in "use combined VE/afr table" keeping the afr out of the fuel calculatios. If I switch this to use seperate ve/afr would the afr then be included in the fuel calculations in maf mode? I ask because when looking at my log my target afr is always higher, to varying degrees, than what my afr table shows it should be.

Also I think I may need a different MAF sensor. In my MAF correction table, at idle the correction % I have is 44%. I may be able to get it to work if I can get a combination of flow and % correct. I would really like to get this to work. At idle it ran awesome. idled smooth, lower map. I have been tweeking my VE table for over a year now and it is still a little lumpy. Car runs good enough, but I think if I can get this maf thing worked out it will run like I want it to.

My log is too large to upload and I don't know how to cut just a piece of it out. My msq is attached but probably doesn't mean much without the log.

Does anyone know how to save a piece of a log? I'll take a shorter log when I have time.

[durson1]

I was able to cut a lot of the empty space out of my log using Excel, but the marks ( where it died and I restarted are gone) so where you see the rpm's drop to 0 and then back up that is a re start.

[FixItAgainTony]

durson1,
Glad you found the wiring problem. Based on your stim / versus car results, something looked a little out of place. Concerning your question about AFR, I think Al Grippo answers is on the last page of:
viewtopic.php?f=64&t=33823&start=80
Somewhere in that thread is a spread sheet I compiled on all of the known information on MAF sensors that have been posted by others. There are also some notes on reverse calculation of the MAF from the MAP / RPM / IAT – with this you may be able to use one of your old logs and a quick spread sheet formula to estimate the air flow into your car and help figure out the best size of MAF sensor for you car.

The large log files compress really well – post them as *.zip files [if possible?].

- Charles.

[durson1]

Well I got it running fairly well. I changed under other fuel settings- afr table fuel calc usage- use seperate ve/afr table. then played with the maf correction values. Only issue now seems to be my map/baro #'s. They are below my map value by about 20. eg. at idle my map value is 33, map/baro is 13. So I am in a whole different part of my afr table when driving in maf mode vs. speed density. I'll do more research on this. I could redo my afr map bins to compensate for this, but if there is just something obvious I'm missing I'd rather not do that. I don't know if this is due to my maf correction#'s or what.
I attached my log and msq. The first 70% of it is dinking around with it in the driveway. Last portion is on the road.
Thanks.

[durson1]

Adding to my above post: It seems that map/baro is being used as load calculation in my afr and advance tables instead of map. Under other fuel settings I have use map/baro for tables set to use map only. Does this setting need to be changed. I'd like to use maf for fueling, but map for my afr and advance. How can I accomplish this? Or do I just need to adjust my map bins on my tables to reflect map/baro instead of map. I thought map and map/baro were supposed to be very close except during throttle changes.

[grippo]

I answered this in your post to Megasqrt Info.