Digital Immigrant

a91what · May 20, 2019

Lol, you do not have to use all the curve points in TS. You can input the first 35 and make the rest equal the final value.

After that the entire VE1 table (enable ve1 as trim table in maf options) need to be set to 100. You will adjust up and down from 100 to adjust fuel.

I'm well versed in maf on megasquirt si np worries.

Freeman2005 · May 20, 2019

I need a little more explanation--like which end of the transfer curve do I start with when putting it in TS and do I change the voltages to match my transfer curve. I can't find any of this explained in TS or elsewhere. Sorry to bother you with my ignorance.

a91what · May 20, 2019

OK I went ahead and fixed it for you..

I also changed the AFR table over to Speed Density, once you have the car driving and datalogs taken we can build the AFR,IGN tables for the MAF load values.. its easy to do but we want to be sure before we begin that the numbers make sense.

The easiest way to tune in MAF mode is to tune the VE1 trim table, this way you dont have to touch the MAF curve at all.

I used a transfer curve from efidynotuning.com from a 3.8l thunderbird/cougar 70mm .... this is a common swap is this the one you used??

Freeman2005 · May 20, 2019

Mine came from the 5.0 T-bird. I got my curve from the same place.

Freeman2005 · May 20, 2019

Okay I managed to build the curve--but I have to go to work. Will do more later today.

a91what · May 20, 2019

Ok the curves that they supply are given in KG/HR so we have to multiply them by 0.277777778 to get to the g/sec value that the MS needs. once we do that in an excel sheet then we can begin moving them over to the MAF curve. If you dont alter them into g/sec then bad things happen.

Stock 91' - 93' MN12 5.0L

Voltage	Flow	g/sec
16	965.39	268.1639
5	965.39	268.1639
4.75	840.24	233.4
4.5	727.45	202.0694
4.25	626.38	173.9944
4	535.45	148.7361
3.8	470.18	130.6056
3.6	410.62	114.0611
3.4	356.75	99.09722
3.2	308.28	85.63333
3	264.56	73.48889
2.8	225.27	62.575
2.6	190.42	52.89444
2.4	159.68	44.35556
2.2	132.44	36.78889
2.1	120.08	33.35556
2	108.67	30.18611
1.9	97.9	27.19444
1.8	87.76	24.37778
1.7	78.57	21.825
1.6	70.02	19.45
1.5	62.1	17.25
1.4	54.81	15.225
1.2	41.51	11.53056
1	30.42	8.45
0.8	21.86	6.072222
0.6	15.52	4.311111
0	15.52	4.311111

I have altered the curve in this tune for you along with setting it up for your first drive.

Freeman2005 · May 20, 2019

Okay, I loaded that tune and it didn't want to idle, so I started increasing the figures in the VE1 table and it settled out. Got it to idle smoothly but cannot accelerate. As soon as I touch the throttle, it goes very lean and wants to die. I'm clueless.

a91what · May 20, 2019

Likely the curve is just close enough for it to run. How do you have the MAF plumbing run? Air box or is the filter directly on the end of the maf? The curve is from the stock location of the maf with the stock inlet design.
We need to bump the maf curve up. You are moving more air in g/sec than the curve has in it at the data points.

EDIT: I just got home and looked at the datalog, you are not getting the MAF input. There is no voltage on the input you have set, now the MAF requires that it gets 12v and ground... did you wire those in during the install?

Freeman2005 · May 21, 2019

When I originally installed the MAF a couple years ago with the A9L everything worked fine. I had power and ground. Of course that power and ground came from the A9l, so I don't know if the MSPNP is providing it or not.Seems like it would as the injectors also got their 12v from the ECU previously. I'll check the voltage at the plug for the MAF. Could be that the pins on the 26 pin have pushed back and aren't making contact. That plug is a cheap piece of crap and every time I have it out several pins are pushing back. Just checked--it has 12volts. Will check the plug at the ECU to see if the pins pushed back later.

I'm using the stock Ranger air filter box with the MAF mounted to the box, a 135 degree bend of silicone tubing to the Explorer throttle body and Explorer intake.

a91what · May 21, 2019

Copy that, have you confirmed jumpers in the ecu?

Freeman2005 · May 21, 2019

I checked continuity between the pins 26, 22 and the plug for the MAF and they are good. I checked the jumper from ADC2 to EXT. on my board and it looks good. The pins don't appear to be pushing back in the connector. Going to disconnect the jumper and reconnect.

Freeman2005 · May 21, 2019

Completed a diagnostic of the MAF. Voltage and grounds are good. To check the signal from the MAF I had to let it idle and the voltage fluctuated from .6 to about 1.2 as the idle fluctuated. I'm going to hook up TS again and see if I'm getting the MAF signal.

Freeman2005 · May 21, 2019

Upon further research I found that the MAF I purchased back in January of 2015 was for a 1990 Mustang 5.0. The OEM part number list covers a bunch of vehicles, so I don't know if it matters. I did the conversion to g/sec for the Ford '91 Foxbody and tried those yesterday with no change--in fact it was worse. I put your numbers back in the curve.
Cleaned the MAF again thinking maybe sitting there without voltage it gathered some varnish. No change. All I have to do to get it to idle is bump the idle from 100 to 140 on the VE1 and it idles smooth but leans out when I push the throttle at all.

a91what · May 21, 2019

I still dont see any voltage coming in on the MAF input. you may be bypassing the ADC circuit the way you have that wired in.. put the jumper back in place for the "knock" input and take the MAF signal into pin knock pin-10 on the 26 pin connector.

I would do this first to rule out anything else I dont see ADC7 on the datalog reporting useful information so thats an issue

Freeman2005 · May 22, 2019

I put the original jumper on the ADC7 pins and connected Pin 10 on the options connector to the MAF output signal. No change except maybe that the MAF voltage on the transfer curve is stuck at 5 volts. ADC7 on the datalogs sits at 1023. I reloaded a previous SD tune to see if I am dealing with a vacuum leak and it was perfectly normal. Any other ideas?

a91what · May 22, 2019

Adc7 does not seem to be reporting a voltage signal

Freeman2005 · May 28, 2019

I wanted to use the truck last Friday so I loaded a previous SD tune and left the MAF plugged in and then drove 45 minutes while logging. I had put a gauge for ADC7 on my dash and it was registering signal the whole time which meant the MAF was outputting a signal. Feedback from MC suggested I should check my sensor grounds and I'm trying to clarify what that means. The ECU and the MAF are grounded to the original grounding point for the ECU. Bad? Should I move grounds for the sensors away from the ECU ground? I also loaded the tune for the MAF later and same as before it idles badly and won't accept throttle input.

Freeman2005 · May 5, 2020

Well, you probably thought COVID-19 got me but not yet. I finally decided to lick the MAF issue. It turns out that the crappy connector on the ECU keeps letting the pins push back which kept the MAF signal from getting to the ECU. Finally, it starts, runs and drives, but running very lean--like 19-20 at idle. Later today I can get a longer drive on it. Where do you suggest I start with the tuning on the MAF?

Freeman2005 · Jul 14, 2020

a91what said:
The jumper is correct, you will need to do this and intercept the input from the MAF and take it to the EXT [external input] for the ADC input. or you can solder a jumper wire from the pins inside the case...

The advantage of using MAP for spark for now is that table is tuned... once you have a nice long datalog i can show you how to build a timing table in MAF from the info obtained in MAP.

I finally got the MAF installed and tuned pretty well. I've still got an annoying stumble under hard acceleration at 3000RPM and up. Coils are good, new double plat. plugs, plug wires checked good, CPS swapped and it's still there. Anyway, what I wanted to pursue now is the MAF ignition table. If you have time throw me a hint on how to do that. Thanks!

a91what · Jul 14, 2020

I'll take a look, do you have mlvms or mlvhd? We need to build out a histogram, I figure it's better to teach how than to give the answer.

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