MSpnp2 base tune review please

Trogdor

5 Year Member
Aug 30, 2018
109
65
38
Anna, TX
Hello,

I'm helping my friend with his MSpnp2 installation. He has a 1991 5.0 AOD and is upgrading to a 351W engine. Combo is as follows:

  • 351W roller block
  • AFR 185 heads
  • Not sure on compression, but built for naturally aspirated
  • 1.6 roller rockers
  • Stock Ford ignition and TFI mounted on a Ford distributor
  • TFS intake manifold
  • 42 Lb/hr green top injectors (eBay, so we'll see how these work out)
  • BBK in fender CAI
  • 1994 Cougar 3.8L MAF
  • 70mm BBK TB
  • Custom cam, high 220's duration at 0.050" and mid .550" lift both intake and exhaust, low 110's LSA
  • Single electric fan
  • 1 5/8" long tubes with O/R X-pipe into Spintech mufflers
  • Beefed up AOD, 2600ish stall
  • 4.10 gears
This is my first experience with Megasquirt and TunerStudio. I have several years with GM LSx based computers and I have some experience with the Quarterhouse and TunerPro on my own car. I read as much as I could on the MS platform and what needed to be done to get the car to run with it. He wants to keep the MAF and have the MS control the electric fan. The MS he bought is from DIYAutotune and the model number is MCPNP2-EEC4A8, fw rev .3.3.1, inside the base board is version 1.2 and the green board is version 1.3b.

We will be using some of the wires coming from the options plug:

  • Wire 05 - Chassis ground. Should this wire be grounded to where the factory A9P was grounded?
  • Wire 13 - Launch control input. I'm using this for my A/C idle up input. I moved jumper J3 in the MS and it will be tied into pin 10 of the EEC harness.
  • Wire 19 - MAF sensor signal. I installed a jumper inside the MS from the external MAP pin to the ADC1 pin. Option wire 19 will be connected to pin 50 of the EEC harness.
  • Wire 21 - Oxygen sensor input. My friend had an Autometer WBO2, so the blue + analog output wire from the WB will go here. I did change jumper J6 in the MS to reflect this.
  • Wire 22 - Signal Ground. Here I'll connect the - black analog output wire from the WB and the MAF pin 9 wire from the EEC connector.
  • Wire 24 - Output 1 relay control. This wire I'm going to connect to the fan relay 85 terminal, the one that would be on the other side of the relay coil 86 that is getting a 12V switched +. We are also going to use a second relay to turn on the fan with a signal from the A/C clutch from pin 10 of the EEC connector.
  • Wire 25 - Output 2 relay control. We are going to use this one for the A/C WOT cutoff relay and connect it to pin 54 of the EEC connector.
Does the above wiring seem correct, or are these some changes you would recommend?

I'm also attaching a base tune file that I put together to reflect all the information above. Could someone please take a look at it and comment on any changes that I need to make?
 

Attachments

  • 351 Base tune.msq
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Last edited:
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update the firmware to version 4.3.4

I will have to take a look when I have more time but it seems you have a handle on it
Thank you. I'm guessing I need to be connected to the MS and have an internet connection at the same time to upgrade the firmware?

Also I could not find a firmware version 4.3.4. The newest I could find was 3.4.4. Is this the one I need to download? https://www.msextra.com/downloads/ms2-extra-3-4-4-release/
 
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Yes it is. 3.4.4 you can download it you do not need an internet connection during the update process
Thank you, I'll download the firmware and update the MS. Have you had a chance to look over the file? This being a new engine I want to make sure it starts and runs pretty quickly and not wash the cylinder walls with fuel.

I did notice that I probably need to change the "Fixed Advanced" dropdown to "Fixed Timing" for the first start up. We will do our best to get the distributor lined up to #1 cylinder at 10 degrees BTDC, so should I change the "Timing for fixed advance" to 10 degrees as well? I also believe that we need to keep the spout connector in as the car will not run without it using the MS.

EDIT: I think I need to change the voltage input port in the tune file from Knock to Baro since I'm using options wire #19 for my MAF input. Do I need to send power and ground to the MAF, or is that being taken care of by the MS? I think it would since there should be power on pin 37.

I'm starting to second guess my WB settings. Right now I have the algorithm set to Simple, but should I have it set to PID? Also should I have EGO Sensor Type set to Disabled for the first fire up so that the MS would not try to adjust the fueling? Then turn it back to Single Wide Band once I get the fueling more in the ballpark?

I have the Stochiometric parameter set to 14.1:1 since the fuel around here is E10. Do I need to also make the AFR Table 1 reflect this, or is that table just based on an E0 stochiometric ratio for gasoline? Sorry, I'm just used to tuning in Lambda and don't really worry too much about what gasoline/ethanol blend is in the tank.

Should I enable sequenced batch fire?

Right now I have the Squirts per Engine Cycle set to 4. Would 2 work better in this application?

Right now the IAC is set to inverted, I did not change this. Keep it this way?

Again, sorry for all the questions, just trying to minimize the inevitable troubleshooting that always happens when changing a bunch of parts during a build,
 
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MS2pnp will need the valve set to inverted in most cases

I set squirts to 2, this gives you more range on the injector and minimises the effect of small PW with large injectors at idle

you cannot use sequenced batch fire with a TFI on ms2 to my knowledge

I use 14.7 as stoic for all fuels... the WB does not care the ethanol content and is just multiplying lambda by 14.7 in most WB anyway.. I dont get too caught up on it. Set the REQ FUEL to reflect the E10 note the value it provides then change stoic back to 14.7 and manually input the REQ FUEL value you recorded.

I use PID P=25-40 D=20-45 I=1-5
I usually start with 40 20 1 respectively this works well

mark 20* with a grease pen set fixed timing to 20* set offset in software to 10* leave the spout in, adjust distributor until 20* read on balancer. your good to go..

I have not had a chance to look at the file.
 
MS2pnp will need the valve set to inverted in most cases

I set squirts to 2, this gives you more range on the injector and minimises the effect of small PW with large injectors at idle

you cannot use sequenced batch fire with a TFI on ms2 to my knowledge

I use 14.7 as stoic for all fuels... the WB does not care the ethanol content and is just multiplying lambda by 14.7 in most WB anyway.. I dont get too caught up on it. Set the REQ FUEL to reflect the E10 note the value it provides then change stoic back to 14.7 and manually input the REQ FUEL value you recorded.

I use PID P=25-40 D=20-45 I=1-5
I usually start with 40 20 1 respectively this works well

mark 20* with a grease pen set fixed timing to 20* set offset in software to 10* leave the spout in, adjust distributor until 20* read on balancer. your good to go..

I have not had a chance to look at the file.

Thank you for your help. I'll be over at my friend's this Saturday for the first start up. Did you get a chance to look at the file?