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MS3Pro PnP Build Thread

3120 Views 97 Replies 4 Participants Last post by  eschaider
Hello everyone,

First off, this thread is for a 96-98 GT and not Terminator Cobra. This sub-forum has a lot more activity so I was asked to create my build thread here.

I had an issue with my car, most likely due to weak ignition. I spoked to Ed and we agreed that it would be best to upgrate to a MS3 ECU and IGN-4 coil packs to replace the OEM stuff. Of course, the MS3 opens up a world of possibilities and I want all the bells and whistles, one step at the time.

Here it is
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The first thing I did after plugging it in, is upgrade the firmware to 1.5.2. I don't know why it shipped with 1.5.1 since the newer version is older than the release date of the ECU, but it was straightforward. I noticed the radiator fan would come up as soon as I turn the key on. It was not like that with the OEM ECU. It did a lot for debugging, the guys at DIYAutoTune were REALLY helpful and they replied pretty much instantly. Turns out I had a dead transistor and had to ship the ECU back for repair. They repaired it the next day they received it, but the whole round-trip took 3 weeks because I'm from Canada.

Meanwhile, I had the time to install my Spartan 3 wideband controller from 14point7. Allan (the owner of 14point7) was also helpful and answered all my questions. I got two wideband and two controllers, so one for each side. They are wired to the MS3 via CAN BUS. The instructions on how to set up all this were very good. In fact, everything worked on the first try! I emailed Allan to congrats him on the product and instructions and somehow turned a bad day for him into a good day. It's nice to sometime contact the people behind a company to tell them when we are happy, not only when things go bad. I also set up the controller to start heating the sensors when the engine has been running for about a minute. This is supposed to improve the life of the sensor because they won't be hit with cold condensation while they are hot.
Here is the controllers, next to the J&S Vampire. All this is under the passenger seat
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Next was tuning the idle. I managed to solve an issue I had with the OEM ECU since I converted the car to an automatic transmission (2016). When it's cold, and I get it in gear, it would stall. I searched for years to open up some more of the IAC when in gear with the OEM computer but it wasn't possible. Turns out the solution was so much easier. I had 14* timing at idle. I bumped it to 18* and voila, no more stalling when cold.
Another thing that helped to stabilize the idle a lot is getting the injector dead time correct. I had not touched this configuration from the base tune by DIYAutoTune and was trying to let VE Analyzer build a VE table and the numbers were all over the place and constantly changing. The car would also backfire, shake, ran terribly. All that was solved by having the correct injector dead time.

Next up was finally getting to the ignition. Once again, I listened to Ed's recommendation and got MSD 8.5mm wire for the Ford/Hemi pro stock.
I decided for fun to test the wires with an oscilloscope and compare them to the OEM wires. I was quite surprised at what I saw, and have no explanation for it. If someone can enlighten us I would be glad.
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MSD wire is the yellow line, OEM wire is the blue line. I simply sent a 5V square wave using an Arduino and measured at the other end of the wire. The patterns are completely different and I would love to know why, and I know one is more desirable than the other.

Fitting-wise, I had issues with cylinders #2 and #3. There was no way the tubes would clear the Kenne Bell inlet, even cut at the shortest. I ended up removing the boots from the OEM-like wires, and used them on the MSD wire.
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I went ahead and measured everything, made the wires, and checked the resistance (under 50 ohms per foot all the time), but after I had 6 wires all said and done, the seventh one had resistance in the kilo-ohms, sometimes even mega-ohms. It took me a couple of minutes to figure what was wrong. Turned out the wire wasn't crimped at the assembled spark plug side from MSD!
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This is what it should look like
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I assumed this was a fluke and proceeded to the next one. Same thing! I lost confidence, and good thing I did, all 8 of them weren't crimped! It's quite a job to remove the insulator and put it back in place, especially when the wires are fully assembled and the tube has to come from the side where it's not crimped before installation, except now it's crimped. There was a lot of grease used to be able to slip everything back into place which doubled the time required to do the job that was almost finished. I don't know if they are designed like that (I hope not), or if someone didn't do his job on my particular set. Learn from my mistake and check yours!

Here's the bracket I made to bolt the driver-side coil-pack since OEM is 4 bolt and those are 3 bolts, and not at the same location.
Automotive fuel system Motor vehicle Gas Auto part Fuel line

I already had a custom-made bracket for the passenger side coil pack, I simply had to drill 2 more holes (and reused one)

I have two pressure sensors ordered (one for fuel pressure and the other for oil pressure). I will keep this updated as I work on this project. My plan is to use the option connector on the MS3 to wire those sensors.
Pin A will be ground, pin B will supply 5V to both sensors, C will be signal from the fuel sensor and H will be oil pressure.

That's it for now, I appreciate feedback, suggestions, comments, questions, etc


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The "Ignore MAT Correction During ASE" seems like it ought to be set to ON, as you have done, Michel. This is, after all, the issue that you are wrestling with and with the switch set to "ON", as you have, my expectation would be to have no MAT correction applied, yet yours seems to attempt to apply a correction and leans out the engine on hot restart. What happens if you set the switch to OFF?

One of the reasons Ford used the IAT2 sensor style they did was, the actual sensor's temperature sensing wire was essentially immersed, without protections, in the IAT2 air flows inside the manifold. The sensor's response times are stunningly fast and quickly could tell the ECU what is happening, so protective fueling strategies could be implemented if necessary. The Bosch 2.5 BAR pressure/temperature sensor uses the same 'naked wire in the air' approach. This 'exposed wire' approach minimizes the effects of heat soak on the sensor data after the engine has been shut off and then restarted in a short period of time. The data communication with the ECU is also at electrical speeds for the MAT and MAP portions of the sensor.

If you are using Ford's IAT2 sensor or the Bosch 2.5 BAR sensor, then all those words are interesting, but add nothing to the solution because you are already using the right sensor design. BTW in the FWIW category, both the Ford and Bosch style sensors are quite sensitive to overheated IAT2 temps. If you get temps much above, 200 ˚F, the sensor's plastic housing begins to soften, and sensor failure is imminent.

These little small displacement engines will slam your eyeballs wide open with just a little boost and the right amount of fuel — really impressive little monsters. :giggle:
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I was digging around in Tuner Studio and clicked a help button that brought up this EFI Analytics window on WUE. It looks like there is an Analyze Live capability to auto-tune this function.

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The screen I was in when I clicked to bring up the above window is below. Clicking on the blue question mark next to Extended Prediction gets the screen above.

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It might be interesting to see what analyze live says about ASE.
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I have no yet tried the suggestions, but I found something interesting in the datalog. This screenshot doesn't say much by itself but I'll explain.

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White line is MAT, red is AFR. When I started the engine, CLT was at 150, MAT at 135. You can ignore the red line for the first minute because I have the sensor on "slow heat", so they won't work for about the first minute the engine is started.
The MAT dropped to 120 in about 15 seconds, which was about the correct reading, un-heat soaked (if that's even a word). The lean condition stayed for about 75 seconds. My ASE is configured to be active for 276 engine cycle after start, which is 15 seconds at 1000rpms give or take. During this time, there is no MAT correction, but the lean condition exists. This leads me the believe it's not caused by the MAT sensor that was heat soaked but by something else.

Cold start are good so not sure if I should run WUE autotune again, since the feature is made for cold start and not hot start, where I have my lean condition.
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I don't have any insightful thoughts on this one, Michel. I would try DIY again. While they tend to be miserly with tech for the non-PnP systems, they do claim they will answer questions for PnP customers. The line might be a bit long, but their insights are probably better than the average bear, as Yogi used to say ...
I must have spent more than an hour analyzing datalog for every 5 minutes I've driven the car lately. I think I have found something interesting today.

I noticed my fuel pressure seems too low, sometime. When the car is dead cold, it's at the expected value. When the car is hot, it get about 10psi too low. I added a calculated field in MegaLog Viewer. The formula was 40 (base pressure) + Boost (negative value for vacuum) - Fuel pressure at the sensor. Normally, it should have been close to 0 all the time. But here's the graph
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Red is fuel pressure, you can see it's trending down.
White is MAP.
Green is the calculated field, it's trending up. After the 12 minutes ride, it was averaging 4psi too low. On the ride back home, another 10 minutes, it was averaging 10psi too low.

Having fuel pressure dropping for the same MAP, as the car runs can have an impact on why it's running lean on hot start, and may have messed up my Ve table.

What would be the cause of that? I know the vacuum is correct as I have plugged a gauge at the fuel pressure regulator when diagnosing my vacuum leak and it's fine. Also I get the correct pressure when it's cold. My fuel regulator is a Fore Precision Works F2 that I ordered in 2010. My best guess is that the diaphragm is dry and temperature affect it. I'm all ears on suggestions here, especially since I can't order a repair kit because the company doesn't exists anymore.

On a side note, I was thinking about the converting to returnless fuel system next Winter. Is that a good idea? If so, I may buy a cheaper regulator, or go to this project now instead of wasting money on a regulator I'll only use one year.
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A couple of thoughts in no particular order, Michel ...
  • Many of the Fore Precision items like filters and I suspect regulators (but don't know with certainty) are still serviced by Fore Innovations,
  • I have a personal preference for returnless systems,
  • Returnless systems typically use PID controls to manage fuel delivery,
  • This is an excellent TToC write-up on PID control (which 99.99% of the guys never read, let alone tried). Click here => PID Control. Definitely watch the NASA video on F8 Pilot-induced flight surface oscillations when they were attempting to transition to computer-controlled fly-by-wire controls. This same link can be found in the TToC in the Tuning Section. It is titled, Returnless System Hesitation II.
Those flight surface oscillations are the exact same problem the returnless fuel systems have with fuel pressure oscillations, when implemented without PID controls or when implemented with PID controls that have not been properly configured or worse entirely zeroed out so they are inoperative.

Returnless systems have a number of attractive attributes compared to return style, but you will need to manage the returnless system with PID controller logic. I recommend starting here => An Idiot's Guide to the PID Algorithm. It is a very good introductory guide to PID controllers, what their three components are, how they affect the controlled process, and how to go about using them to control the process you are working with.

BTW in fairness, you can also use the less sophisticated, but also effective, approach that Jerry at Sutton Performance describes in the PID Control link above.
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Plot twist, I don't have fuel pressure issue. The problem lies with the fuel pressure sensor. I used the fuel pump test to let the pump run and check the pressure at cold, when the engine ise not running. I had 41psi from the sensor and 38psi on the mechanical gauge. I then went for a 15 minutes ride. When I was back in the garage the sensor reported 26psi of fuel pressure with the engine stopped and the pumps on. The mechanical gauge reported 38psi, same as when the engine was cold.

Now the question, why does heat affect the sensor this much? There's also no way I can use that when I convert to returnless. Not a critical issue or show stopper for now, but it's something more in the TODO list.
Where's the sensor mounted?
I would verify that the sensor is good by either buying another one one or relocate that one to some place cooler.

Where's the sensor mounted?
I would verify that the sensor is good by either buying another one one or relocate that one to some place cooler.
It's on the fuel rail
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I bought two of these sensor, the other one is for oil pressure. My next step would be swapping them and see if the fuel pressure issue persist. It's hard to tell for the oil pressure since it is supposed to drop when warming up and I have no previous data to compare how much it should drop.
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I don't know if the returnless system would cause the pressure to fluctuate or not.. I'm here with a bag of popcorn waiting to see what you find out.

I haven't read through your thread so forgive me if my next question should be obvious but is the fuel pump new or in a known good working order?

Fuel pumps have a couple years but they have been tested and they are good. It's not a fuel pump issue. When I got back from the 15 minutes ride, I stopped the engine, went to test mode in TunerStudio and activated the fuel pumps. The fuel pressure seen by the MS3 was 25psi, and on the mechanical gauge was the same 38 than when it was cold. So clearly, fuel pressure, regulator, pumps are good. The culprit is the fuel pressure sensor.

Returnless would have been a nightmare with a faulty fuel pressure sensor, since that's what the computer would use to drive the fuel pump speed. My guess is my fuel pressure would have ended 15psi higher than it should have been.
I'm following you now. The ECU is reading off that sensor thus screwing with the tune.
I didn't see where the mechanical gauge was connected so I'm not sure if it's reading the pressure from the same port or some other port.

I would swap the oil sensor with the fuel sensor and see what happens.
If it does the same thing then:
1. The sensor could be reading accurately and pressure in the rails is going down even tho the mechanical guage is reading differently.

2. The heat is affecting the sensor causing it to read faulty.
2a) What you can do is remote mount the sensor by getting some 1/8" copper tubing from the hardware store (2ft-3ft?) and connect the tubing to the fuel rail where the sensor is now then move the sensor to the fender or some other place just temporary and test it.

Plot twist, I don't have fuel pressure issue. The problem lies with the fuel pressure sensor. I used the fuel pump test to let the pump run and check the pressure at cold, when the engine ise not running. I had 41psi from the sensor and 38psi on the mechanical gauge. I then went for a 15 minutes ride. When I was back in the garage the sensor reported 26psi of fuel pressure with the engine stopped and the pumps on. The mechanical gauge reported 38psi, same as when the engine was cold.

Now the question, why does heat affect the sensor this much? There's also no way I can use that when I convert to returnless. Not a critical issue or show stopper for now, but it's something more in the TODO list.
I suspect it may be a sensor at or near its end of life that is causing the drift, Michel. When/if you convert to returnless, you will end up using Ford's manifold-referenced differential pressure sensor (FRPS), so this will likely no longer be an issue. That said, I would still replace this sensor with a known good sensor.
I did some test today. First I let the pumps run with the engine off for 15 minutes while monitoring fuel pressure, to check if it's using it or the temperature that cause the drift. There was no change in reported fuel pressure so I assume it's temperature.

Then I swapped my fuel pressor sensors and oil pressure since they are the same. Here's the new graph after a short drive.

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The green line is now stable as it should. Second graph is oil pressure, I ended with -14.2psi whit the engine nearly stopped, very close to the delta I had for fuel pressure. In conclusion, I have a bad sensor. That's a bummer since I bought it 2 months ago, $100 badly invested.

Ed, is this the correct sensor? => More Information for MOTORCRAFT CM5258
I would have chose one that is not boost referenced, because the ECU will know what the MAP is and adjust fuel pressure accordingly.

This is what I use to mount the sensor
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-8AN with 1/8NPT for the sensor. The Motorcraft one doesn't seems to use threaded hole. Is there another adapter I could use?
Also, do you have the specs for the pins? Hopefully, it uses the same 5v, ground and signal than my current sensor.
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The Motorcraft sensor was designed to attach to the main fuel rail on an OEM sensor flange. You can make up an adapter and put a 1/8" pipe plug nipple on the back to screw into your fitting, space permitting. If the space is not available, you can remote the sensor with a short feed line.

Fore built a mounting flange onto their Terminator fuel rails for the sensor. Most everyone else did not. This is a pic of the FORE Innovations solution:
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As long as the sensor is close to the fuel rail with a short (2, 3, 4 inch) feed line, you should be OK. Remember, the Ford (FORD, not FORE) approach is designed to maintain a 39.15 psi delta pressure across the injector. You can do this with a manifold pressure referenced return-style system architecture and just set your base system pressure to 39.15 psi with a return line back to the tank — which you already have.

If you use a return-style architecture, you will not need to worry about PID programming or buying an FRPS.

p.s. I just found this on the Fore website, click here => Fuel Rail Sensor Remote Mount. This little gizmo will allow you to mount the FRPS directly to your pressure regulator instead of the fuel rail if you intend to use an FRPS.
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Ya know, I posted a link to the pressure XDCR's I use that are inexpensive which I have 5 or 6 installed on my car but don't see the post.. After some digging I found I replied to my own thread instead...duh...

If you haven't seen these sensors the price is right and I have five or six on my car and the cables are inexpensive too:

Welcome to the dance, Kevin. I've done that more than once :)
Kevin, your thread about the pressure sensor popped in the new post today and I was like "wow, why didn't I see that when I needed it"

Ed, what I'm doing is in two times. For now, I'm using a return-style fuel system, and the fuel pressure sensor is only used to datalog the fuel pressure, I'm not doing anything else with that. I'm not worrying about PID programming yet.
Later on, maybe next Winter, maybe never, I'm tinkering about the idea to convert to a returnless fuel system. Then, the fuel pressure sensor will be important because it will be used to adjust fuel pump(s) speed. The way I see it, I would need to change fuel rails and use the mounting adapter. The remote feed line could be a temporary solution so I can use the sensor right now, and install it properly when I do the conversion.
Also, I don't get why I would need to use a vacuum/boost reference. Since the MS3 will drive the pumps, it already know the MAP and should adjust so the sensor reads the correct pressure, right? That would save me some more vacuum tubing to manage under the hood, and remove some lag.
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... I don't get why I would need to use a vacuum/boost reference. Since the MS3 will drive the pumps, it already knows the MAP and should adjust so the sensor reads the correct pressure, right? That would save me some more vacuum tubing to manage under the hood, and remove some lag.
When you are reading a composite metric like delta pressure, I like as much of the sensor hardware to be integrated into a single device. It is more compact and potentially more responsive to change, and in the end, you only want the delta pressure, so I have a personal preference for the more integrated solution. That does not mean multi-component equivalents will not work.
Today was a beautiful day outside so I enjoyed a 30 minutes ride in the car. First time I have enough confidence in the tune to go WOT. I erred ridiculously on the safe side. Nevertheless, according to the datalog, I made 627hp, 666lbs-ft torque @ 5000 rpm with 18psi of boost. Timing was at 13* (very low) and 0.70 Lambda (stupidly rich), so I'm quite pleased with the numbers.
What scared me the most, is I had very loud backfire at 6000 rpms, like gun shots, just like the problem I had in October and made me swap to IGN4 coil and MS3 ECU. That was a real bummer and I went home quite sad thinking it was the valve spring after all, and that would be a big engine job that I don't have time for now. Then I had a flash. Yeah, that engine cutting out at 6000 rpms was the rev limiter.
It's coming along nicely, my Ve table is close enough, timing is very conservative for now.

About the previous issues:
- I still have small backfires around 2500 rpms that are driving me crazy because I have no idea why

- On the stalling issue, it's 100% because of MAT-retard. I just disabled it for now (that's also why I keep timing very low for now). There is no way to not remove timing base on MAT depending of the MAP. I even downloaded the source code of the MS3 firmware 1.4 and I've seen it myself. I went as far as adding the code and submitted it on the msextra forum, for version 1.6. Funny enough, MalcolmV8 was also in that thread asking for exactly this feature. Hopefully it will be done
ref: Feature Request - MAT based timing retard should also be based on TPS - Megasquirt Support Forum (MSEXTRA) and MS3 pre-1.6 alpha 2 firmware - Page 2 - Megasquirt Support Forum (MSEXTRA)

- My fuel pressure issue that I determined I had a bad sensor, well, now I have 2 bad sensors. The second one started doing the same thing. Must be something in their sensor that is not fully compatible with fuel. It's listed as compatible with gas but good luck to me to have it warrantied.

- The lean hot start issue is still happening. After my 30 minutes drive, I washed the car for about 45 minutes outside, and when I went to park it in the garage, it would run lean enough to stall in neutral. This is a widespread issue, Malcolm also commented on that on the msextra forum => [Feature Request] AFR Table based on CLT - Megasquirt Support Forum (MSEXTRA)
Long thread but worth reading. It seems to be something about fuel puddling and vaporization, my knowledge is limited on that subject.

The good news, and I hope I don't jinx it, is the issue I had about hitting a wall near 5500rpm in October, was indeed a problem with the coils and could be solved since I was able to rev cleanly to 6100rpm, right where the rev limiter was.

Next step will most likely be a day at the track to finish tuning the finals row in the Ve table (way too risky on the highway as I hit 100mph in second gear at 6000rpm).
Side note, something I learning in the process of building the Ve table. For the same load, Ve is very stable across the whole range. For the same rpm, Ve goes up quite fast with load. Knowing this accelerated the process a lot. When I was confident about my Ve at let say 2000 rpms, I could take that value, add 10% and applied that for the whole rpm range. Then autotune can finish fine tuning it, it's already not that far.
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