Megasquirt Considerations

[Guest incalescence]

I've lurked for a while, and as many of TonyD's posts insinuate, I'm very tired of trying to "tune" my 78z with turbo conversion using N/A components. I feel like everything is rigged and it's driving me nuts. It's almost bonus time at work, so I'm figuring if I put a little aside, and then take the bonus in a couple of months I might be able to go with Megasquirt.

 

My only reservations is that I've never tuned a standalone and don't feel much like blowing something up.

 

I've read through the megamanual a couple times now, and it sounds like once I am able to get it running/idling, I should be able to go after it with a wideband and go at it with the autotune functionality. Anyone tried this, and is this a good/bad idea? It looks like you should go at it slowly, but looks doable, just looking for real world experience.

 

I would be triggering ingition events from the N/A VR dizzy. The mechanical advance is already locked out, just need to take care of the vacuum advance. The engine itself is running pretty good, but I know its not running as good as it could be, and the flapper door needs to go. That's just not a suitable way to tune an engine.

 

In this instance, is it more advantageous to run MSII or MSnS on a V3 board? Any suggestions are HIGHLY appreciated? Been reading a bunch, but looking for that real-world information from people who've done it. It seems like so many posts jump from going to do it, to it's running. Didn't see a whole lot of posts on tuning theory, etc, nor a real layout of what's better than this or that.

 

Thanks!

[clint78z]

No step is that hard in Megasquirt system, there is so much help out ther for this system. I would say 60% of the heartache deals with how the wiring harness hooks up. Be very dillegent about proper grounding wires and were grounds are actually grounded. Soldering, heatshrinking, routing signal wires away from power wires, proper shielding signal wires. Make sure you have good clean connections !!! Follow all the setps in the manual, do not skip over.

 

Once you have it wired, simply ask for an MSQ from these guys and you should be very close to a wonderfully driving car. As far as tuning there is info here http://www.megamanual.com/v22manual/mtune.htm

 

Datalogging is your friend use it all the time. I would suggest the VE map be roughly tuned before enabling autotune, other wise it can just make a mess of things.

 

MSII extra has a more features and better resolution than MS1 extra, but it is limited by on to only 4 igntion drivers. For a your distributor you only need one.

[cygnusx1]

It's not as hard as it sounds. Setup a ground rail, and a hot rail. Connect all the grounds to the ground rail with a nice heavy ground to the battery and the same for the hot rail. Then you need two relays. Only one(main) of them ties into the key switch. The other (fuel pump relay) is all controlled by MS. The MS harness is very clearly labled and color coded. It all comes down to good wiring habits and understanding what you are doing. Tuning is easy once the car is running. Getting the car running was easy because my wiring was correct.

 

All the "things" are turned on and off by the two relays. You just wire them back to whatever relay you want to use to turn them on and off. Put fuses in each line.

 

Dont forget to setup the board to match your intended use (jumper wires and such). DIYAutotune and their site can help you. You need to setup the tuning software, Megatune, to match the hardware/firmware you are using. It's all pretty easy but I will admit it was overwhelming coming into it.

[datman]

Here si my recent experience.

F54 N/A P90 head/ 2mm head gasket. CR 8.35:1. MegasquirtII.EDIS. Holset HE351(HY35).

Like you I had never tried anything like this before. After fitting the engine back in the car and connecting the fuel system I connected the pump to 12v to set the base fuel pressure and check for any leaks.

I then connected all my ignition side of things and then played around with connections and VR sensor wiring until I had a solid spark when cranking.

At this point I wired the megasquirt and connected the injectors and fuel pump to a separate fuse block removed the fuses and loaded an msq filefrom the upload msq file thread. The 2 things that I was most concerened about were ignition settings and injector settings as I ad read stories about burnt out injectors and ignition drivers.

All the info is in the MS manual and hybridz has some great threads also.

I was lucky as my car started pretty much first time and only needed a small adjustment to the throtlle plate to idle.

Once the engine had warmed up enough for warm up enrichment to turn off and acceleration enrichment was set off I adjusted the required fuel setting until my AFR was near 14:1.

I should be able to start driving the car and logging runs this weekend with anyluck.

Good luck with your car!

[Guest incalescence]

This sounds very promising! I thank everyone for the inputs! Now to set the bones aside to buy the unit.

 

I've never - EVER - soldered a PCBoard. Best to get an assembled kit, or best to just pony up and put it together yourself?

[cygnusx1]

I bought it assembled...I am no electronics pro and my time was better spent reading the manual.

[Tony D]

It's not as hard as it sounds. Setup a ground rail, and a hot rail. Connect all the grounds to the ground rail with a nice heavy ground to the battery and the same for the hot rail.

 

Cygnus you S.O.B.! Why didn't you say that last June!

 

I have to agree that wiring is usually the biggest bugaboo that causes heartache on the systems!

 

We are running a 'much more expensive' ECU on our Bonneville Car, and have had a niggling problem that we KNOW is electrically related. Last month, before the ElMirage Meet, we did just as Cygnus suggested, and ran a ground and power rail. I found them at Orvac Electronics in Fullerton and they were $15 each, and another $6 for a nice red and black plastic cover to keep anything from dropping on them. I WISH I had known these were available so readily and nearby my house, I would have utilized them on my setup for sure. They are a marine product (for boats) and let you connect everything to a common bus where you know you have easy access to them for troubleshooting and inspection.

 

I don't have them on the MS system, but I do have two more conversions in the making, and I'm thinking this is the way I will go.

 

For the hassle of the DIY aspect of the circuit board, I might suggest getting one preassembled---it takes the guesswork out of it should you be questioning your technique or the box. For the cost over kit prices (what now, about $250 off E-Bay?) that works out to be about $50 an hour in my case (took me 5 hours for assembly)--given that I eventually had some cold solder joints found later on, that may have contributed to issues I was having...the preassembly may be a good idea.

 

I will say this about the tuning: Once you see the tuning, and get out on the road you can 'shift arrow up' and 'shift arrow down' while driving at steady state and realize just how the lean-rich adjustment affects how the car drives, you will have the low speed portion of the map done before you know it! May be richer than ideal (they usually are when doing it seat-of-the-pants) but it's not a big deal. What I found was that the interface on the $400 MS is very similar to units costing...er...a LOT more, and I find myself cursing the expensive unit for not having features that ARE found on the MS!

 

I've toyed with several Standalones now, and really, once you have a grasp of how one works, you will quickly pick up how the otehr systems work.

 

If you go into it with the following set of questions, and you can answer them for each component in the system, you will find it goes much easier:

 

1) What is it? (Nomenclature, what is it called?)

2) What does it do? (Function, what does this component do, and how? Does it switch power, does it open and close, etc)

3) What controls it? (and How---is it an electrical signal, pneumatic, thermo-electric)

4) What does it control? (and How---varies a current, changes a pressure, etc)

5) Where is it? What does it look like? (Component Location/ID-not really a big thing in such a small system, but knowing where you have to look for something or where to find it may help when you have a 'helper' trying to diagnose what it's doing while your eyes are watching something else.)

 

This is stolen from some Air Force Field Training---"Troubleshooting Through System Knowledge" before that point, the instructors were pretty haphazard about telling you how circuits functioned, or how equipment worked. They did a lot of rote memorization and parroting of technical manuals, but one instructor came out with this approach and it really helped me devour technical details about systems. If you can answer those 5 questions, you will start to realize how much many "Experts" really only have superficial knowledge of a specific system!

 

This will go hand in hand with 'Five Whys'---the old Japanese Management Axiom of asking someone "Why" five times to any given answer. If they can't answer "Why" five times before changing a procedure, then maybe they haven't thought out the procedure or system that thoroughly. It makes you think far beyond a superficial problem-solving mode, and get past what may seem to be obvious reasons to underlying root causes that may affect more than one system in the vehicle (or whatever!)

 

Good Luck, I digressed!

[naviathan]

I'm the exact opposite of cygnus. I built mine, but I'm good with electronics. Not so good at getting it running though apparently.

[Tony D]

Ya know, I thought the exact same thing naviathan...at least decently competent at soldering since I'd been through a NASA Certified Soldering Class like 20 years ago. how hard can it be, right? First unit worked pretty well till it went mysteriously DOA. Even Pete couldn't explain that one...

 

But the other two ended up getting sent to Pete who remedied a few items he found, and then tested them running his car with them. The key (IMO) if you make your own is to have someone else nearby where you can plug your box into his car and run it. If it runs, then you know it's nothing 'you did'.

 

Since I disregarded PRIMARY RULES set out by Moby, I was in a quandary where elimination through substitution was the only option. After Pete ran my boxes, I KNEW they were good. With an HOUR of getting one back in the car, I had a good fix on what really WAS the problem (Intermittent Heat-Related Failure with my 81 CAS) and within another 45 minutes I'd definately confirmed it and taken steps to remedy it.

 

Since finding the bad CAS (Rule #1 on Moby's Suggestions: Buy a car or donor with a RUNNING engine, so you know it works! Mine was a Takeout Junkyard Engine with components scrounged from two different sources) the car has been running fine.

 

If you have a place to test the box, you can put it together for yourself with basic skills, but having some place to test your boxes outside just a Megastimulator is a good thing to have available.

 

But I digress, Navi, are you sure it's not something in the box failing? (The Devil in me needs to feed a self-doubt in your soledering skills---LOL)

 

For someone who hasn't done anything before...and this really sounds bizzare, but I'd recommend buying both an assembled unit and a kit. You CAN get the components for about $60-80, with the board if you are dilligent in searching. Go through the motions of assembling one, while you have a good, known unit that you install. The procedure of assembling the box really helped me understand what the circuitry does. I may have baked this component or that, but when Pete told me what he had found---I at least knew where the components were, and what they were doing and could translate that to the problems I was having.

 

I may not have been able to diagnose it myself, but when it was explained to me, the explanation made sense!

[naviathan]

I both appreciate and understand your concern for my soldering skills, however I've assembled 4 (including this one) MS-II units and none of the others have had any issues. I've had customers email me with great results. They loaded the MSQ and ran with it immediately as configured, no problems at all. Not to mention I've been through this box a couple times thinking it was maybe this or that and found all circuits to be good. I've even replaced components not because they were bad, but because they were within the same circuit as one I had previously blown (VB921 and fuel pump NPN replaced with a 2N2222 never know when something right next to it is partial and only shows signs under load). I can look at the schematics for these circuits and I know exactly what they're doing. I'm a computer technician by trade and an electronics and automotive hobbyist by choice. My job keeps me proficient in my soldering and circuitry skils quite well. I'm Johnny on the spot at work, constantly making quick fixes to get the customer moving again until a more permanent solution can be handled. It's what I do so I know my work is solid. I'm still leaning more towards my valves being out of adjustment. It was fairly difficult trying to get the right settings on a new cam with new lash pads and rockers and assembly grease on it all. On that note, are the cam lobes suppose to be unfinished? I would have expected a nice smooth finish to the lobes, however the finish was rough and grey, not smooth and shiny. My machinist said that was so the new lash pads and the cam lobes could wear into each other for a matched finish. I'm not so sure.

[mobythevan]

Rule #1 on Moby's Suggestions: Buy a car or donor with a RUNNING engine, so you know it works!

 

Its nice when that is possible, I know a lot of people don't have the option to get there engine running or see it running before the Megasquirt install.

 

I just installed the bad LS1 and had to pull it right back out, not fun.