The XJ (Microsquirt) EFI discussion thread

At least 5 members have fitted or are currently fitting EFI, and a few are thinking of doing it.

Some of the members build threads seem to be filling with general Q&A, so maybe its time for a generic EFI thread for general discussion.

As far as I am aware only SQLGuy and Gennro are the only members with systems up and running, but how about a hands up for any members that have started a project.

To get the ball rolling;

No coil drivers in the ECU means you need an external transistor/igniter/module to switch the coils. In my case I will use coils that incorporate the switching transistor.

Switching the coils on and off is electrically very noisy, and having that switching away from the ECU simplifies many things, although it adds extra components.

Mircosquirt is constantly improving, and the new case is supposedly much more weatherproof than the older one. Wait for the new one would be my advice.

While waiting for it to come out, read up on the www.megamanual.com site and the other mega/microsquirt forums.

 

Ok thanks for this advice. But in your case u said will be using coils that incorporate switching transistor? which ones are those and which ones would be the best choice due size weight and amps draw?
Thanks for ur help I really appreciate I am really dumb about EFI except for the basic concept.

 

I have seen this in sql's Sig. Ive been curious.

Pros, cons?

 

Will 2006/07 Suzuki GSXR600 TB's also work as the 2003's?? Cant find 2003 TB's on a good price on ebay (they all above 120)but 2006/07 are around 60 bucks.

 

I'm using the on-board VB921's on my Microsquirt to drive Saturn (GM) SC coils from a junk yard. Pretty happy with that.

For built-in igniters, a number of Mega and Microsquirt people had reported good results with the Mazda Miata coils (called an MX-5 in other markets).

 

By the way, you will need a 36-1 wheel or similar. If you have a welder and an angle grinder (a mini-lathe is helpful too), that will make it a lot easier to fab one to replace the original reluctor.

 

Cons:

1. All the time and work that went into getting it running well (it does run quite nicely now)

2. It's trickier to remove the tank, because I have yet to chase down any suitable quick disconnects for the two fuel lines (high pressure feed from in-tank pump, and low pressure return line), plus there's the extra wire for the fuel pump. On the other hand, I rarely need to remove the tank anymore.

3. Extra current draw from the fuel pump, oxygen sensor, idle stabilizer, injectors, and (a very small contributor) the ECU. However, converting turn signals, tail light, and indicator lamps to LED made up for a lot of this additional load, and the Seca alternator seems well up to the load.

Pros:

1. No finnicky Hitachi carbs to pull off, push on, synch, clean, replace hard to find parts in, etc.

2. Whether the bike's been sitting 10 minutes or a month, push the starter button for a couple of seconds and it starts. Hot or cold (even REALLY cold).

3. Automatic mixture correction across the 7000+ foot (2000+ meter) elevation changes available within a couple hours' riding distance of my house

4. (Because I used a Ford throttle body, a Ford IAC, and built a custom intake manifold) No choke, no manual idle adjustment called "choke", and no any other manual intervention needed to maintain correct idle hot or cold.

5. Because I no-longer have the stock coils, I have driven this thing through SOAKING rain, and also after having pressure washed the engine, with no problems whatsoever.

6. IMO, pretty good fuel economy and good power and torque throughout

7. A programmable rev limiter (just in case)

 

Thanks SQL. But I was looking for something a little simpler since i dont have this many tools nor ur skills to make all that lol.

 

There is nothing at this point in time available that is simpler. You could keep the standard ignition and run the Microsquirt for the fuel injectors, but it would still be a custom system.

Realistically if you want to put EFI on an XJ you will need;

Approx $1,000 for trigger wheel, ECU, throttle bodies, fuel pump, relays, wiring, oxygen sensor (optional) and coils/leads.

An active approach to learning EFI basics. www.megamanual.com is a good starting point.

Some fabrication skills are also required. The more you can do yourself, the cheaper it is.

 

I read the manual e most of it is gibbrish to me i think I will have to postpone this project till they create NZT (Limitless movie drug) than i will get one pill only to build this lol.

 

Dark u mistook simpler by cheaper i am looking for something i can understand not really worry much about price.
1 grand its cheap compared to carb kit almost every year to clean up just the bottom if u need anything else on top of the carbs its extra 200 to 300 and if u lose any diaphragm than u looking for about same price as the whole EFI. Plus EFI will be synched forever and better fuel mileage and less carbon foot print.
The problem is despite i dont think its expensive I think its too much rocket science to me to assemble it and I fly B747 and thought those were complicated lol.

 

Because I will be keeping the standard crank pick ups, all the generic Ebay units are the wrong diameter. I have a guy on our local forum who does laser cutting and will be getting a trigger wheel made up an exact fit to allow retaining of both factory pickups (for redundancy).

Anyone else interested?

I didn't misunderstand, I was giving a rounded answer that may be of interest to other viewers of the thread.

 

How much that trigger wheel gonna cost u Dark?

 

I didnt read anything on manual saying u can keep ur original trigger wheel. I just read about keeping ur own coil but its not recommended because EMI.

 

What about this site with several sizes of trigger wheels?

http://www.trigger-wheels.com/store/con ... uk/d5.html

It might be cheaper for u Dark to buy from them and open a whole in the middle instead of asking to manufacture a new one from scratch.

 

There are eBay trigger wheels that will work (3" 36-1 wheels), like this one: http://www.ebay.com/itm/Universal-3-tri ... 3363d98c43

The reason I removed the second pickup was because it seemed to be inducing noise and false triggers into the line of the other pickup. YMMV.

Keeping your original coils, reluctor, and TCI is an option, but the down sides there are that you then don't have a good place to mount the MicroSquirt, and you lose the benefits of better ignition control (load-based retard, altitude-based advance, etc). The 36-1 wheel also makes it possible to do things like semi-sequential injection (synchronized to the crank) rather than just batch firing in time with ignition.

 

$20 to $30 A lot of us on the local perth bike website think nothing of helping others from the forum out.

 

I never thought to consider noise from the second coil. I wonder if twisting the leads to each pick up would make it less prone to noise.

 

Thought I'd post a few pictures of the current setup. This is the second manifold and third fuel rail that I used for this project.

Originally I used a stock Hyundai Accent fuel rail, but it was too long and stuck out the sides; the injectors also didn't line up quite perfectly with the ports, though they were very close.

The second configuration used a custom fuel rail with the first manifold that I'd made. The first manifold had a fair bit of difference in both straightness and length between the inner pair and outer pair of tubes; and it used the stock carb holders to attach to the head, which meant that the injectors were relatively far from the intake valve.

In the third gen, I built a new manifold to bolt directly to the head and to try to even out the pipe lengths and make them as straight as possible; I also made another new fuel rail that allowed the injectors to be centered on the ports and aimed (as much as possible) towards the intake valves. I made a number of other tuning and firmware changes during this time as well, but I still feel that this layout made for some good improvements in mid-band torque and idle smoothness.

Cheers,
Paul

 

pardon my ignorance but could something like thisbe used ?
once their off the rack the spacing would be solved, a fuel rail could be made up

 

yes BUT how are you going to fish them out and separate them so you can twist each pair individually? May as well just remove the one as it's the same or less effort.

 

They'd probably work, but a set of throttle bodies off of a modern 4-cylinder transverse FI bike would be easier and cheaper. I think I've heard that the GSXR 600 throttle bodies will fit, and sets can usually be bought reasonably on eBay with injectors included.

For instance, here's a set with injectors and fuel rail for $75: http://cgi.ebay.com/ebaymotors/2006-06- ... 3a6a6cd009

The one thing I couldn't figure out how to do with those types of setups is idle control. I wanted a solution where I would always have correct idle and could start the engine under any circumstances without having to crack or hold the throttle or use a "choke." Some factory FI bikes use a "choke" (that's what it says on the lever) to open the butterflies a bit extra when the bike is cold. I think some of the ITB systems use an ECU controlled solenoid for the same purpose.

Long story short, it may have been easier to convert to FI if I'd used a set of ITB's off an FI bike, and it probably would have resulted in some extra power at higher RPM's that I may be missing now (not that I think the bike is at all underpowered), but it would probably have been a lot harder to get the type of idle control I wanted (and now have). Also, OTOH, the larger air space in my current manifold may make for some better low-end power than I would have seen with ITB's.....

 

The pickups have their own harness, so I would just cut the plug off and remove the outer insulation. 5 minute job. The plug would be replaced with a sealed connector as part of the job anyway.

 

On mine, yes, they had their own wire bundle, separate from the main harness, but they shared a single ground wire back to the TCI; so making twisted pairs for them would actually have required replacing the wiring so that each pickup had its own ground wire.

 

I am currently working out an advance table for my system, and have already learned a few things.

To duplicate the factory advance curve seems very simple, as the XJ750 has a straight forward method of advance. Timing starts at 10 degrees and advances with RPM to a maximum of 36 degrees at 5,500 RPM according to the manual.

However the Microsquirt will have a MAP sensor, which now allows me to program for different amounts of load. Research finds an XJ1100 that uses vacuum advance as well as the RPM. The XJ1100 shows no difference in advance at high load (wide open throttle), but a lot more advance between 1,000 - 3,500 RPM at light throttle. With the full load advance being almost identical to the 750, this is changes I am happy to use as a guideline for making an advance map.

I would expect better low speed low load throttle response with this addition to the bike.

Research, learning and then application... fun times

 

I suspected there were only three wires for the two pickups but was too lazy to look at my wiring diagram

 

How do you add a return hose back to the tank for the regulator?

 

I used 1/4" copper plate and brass plumbing barb fittings to make fittings for the tank.

On the left side I made an oval base plate and soldered half a barb fitting into it to make a tap that mounted in place of the original fuel cock.

On the right side I soldered together a brass barb with an NPT threaded end with another half of a barb fitting to make a panel mount double barb. I then used another piece of copper plate and an NPT tap to make a nut for the fitting. I attached the inner part of the double barb to the in-tank fuel pump's outlet, and fed the other end of the barb out a new hole I drilled in the right side of the tank. I then used a washer, some fuel-proof gasket paste, and the copper nut to fasten the fitting in place.

By the way, some systems use a regulator in the pump to provide reasonable pressures at the injectors without a return line. What I don't know is how these systems ensure correct fuel delivery when the rail pressure to manifold pressure is not a constant difference. I would guess that Megasquirt allows some option to adjust the injector pulse width based on the instant MAP reading, but I have never seen (nor really looked for) this setting.

 

Wow this is really interesting stuff, thanks for starting the thread and thanks also for the links.

I've done some reading and have a lot more to do, this is really grabbing my attention!

SQLGuy, you mentioned throttle bodies/injectors off a GSXR...dumb question here but would they need to come from a comparably sized engine? Such as from a 600cc to a XJ650?

 

Pretty much. The main factors are diameter of the throttle bodies, and spacing (if they're not separable/adjustable). Typically throttle body OD is going to be pretty similar to carburetor OD on similar sized engines.

If you're doing more fab work, like in the area of the pieces that mount the throttle bodies to the head, then you can get away with more mismatch in the diameter. I would still expect the best results to be from arrangements that provide a close match in ID of the throttle body to ID of the intake port.

 

Okay I see...I may have to start looking for a crappy (cheap) bike and start playing with this. Thanks much!

 

Just re-posting this from your original thread.

Also I had found a GSXR 600 rail that would work find off only 2mm.

Just an FYI to this thread, the Micro Module is available but with the 50 pin header to wire in and alternative comm and JP2 to wire in if used, is a lot of soldering and work. Plus you should have some experience with this kind of thing. Reading as much with the micro tune system is a huge plus to know before hand. Read as much about this system will help you with other EFI systems which are all basically the same running off the typical lm1949 microprocessors. I didn't spend more than $700 for pump, regulator, injectors (only running two independently), WBO2, Micro module, MAP, GM IAT, TPS and a Buell MAF. I also played around with the GSXR Hi-Z injectors that I got at a local salvage for $30. each.
I used the existing ignition pick up and trigger which works fine. You can utilize the wasted spark method quite easily. Isolation from RF noise is a must and there is many methods you can find on line to reduce from particularly the coils. I even used copper tubing, grounded, to run wires through.
Alternatively there are many simplified circuits available that can be built that are called Alpha N controlled. Meaning TPS and O2 are the main control factors and runs in basically an open loop mode. Most early EFI systems were this way. Once your read more about this stuff you'll realize a good working system can be built between $500 to $1000. Depends on where you find sensors, your capability to build hard components, understand electronics and have experience assembling basic circuits involving micro processors. Some have made Alpha N using the Arduino processors.
Learning this stuff may seem daunting but like anything else, once you start to understand the basics the rest is easier to learn.
I've posted in here I have a home turbo mod on my little 550 and used the miro squirt module.
Excellent job on the 750 btw. Nice work.

 

The Mega/Micro squirt systems all use Motorola processors. MC9S12C64, in the case of Microsquirt.

I'm surprised that your project turned out quite that cheaply. My best guess on parts runs like this:

Microsquirt 400
Bosch Pump (new) 90
Copper and brass pipe fittings for manifold, fuel rail, and fuel connections 150
Fuel line 15
Injectors (used) and injector cleaning 110
Throttle body with ISV and TPS (used) 10
Coils (used) 15
Plug wire caps 30
IAT (used) 2
Fuel-proof paint for manifold and fuel rail 8
Throttle cable 12
36-1 wheel (materials) 30
1/4" copper plate (materials) 30
Relays 10
Fuses, wire, electrical tape, and electrical terminals 30
Head temperature sensor (new) 15
Innovate LC-1 WBO2 with gauge 160
Screws, nuts, bolts 25
Air inlet hose 5
Metal plate for rebuild of air box 5
Silicone RTV 8
NCV1124 and other mod parts for Microsquirt VR conditioner circuit 10
Silver solder for manifold and fuel rails 20
Gasket sheeting 5


For a total of $1195, not including shipping, special tools, and things I already had on hand (like the 7mm copper core wire for the new ignition wires). This is all based on the stuff currently on the bike, not the stuff I decided to change after having done it once (or twice) differently before. Hmm... also forget hose clamps and the fuel filter...

OTOH, I did recoup some credit for other XJ parts I needed by trading in my old carbs and TCI.

 

The module I paid for (at the time) was only $250. I'm pretty familier with the MC9S12C64.
The module at that price, did not come with the housing at all or Harness. I made all that. Keep in mind I have a bunch of parts, wire, mill and layth. Basically to include time and energy and parts paid for months or years ago, yea you're right, still probably around a grand or maybe more. Yet out of recent pocket as of this build (only the EFI part) was actually 686.37 including incidental purchases. The filter was given to me, I've had pipe laying around for years in the diameter I needed, etc. The bike modification hard costs itself, was WAY more. If you haven't already you can see the project here.
So are you done with it now? Are you driving it around? Have you put some good miles on it yet?

 

Oh, I've been riding mine for about three years now. The last incarnation (second gen intake and third gen fuel rail) has been in place for about a year. I'd guess I've put about 4000 miles on the bike since converting to Microsquirt.

 

What difference in your mileage did you find, now that you've had some real decent mileage put on it.

 

Can't say, as I never had any good measurement "before".

After, on long trips up in the mountains (a lot of up, and a lot of down, mostly 55MPH+, and between 6000 and 11000 feet elevation), I got between 52 and 56 MPG on three different 150 mile plus trips.

 

Just a heads up and anyone shopping probably knows this.
There is a NEW version of the microsquirt coming out very soon. Inventory is pretty much gone of the old ones I guess so if you tried to buy one you probably couldn't.

The new version is in a much more waterproof case and has some software as well as hardware improvements.
Big difference is they took the coil igniters out of the microsquirt so you either need coils with that function built in or a separate igniter (driver) whatever you wanna call it.
This was mentioned in the first post on this thread and that is for sure the case.

GOOD news>>>The price is going down!
I read in a couple spots it's gonna be $299 for the controller!

I HOPE to start my conversion project this fall but plan on building a small stand to be able to tune and tweak the engine outside of the bike frame and a buddy has an engine dyno so I hope I can simply take it up to him and slap it on the dyno for fine tuning before I even put it in the bike.

 

My 700 got about 45mpg originally. After the 2 carb conversion it dropped to 42 mpg but runs exceptionally well. 52 to 56 mpg is great. Now a fair ballpark figure, how much does it cost to do this conversion?

 

I think it's still gonna be between $750-$1000 depending how creative you get and how lucky you get on Ebay plus your own fabrication abilities.

I would LOVE to strip my carbs and put injectors in there but that's just too damn much work for me. It would be nice to maintain the stock OEM look but have the performance of EFI....but maybe the 2nd time?

I'm planning on buying a throttle body set-up off a EFI bike and adapting that. It will have the TPS, injectors, fuel rail and SHOULD make the conversion a lot easier than SQLGuy project. I THINK the new configuration will make the low end tuning much easier.
He did his a while ago (a pioneer and I hope that there is more stuff available at better pricing than back then.

 

So I have two XJ700s. I'm going to go the Genro route and use GSXR Throttle bodies.

Since I have one XJ running just fine, I'm going to pull the engine out of the other bike, clean the frame up, and rewire everything. Genro pointed out the need to isolate certain wires from the rest with foil. Is there anything in the bike's (not including the Microsquirt harness) that I should sleeve before I button it all up?

Then what on the Microsquirt should I sleeve? (I'm using EMI/RF braided sleeving to make it all pretty... and sturdy.)

 

Leave the standard wiring on the bike as is.

The circuits prone to interference will be your crank triggers and low level ignition outputs. These circuits are the lowest level and most prone to being effected by noise.

Your typical car will have these shielded as well as the oxygen sensor.

By memory there is a lot of reading on the mega/microsquirt site that details most of this.

 

I'd love to see this offered as a kit to buy hint hint Len

 

I'm not rewiring for the sake of the EFI. I'm rewiring because the wires have been chewed thru and parts canibalized for another bike before I bought it.

I build a lot of wiring harnesses for man portable systems, so wiring won't be an issue. I think I can probably make it a little nicer than Yamaha ever did.

Thanks for the input.

 

What's going on with this little lot, anyone still running/carrying out EFI conversions?

Not exactly planning to do this myself at the moment (not enough cash & I like carbs anyway!) but I find this a fascinating subject all the same, and could maybe be tempted to fuel inject an engine one day in the future...

 

My project is not dead yet.

I have been busy sorting out my junk and recreating a work area.

Finally cleared my backlog of repair promises and have a clear slate.

Just have to get my ass into gear.

 

Cool, will keep an eye out for it Isn't it weird though, that I necro'ed this thread the other day & suddenly skylark makes the first 'squirt related post for years in the mods forum the very next day! 8O lol

 

I noticed that most people who choose ITBs seem to be using the 01-03 gsxr 600 throttle bodies. Does anyone know if the later model ones have the same od, or would otherwise be an improper fit?

 

From memory the gsxr throttle bodies only fit the spacing for a 700, not a 750.

Certainly they were not a plug and play option for my 750 seca.

 

Well that's good to know. What throttle bodies did you end up going with on your 750?