84 CJ Truck Build (Project Do-Over)

[a_kelley]

Though really, sequential really only plays in to any great difference at idle.. above idle a the injector time is almost long enough to not make any power difference.

 

[a_kelley]

Yeah you got the concept of how that would work. If you have two extra outputs you can drop one active component. Crap, just noticed the input to the lower bjt should come off the uc output.

 

[Scooter402]

Though really, sequential really only plays in to any great difference at idle.. above idle a the injector time is almost long enough to not make any power difference.

True. Injector PW is really only a few ms, so I can see that off idle it really doesn't add up much. I could only ever get this engine to idle smoothly at about 8-900 rpm on a carb, but I'm sure I can drive that down a hair lower once it's EFI. But since I don't really see it spending too much time right on idle, it may not make a huge difference, especially for any power gains.

Yeah you got the concept of how that would work. If you have two extra outputs you can drop one active component.

That's awesome...Just for curiosity's sake (and to test my electronics abilities) I might have to at least draw the concept, if not try and make it work. But, I would likely just make the board run "as-is" just so I get the feel for what I'm doing.

Crap, just noticed the input to the lower bjt should come off the uc output.

That makes more sense now for the switching. Thought for a minute I needed to go dig out my electronics textbook again. Thanks for the input! It'll definitely get my mind working.

 

[a_kelley]

I recommend going with FETs if your going to do it.. less heat dissipation needed due to low RDS on & less voltage drop which affects PW also.. inj timing varies with battery voltage. The software should let you input inj latency values..

 

[Scooter402]

I recommend going with FETs if your going to do it.. less heat dissipation needed due to low RDS on & less voltage drop which affects PW also.. inj timing varies with battery voltage. The software should let you input inj latency values..

Seriously just learned about 4 things in that one statement... I need to read your threads more often. I've seen a few things in the software about injector characteristics, but I haven't gotten too deep into it as of yet. I figured I'd get it all together, design and build a bench tester, and then tinker with it for a while before I actually build the harness and install. Don't worry, I just might be coming to tug on your shirt sleeve a few times once I get going!

 

[Scooter402]

Not much to see here today. Got a new tube of RTV and a set of intake gaskets and stuck the intake back on. I forgot how frickin' nasty that engine compartment is.

After I was done, I wrapped the top end in plastic to keep crap out of the throttle body and rails. I still need to put new o-rings on the injectors and add the retainer clips. And find those damn bolts so I can put my block off plates on the throttle body. But, baby steps are better than no steps, right?

Dug through my Photobucket and found a pic of the TPI setup I had on my old 383. Damn, I miss that thing. Couldn't wind out much past 5500 rpm or so, but god damn did it have some torque. It would lift the front tires from a stop. 40s, I might add. I busted a rear driveshaft more than once playing the "hey y'all, watch this!" game.

Just realized I still have the same valve covers on this engine that were on the 383... but the wrinkle finish is gone.

Anyway, back to our regularly scheduled programming.

 

[Croatan_Kid]

If you'll notice, that picture was taken at the hobby shop too!

 

[Scooter402]

If you'll notice, that picture was taken at the hobby shop too!

I should have just bought that bay. Hell, I rented it enough to have paid for it!

 

[Scooter402]

Started working on stuffing the PCB last night.

Most the resistors in...

Pins bent on the back side waiting to be soldered.

All soldered and clipped the ends.

All resistors finished being installed.

All capacitors and clamp installed. Be sure to note the polarity of the caps (for those that it does matter).

All diodes and LEDs installed. Of course, taking care to note polarity of these as well. The Speeduino guys made it easy and had polarity marks printed on the board.

Still have IC's to install, as well as the header pins to mount the microprocessor. And the MAP sensor there on the bottom left corner. Then I'll need to assemble my VR conditioner. That little biatch gonna be fun...

 

[Scooter402]

So this is cool...

The board is fully assembled, but not yet tested. You can see the com ports for the Arduino hanging out there from under the main PCB. The eleven billion solder points around the center there are for the header pins that connect it/communicate with the rest of the PCB. Now I need to assemble my VR conditioner, and design a bench tester and order some more junk from Mouser Electronics so I can make sure this pile o' parts will actually function. Stay tuned! (pun intended? Lol...)

 

[XJsavage]

If there was a trophy for enginuity, you'd own that shit. Badass! I wish I had the skill to do that.

 

[Scooter402]

If there was a trophy for enginuity, you'd own that shit. Badass! I wish I had the skill to do that.

Thanks! I never knew I loved tinkering with electronics until sometime relatively recently. But I'm most certain you could do things like this with your eyes closed. Like I keep saying - I wish I had your skill and imagination with all things metal!

 

[XJsavage]

Thanks! I never knew I loved tinkering with electronics until sometime relatively recently. But I'm most certain you could do things like this with your eyes closed. Like I keep saying - I wish I had your skill and imagination with all things metal!

Never know, we might even team up and build a buggy one day.

 

[Scooter402]

Never know, we might even team up and build a buggy one day.

That would be the shit!

 

[jcramsey]

@Scooter402 how’s the speeduino stuff compare to mega squirt? Apples to apples or totally different capabilities/intent/required skill set. I could use the google...but I figure you’ve already done the heavy lifting and could fill me in

I wanna turbo my inline 250 one of these days... efi would be a nice complement.

Keep up the good work!

 

[Scooter402]

@Scooter402 how’s the speeduino stuff compare to mega squirt? Apples to apples or totally different capabilities/intent/required skill set. I could use the google...but I figure you’ve already done the heavy lifting and could fill me in

I wanna turbo my inline 250 one of these days... efi would be a nice complement.

Keep up the good work!

Thanks! And thanks for reading. I have in fact done a TON of research on EFI setups, as well as had a couple....none that I have been able to tune on my own, nor anything anywhere near as extensive as this.

In terms of Speeduino vs. MegaSquirt, this kit seems to be comparable on a fairly extensive level (according to what research I have done) to the MegaSquirt 2 kit. Has more capability than the 1, and not quite up to the MegaSquirt 3. It does have more capability than the MegaSquirt 2. MS2 has two injector channels, where Speeduino has 4. MS2 has one ignition channel, where Speeduino has 4. The MS3 kit can run full sequential EFI (for those wanting to keep sequential on LSx, for example), where the Speeduino kit can run a semi-sequential with the 4 channels. On the Speeduino kit, you can have full ignition control (dwell, spark advance, etc.) and control 4 coils (or 8 with a wasted spark). The engine management software is incredibly user friendly and is pretty self-explanatory when tuning the fuel/spark tables (so long as you read through EVERYTHING). The fuel tables (VE and AFR) are 16x16 resolution, so they are plenty big. I'm pretty sure the timing table is the same. I'll update if I find differently next time I'm on the Tuner Studio. You can put more resolution in the bins in the areas where you'd like more fine tuning, and rely on the computer to do the rest via linear interpolation between bins. There is a 2.5 bar MAP sensor, so you can run boost readily with Speeduino (as well as the MS kits). I don't think there is an integrated boost controller, but the kit does have a rather extensive prototyping area for the tinkerers of the world. So if you were so inclined, you could probably create your own. If I were running boost, I'd probably just do it old school, since I'm not a drag racer needing to make changes between passes.

The cost of the Speeduino kit has thus far been less than half of that of the MS2. Some of that is probably because the Speeduino kit is a little more DIY than the MS series. Speeduino hasn't created their own line of bench tester like the MS guys, nor do they sell a universal harness or enclosure...those things you'd have to come up with on your own. I'm not afraid of grunt work, so I chose to go Speeduino - ESPECIALLY for the cost. For the PCB, VR conditioner (which I'm using since I'll use the magnetic pickup in the distributor for tach signal), the Arduino microprocessor, and all the components to populate the board, I'm right at about $120 invested at the moment.

In terms of required skill - if you are purchasing a kit to assemble yourself, it's really a direct comparison in terms of electronics knowledge/assembly.

Cliff's Notes version for those that made it this far - in terms of capabilities, the Speeduino kit is between MS2 and MS3. Intent is exactly the same - fuel and spark/timing control totally tunable via laptop or Android (either with a USB cable or Bluetooth adapter). Required skill for electronics assembly I think would be moderately skilled...no need to be expert level by any means. Basic understanding of electronic circuits and practical applications of Ohm's Law (and Kirchhoff's Laws as well) help if you intend to create your own bench tester, and some basic automotive wiring skill for the harness.

I'm picking away at a bench tester as I have time. Once I get a circuit drawing created, maybe I'll post that up for anyone that might want to build one of these too.

 

[Tim C]

Definitely post up the bench tester when you get it done. I'm toying with the idea of putting efi on my fairlane when I get my new motor together. I've been looking at a Microsquirt but I'm going to look into this stuff harder now that I've been following along here.

I've played with a ms3 pro evo system we put on a buddy's BMW, a TPI setup on my dads 67 c10, and I've tuned my own maf equipped Chevy tbi setup on my Ford rockcrawler.

The fairlane I was just figuring batch fire and timing but letting the dist handle the firing order. So the micro would work for me but this looks interesting. I'm loving it so far.

Sent from my HTC6545LVW using Tapatalk

 

[Scooter402]

Definitely post up the bench tester when you get it done. I'm toying with the idea of putting efi on my fairlane when I get my new motor together. I've been looking at a Microsquirt but I'm going to look into this stuff harder now that I've been following along here.

I've played with a ms3 pro evo system we put on a buddy's BMW, a TPI setup on my dads 67 c10, and I've tuned my own maf equipped Chevy tbi setup on my Ford rockcrawler.

The fairlane I was just figuring batch fire and timing but letting the dist handle the firing order. So the micro would work for me but this looks interesting. I'm loving it so far.

Sent from my HTC6545LVW using Tapatalk

I'll definitely post it up if it's going to help you and/or anyone else. The Microsquirt would definitely do what you need, but this kit would be much cheaper (I'm pretty sure of it, anyway). Much more fun, too, if you are into electronics assembly. Depending on what kind of injection setup you use, you'd have to split your injectors between the 4 drivers, unless you went TBI with only 2 injectors. I'm assuming you'd have at least 4 with TBI, unless you went with an MPFI setup similar to mine. The only difference between this semi-sequential setup and batch fire is having to take a little more care with the initial wiring so you get the injectors wired to the correct drivers...after that, the ECM does all the rest. I'll try and make some decently detailed posts once I get to the wiring and setup portion of this project.

 

[Scooter402]

Finally got done with fooling around with a sketch for my bench tester. It's been busy lately, so I haven't had much time for it. But now that I have the circuitry all sorted out, I can get a little bit more junk and put this together too.

So it's pretty simple...another sad aspect of why it took me so long. Actually took only about 10 minutes to sketch once I found the time...the longest part was writing down all the math to show my work for the curious minds out there.

Here's the diagram, showing where things are to be terminated on the PCB. This will be powered up with a 9V battery.

I'm going to use a 555 timer in astable mode to create the required square wave signal for the RPM input. The rest are just potentiometer circuits to be able to see how the ECM reacts to change in throttle position, AFR, coolant and air temp. There is one voltage divider to drop the 9V signal down to 5V so I limit the pots to the max 5V Vcc typically provided by the ECM. The reason I chose the 4.7k resistor in the divider is that I had a couple extra... the other resistor in that circuit worked out by the math. The pile of 1k resistors is to limit the current to the pots, because they can only handle 50 mW power.

A little light math for the curious minds... pardon my messy chicken scratch!

Since HEI distributors in a V8 application have 4 spark pulses per revolution, I could convert engine speed to electrical pulse frequency to determine the components needed to get the correct range sweep from the square wave signal out of the timer circuit. You can obviously convert any ignition signal to spark frequency, but for anyone else needing to know about HEI...well, there you go.

Sometime in the near future, I'll order these things that I'll need and some prototype board from Arrow electronics (free shipping from them!) and put this together.

EDIT:

Oh, and I was doing some reading on the Speeduino documents on the interwebs… @jcramsey, you might be interested to know that this kit actually does do boost control. You can add the boost control solenoid to the wastegate and you be in bid-ness! Gets me thinking...hmm....

 

[Scooter402]

Another tiny update... quite literally

I assembled my variable reluctance conditioner today. I believe I explained its function earlier, but it takes the sine wave signal that is generated by the magnetic pickup in the distributor and makes it a 0-5V square wave for the microprocessor to properly read the RPM signal.

Ain't it cute? Those little surface mount capacitors and resistors weren't too bad.

But that MAX9926 was a bitch. Close-up shot under a microscope to show that it actually is soldered instead of a just-pretend pic.

Those pins are on a 0.5mm spacing...that's a hair under 0.020" for the 'merica system.

I'll still need to put in the header pins so I can mount it to the PCB. Baby steps!

 

[a_kelley]

What method did you use to solder the tssop?

 

[Scooter402]

What method did you use to solder the tssop?

Since I'm a glutton for punishment...I must have been a masochist in some former life. I actually hand soldered it with a fine tip in the iron and 0.5mm wire. I thought I might appreciate doing it that way at least once. Of course, I had to use plenty of flux and a solder wick to take care of a few bridged pins.

If I had to do it again, I'd definitely use solder paste and the oven. We have both in the electronics lab at work (where I also borrowed the microscope to inspect it once I was done), and I probably would have saved major headache had I done it that way from the start... but I wanted to try to do it by hand once just to see if I could. Would have sucked a little if I screwed it up though!

 

[a_kelley]

Drag and wick method works pretty well. (Larger iron and flood and wick)

 

[Scooter402]

Drag and wick method works pretty well. (Larger iron and flood and wick)

You're the second one I've heard say that! After I got done fighting with this thing, one of the EE's here said it's actually easier with a little bit larger iron. This was me: "oh, now you tell me!" Live and learn, right? I've worked with some SMD/SMT before, but this was a first for me with TSSOP. I'll admit....I was kinda skeered at first!

 

[a_kelley]

Try some plcc if you want really fun. Or bga