When I removed the stock ignition coils, I neglected to secure two ground wires that had been held by one of the ignition coil bolts.
One little bolt and the lights are back on!
Now I just need to fix everything else. I'm looking for the ground wire that will fix the throttle body issue... Wish me luck.
I acquired a small oscilloscope. The jury is still slightly out as to whether it's appropriate to the application, but so far, so good...
There are some limitations to the instrument. The LCD display is not particularly high resolution, so sometimes it's hard to see the whole story at once. Likewise, there no external trigger input, so the missing pulse nature of the trigger wheel signal is difficult to sync. One has to adjust the sweep rate low enough and manage to capture an entire revolution with the memory function to analyze the finer points and the LCD resolution limits how much you can see at that level.
Even so, I was able to see a few things. First, the slightest eccentricity in the trigger wheel mounting is very easy to detect and could indeed be a contributing factor to my EDIS ignition problems. The VR sensor input ranged from 5V p-p down to 0.5V p-p. It's difficult with the resolution of the display to configure the scope to show both ranges. That alone could affect the EDIS module enough to cause some problems.
Working on a related theory, I set the sweep rate very slow and watched the average amplitude of the VR sensor signal. I arbitrarily decided that low RPM was "normal". As the RPM went up, the amplitude went up to about 5V, then began tapering off, fairly quickly, to "normal" levels. Since the engine would not rev beyond about 5500 RPM, I am supposing that the stock VR sensor may not have the frequency response needed for this application.
Putting a little math to it, with the one pulse per rev stock trigger, the signal at redline would be about 9500 Hz, or 9.5KHz. With the 36-1 trigger wheel, the signal would be more like 332KHz to 342KHz, depending on how you count it. Keeping in mind that there are radio signals at lower frequencies than that, it's not surprising that maybe the sensor is not up to the task.
It is under this working theory that I decided to, at least temporarily, return the ignition to Yamaha stock. This means I lose my cute purple wires and those "wrath of Thor" lightning bolt sparks, but it could return me to fighting a single front war.
It turns out that it may be worth it, for now I can rev close enough to redline to cause the involuntary retraction of certain parts of my anatomy, and I'm not even riding at the time. There is some detectable miss in the rhythm, especially noticeable at low RPM. I may be suffering the famous Yamaha weak ignition problems, so I will still be searching for a long term solution, perhaps for Dyna coils or maybe driving the coils directly from MegaSquirt, maybe even with big enough drivers to run the EDIS coil. For now, however, perhaps I can march on with fueling issues and determine if I can even operate Buzz on these (quite likely too large) throttle bodies. Down that road are a few possibilities, from cutting my throttle body assembly in half and fabricating a manifold, up to and including restoring Buzz to stock and putting MegaSquirt on something else, probably the VW trike. My wife would like to see me get that thing on the road regardless.
I also shoehorned in an oil and filter change, which was probably overdue even when I parked Buzz last May.
Today, before I posted this update, I was explaining the issues to a friend when it suddenly occurred to me that the EDIS module itself may have a rev limiting "feature". This could make sense because my module and coils came off a Tempo or Escort or some similarly pedestrian vehicle, RPM-wise. Web research, including in MSEFI forums, indicates that the jury is still out. Several people describe similar rev limitations, generally around 6000RPM, but some testing has shown 8000-9000 RPM as a limit.
I'm wondering if the VR sensor could *still* be the issue. Once one exceeds the sensor's ratings, the module gets bad or no info about the crankshaft position and speed, so it stops firing. The engine RPM drops, the signal gets usable again and there it goes. Consequently, the Ford sensor may not work much better. Furthermore, the limit may indeed be a feature of the EDIS module itself, and that may explain why others *not* using Yamaha sensors on their EDIS modules are having similar problems.
One possible solution may be an optical sensor that may not would not be so frequency dependent. I will keep looking, but for now, I really want to get on with turning the fuel and maybe getting Buzz on the road, so it's stock sparks for me.
All this, and I still haven't properly investigated the throttle-failing-to-close-completely issue...
In short, this should be essentially half of the throttle body assembly from the 636. Rather than having to modify what I have, this is ready to go. I will need to fabricate an intake of some sort, but I have a couple of ideas in mind.
In the mean time, I'm still going to see if I can get a ride out of Buzz on New Years Day. That seems a great way to start the year....
I built a fuel feed and return thingy that bolts in place of the stock petcock. I neglected, however, to photograph it before I installed it. With luck, we'll never see it again. It is quite simply a 5/16" tap for feed and an elbow with a 1/4" hose barb for return. It's actually a single part found on the shelf at AutoZone that I cut. I cut a piece of 1/8" plate into the proper shape, drilled two 1/4" holes to mount it. The OD of the tubing is .370 and I had a drill bit that was .373, so I drilled two holes for the tubing. I put those two too close together, however and I had to angle them away from each other to allow for clearance to put hoses on the tubes. I brazed the tubing in, wire brushed the whole thing, cut a gasket and bolted it up. Voila!
This is an intentionally simple design with no valves. I will procure a suitable feed valve and locate my existing return valve and install them soon. Besides the safety issue, it's tough to have to drain the tank each time it's removed, so the valves will definitely go on sooner rather than later.
I had previously drilled a hole in the tank for fuel return. I got a flanged bolt, put a gasket on it and used a piece of wire to pull it through the inside of the tank. I put a washer and nut on the outside and applied LocTite. Hopefully, that's the last of that, too.
After that, it was just a matter of putting the tank back on (and rerouting hoses), buttoning up the wiring and putting the seat on.
The front tire needed air and I felt obligated to lube the chain.
The ride down the road was a LOT more fun than the push home...
He ran pretty good, actually. I went down my street a couple of blocks, jumped over a block and was headed back toward the main street when Buzz suddenly bogged down and died. He restarted easily, so I figured I just didn't have enough gas in the tank. I went back to the house and put in about a gallon. My plan was to take him to the car wash, knock some dust off and come back. I decided that if I had troubles, I didn't want to be on the main road, so I went to a parallel side street and headed for the carwash. When I went over the hump crossing the next street, he died again. This time he didn't restart.
I pushed him up in a nearby parking lot where there was some light and had a look. I noticed that the fuel pressure wasn't coming up and I didn't hear the pump running. I pulled the seat off and found that the fuel pump fuse was blown. I didn't have a spare 5A, but I did have a spare 10A. I put that in and it didn't blow, but the pump didn't run, either. I pushed him home from there. It was only two blocks.
I suspect something pinched. It's too dark to troubleshoot now. I'll take a look tomorrow.
I replaced that one, put a 5A back in the fuel pump fuse holder and verified that I had power to the connector. I turned the key off, plugged in the connector, turned the key on and SNAP! The 5A blew with considerable alacrity.
The coil on the motor reads a pretty normal 1.5 ohms, so my second theory that some debris has jammed the impeller seems likely. Stall current would be about 8A.
I have looked around... A fuel pump from a local bike salvage yard (which moved across town, much closer to me now!) is still a bit high. The one model he has several of and thus charges the least for is still $150. I can get them all day on eBay for half or less of that, but I can't just walk into eBay and pick one up....
Before I purchase one, I will pull the pump out and see if I am lucky enough for the debris to be lodged in the back of the pump where it can be removed or flushed backward or something before replacing it..
In related news, it occurs to me that I may be able to use these throttle bodies for a while longer by lowering the fuel pressure a bit, delivering less fuel, thus perhaps get a leaner minimum mixture. As it stands, at idle the injectors are opening for what is just about as short a period as possible and it's delivering too much fuel. The regulator I have is the hard set unit that came with my salvage fuel pump. It appears to be set to about 43 psi, which is pretty much normal. I ordered an adjustable regulator which will run 0 - 100 psi. I think I am going to try about 35 or so to start with.
While I'm doing all this fuel system work, I think I will wire in that tilt disconnect switch that I'd forgotten about... And since I forgot about the other inline fuse holder between the battery and the relay, I will update the wiring diagram, too.
I have found several suitable pumps on eBay. Just waiting on the first auction to end
I looked into connecting the Honda tilt switch, but it will need a little bit of electronics to work. The tilt switch is open in the normal upright position and "closes" to 23K ohms when tilted. A single transistor and a resistor or two is all that will be needed to connect it.
In the mean time, I'll be updating the wiring diagrams and impatiently awaiting the new pump.
This evening, I pulled the old pump back out and discovered, as I suspected when I opened the package, that the new pump is slightly smaller. As you may recall, a neoprene sleeve joins the body of the pump with an adapter I built. This adapter allows the pump, originally designed to reside submerged in the tank to instead be fed from a fuel line.
Well, the new pump, which I neglected to photograph (you can't get good help these days), is enough shorter that there is only a small fraction of an inch of actual pump showing beyond the adapter. Also, the body of the pump is smaller in diameter, but not so much that the neoprene and hose clamp couldn't seal it. I soldered pins on the wires and put them in a connector, plugged it in and verified that it would run dry. It was quite noisy, which surprised and concerned me at the time.
The new regulator is bigger than I'd hoped, but not as big as I'd feared. I took the adequate but busy stock gauge off and substituted my spiffy oil filled one. As for mounting, the size of the regulator would not turn out to be the problem.
The regulator has a straight hose barb for input from the pump in what I'm going to arbitrarily call the 'back'. In the front is the fuel pressure gauge. Sticking out from the lower right is another straight hose barb for the fuel return. Above that is a vacuum fitting (used to modulate the pressure according to vacuum; I will experiment with this, but for now, I have it capped) and finally on the top is the pressure adjuster screw. In short, the unit is roughly cubical in shape, but in operation, you need access to four of the cube's six sides. I saw no point is orienting the device where the gauge could not be seen, so it pretty much had to mount with the gauge facing outward. After LOTS of trying and tweaking and test fitting, I finally decided to put it at an angle with the return fitting facing at about a 45 degree angle. The gauge is in almost the same position as before. The assembly is nestled between the air filters for 1 & 2, forcing the bottom edges of each to rotate out slightly. Filter #1 is almost vertical but #2 is angled more. Filter #2 isn't normally visble, so I can tolerate it. Even with all this difficulty, the fuel system plumbing is simplified, largely because the pressure gauge fits on the regulator itself. Upon reflection, I can replumb the system with the regulator placed for better access to the adjuster and with the fuel pressure gauge remotely mounting where I can see it while riding. I have some ideas about that, too.
The engine is not running in this picture, but the system holds pressure well, indicating about 30 here. I have the regulator set to 38 psi, down from the fixed regulator's 45ish. I had to reroute the return line, which involved accidentally pulling the line off the tank, which started it pouring. Argh. The clamp is on there much better now.
Then I had trouble getting fuel to start flowing. I think the filter element was wet (with fuel), so gravity couldn't produce enough pressure to push the air in the line through the filter. I used the trust old siphon bulb and got it flowing. Once some fuel was flowing through the pump, the noise went away and now it sounds like it should, a tiny little whine. Likewise, the regulator has a quiet little honk while running with fuel, but when I used the air compressor to verify the the input and return, it sounded like an air impact wrench.
After all that, I finally was able to hit the starter button and Buzz leapt to life! While he was warming up, I unloaded all the tools from nooks and crannies and put the seat on. I took him down the street, around the block. I didn't have to push him home, not even once.
I think he runs a little better on the lower fuel pressure. It's hard to tell because the previous ride was so useless. In any case, Buzz runs at least as well has he did before the conversion, which is good, but not great. Good power on acceleration, but it could be quicker. It felt like I was rolling the throttle on, when in fact, I'd nailed it. In other words, rather than Vrooomm, it was more like Vrrrrrrroooooomm...
After circling the block and a little farther for several laps, I actually managed to get about 4 miles on the odometer. I then went to the gas station and filled the tank with 93 octane and endeavored to ride more. I spent more time on long straight streets with minimal stops. At the time, I was not brave enough to hit a freeway. I will try that in the warm daylight, just in case. In all, I clocked about 12 miles with no troubles.
At speed and very low throttle openings, it runs pretty rough. I'm pretty sure this is because at low consumption levels, the granularity between enough fuel and too much fuel is pretty narrow. At higher throttle openings, he seems to run really well.
All in all, a good day!
Of course, I had to show him off, so three trips outside and at least one more planned. Since the car wash was closed last night (and since the ECU isn't actually waterproof at this point), I'm glad I spent 5-10 minutes using the Armorall Exterior Detailing Wipes to clean him up a bit. Made the shiny bits shiny. He's been parked unwashed for the better part of a year.
On that subject, it came to my attention that my first blog entry on this subject was January 10, 2008. Today marks one year, pretty much to the day, since I got serious about the project. Now, I didn't start taking Buzz apart until March 20, but the actual project, from "yeah, I'm gonna do it" to riding a fuel injected Buzz to work was one year.
There have been many interruptions along the way and gaps during which little tangible progress was made. I have re-engineered a few things along the learning curve. Knowing what I know now, once the parts were gathered, a conversion like Buzz has turned out to be as of today, would probably take me about a week of evenings.
I do not consider the project finished yet. Buzz still runs rich, especially at low RPMs. I still need to adjust the valves and bolster the ignition system. Since I'm planning to Squirt the VW trike, I may order a MicroSquirt and put it on Buzz and use this ECU for the trike. MicroSquirt is ready out of the box to drive two coils. With the adjustable fuel pressure regulator, I hope to be able to rein that in. If not, I have the other throttle body and the intake fab *that* will require. I still want to put a wideband O2 sensor in there.
Of course, none of that addresses the cosmetics I have in mind for Buzz.
In any case, it's lunchtime, time for another ride....
The ride back to work was fine. I had a BTW meeting to attend, so I took Buzz there, too. I took a very short jump on the freeway, but it was a very windy evening and I don't like getting shoved around so much. A few people there have been loosely following the progress. They were pleased to see Buzz on the road, although they would be more pleased to see the VW trike on the road.
After the meeting, I met my wife at work and we took a slightly long way home, by way of the local watering hole. Buzz ran reasonably well the whole way.
Overnight, I forgot to turn off the fuel valves, which would not normally be a problem, but apparently something was leaking. I turned it off, but it was a while before we would be going anywhere, so it was all dry by the time I got to troubleshoot a bit. I'm about 90% sure it was the inlet to the fuel filter, and since tightening that clamp, there does not appear to be any other leakage.
Especially after the leak, the tank was pretty low. It took 2.8 gallons to top him off, and with only about 50 miles run, that works out to 17.5 mpg. An undetermined amount of fuel went on the ground and I still have not done any tuning. We rode some on Saturday and some on Sunday, including a few miles on the freeway and a few minutes of twisty maneuvering in an exceptionally smooth parking lot. Buzz is a lot of fun to ride, overall, although at very small throttle openings, he runs pretty rough. I haven't had the chance to top off the second tank yet and it doesn't appear to be leaking anymore and even with a really rich mixture, I expect his mileage will go up.
Getting to ride Buzz and having him behave pretty well really helped because, wise or not, I began adding up the money I've spent thus far.
I had an envelope that had a few receipts in it. I consulted my eBay and PayPal records for more. Last night I dug through a stack of receipts at the house. I have another stack to audit from a desk drawer at work.
I have not found every receipt, but I have most of them. Some of the figures I have, especially ones I gleaned from my bank statements, are for the full purchase amount for transactions where it's quite likely that not everything was for Buzz. I have dithered back and forth one whether to count tools and/or supplies bought during the course of the project. Arguably, I would not have needed them all without working on Buzz, but they are still usable for non-Buzz tasks. Likewise, do I count things that I bought for Buzz, but either lost/damaged and had to replace or just didn't end up using? There are also a couple of things left to buy, most importantly some form of O2 sensor, preferably wideband.
I will post an itemized list or two later, but for now I can say that converting Buzz to EFI, before O2, ran somewhere between $915 and $1925, depending on how you add it up. More than half of that total was split between DIYAutotune, Del City and K&N Filters. The auto parts stores and the hardware stores got the majority of the rest of it. Ironically, the critical components like the throttle bodies, fuel pumps, etc were fairly cheap parts. It's the little stuff that adds up. In reviewing other people's MegaSquirt projects, I expected about $1000, but not $2000. By that last figure, the EFI system is worth twice what the bike is...
In the full analysis to come, I think I will be able to show that it *could* be done cheaper by cutting corners in certain ways, such as using solder and tape splices wherever possible rather than connectorizing everything, or even by using cheaper connectors. I could have used cheaper air filters, worked around the neoprene reducers, etc. Organizing my shop would help keep me from having to purchase the same materials twice due to loss. Haste makes waste, too. If I'd not rushed to ride, I may not have forgotten the filter and with that, would not have destroyed the first fuel pump. Similarly, "gotta have it now" costs more than shopping around.
The experience I've gained will greatly benefit the next project, most likely the VW trike. Some of the issues that apply to a bike may not apply to the trike at all, saving me all kinds of money and time. Plus, I already have a lot of tools...
With the bike warmed up and idling, I reduced FP from 45 to 20 psi. Idle is a bit smoother and though I do not yet have any sort of EGO sensor, my built-in unburned hydrocarbon detector (nose) seems to indicate that it's not nearly so rich. No-load reving reveals MUCH less black/gray smoke as well. I was able to create a rather James-Bond-y smoke screen by reving up against my fuel cut rev limiter. Not so much, now.
I hope to get in at least a short ride this afternoon, if for no other reason than to see how Buzz rides now.
The theory I'm working on is that a required fuel setting of 1.8 for (4) 245cc/min injectors is just too rich and the pulse width probably can't get any shorter reliably.
By reducing the pressure, I have essentially changed my injector flow rate to 166cc/min. The injectors may not atomize the fuel quite as well at this lower pressure, but the observed effect on Buzz seems to be an improvement.