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DR650 EFI Conversion Update

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Well I finally reached a point that I feel like I can say my EFI conversion project is a success so I thought I would post an update along with a video of a short demo ride.

So basically, I had everything running back in January and was riding it daily but continued to have the problem of intermittent stalls on return to idle. About one in every 5 to 10 times I came to a stop, it would die. :lol: Sometimes it happened much more often and sometimes less. It was driving me nuts. I kept playing around with the fuel maps and other tuning factors but noting I tried had any effect. And on the data logs, the pulse width looked good. What the &%$#@! is going on? The only thing that the MicroSqurit (MS) ECU CAN control is the injection PW and it looks good. I even installed a fuel pressure gauge that I could watch while I ride but the pressure was rock solid. :cry: It finally dawned on me that it was not the PW but the timing of when the injection was taking place within the engine cycle that was causing the problem. More information below for anyone interested in the details but the work around was to go to two injections per cycle with ½ the injection time for each. That solved the problem. The bike runs so good now I just love riding it and can’t stay off of it. Any excuse for a ride and I am gone! :p

Video link here:

For those that may be interested in the boring details I offer the following. Warning, this may be way more than you ever wanted to know about EFI if you are not a techno geek like me. :cry:

:p First a little EFI background information. There are basically 3 injection timing schemes available with the MS and each requires different timing information.

The best is full sequential which allows the tuner to specify exactly when in the 720 degree cycle the injection is to take place. This requires a multi tooth crank wheel like a 36 -1 (36 tooth and one missing) AND a cam sensor with at least one tooth. (Note, this what MXrob used and why he never saw the idle issue I have been fighting. :ride: )

With a toothed crank wheel but no cam sensor, the ECU knows where in the 360 revolution it is but it can’t know if the engine is on a compression stroke or exhaust stroke. But it can still do Semi- sequential, which does an injection every revolution with half the calculated fuel required for each firing cycle and allows the tuner to set the timing or angle for the injections. This what i would really like to get to.

The simplest mode is Untimed Batch used with basic trigger. It does not really know where the engine is in the cycle and just fires the injection pulse when it gets a timing trigger, once every full 720 degree cycle. This is what I am using because I am triggering off the spark coil.

In theory, the injection should not happen when the intake valve is open. This seems backward at first but in practice, most engines run MUCH better when the injection is done on a closed intake valve. The Theory behind that is that it allows time for the fuel to more completely mix with the air, helped by heat from the intake valve. For whatever reason, it seems to work much better. This is much more important at idle than at high speed.

So in my original setup I was injecting right after the spark coil trigger every other revolution or once per power stroke. And it never knew which cycle it was on. There was a 50/50 chance thing every time I cranked up the motor. When it was on the intake stoke case, the injection was taking place just as the valve opened which is exactly the worst time. :p The code does not support doing semi sequential with my basic trigger but by going to two injections per firing cycle (one per revolution) I now have only ½ the fuel going in with the valve open and ½ when it is closed and it is consistent every time. This made a HUGE improvement! :lol: I am still trying to figure out a way to “trick” the code into doing semi sequential but I don’t hold out much hope. It is running so fine now that I hate to mess with it but there is that nagging voice in the back of my head saying it could be even better. . . . :lol:

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I am using the TB and fuel pump from a LTR-450 quad. Also the MAP (Manifold Air Pressure) sensor and IAT (Inlet Air Temp) sensor. I shamelessly copied the good work done by MXrob on his DR650 EFI project in that area.

Here is a link to my original write up if you are interested.

. http://www.thumperta...-project-dr650/

Let me know if you would like any additional information.

Thanks,

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Shoot... I was just in Orlando last week. I think you live around there ?

I would have loved to come by and see it to compare to the Ecotrons kit I have on mine. Oh well :cry:

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Thanks RC. Darn, I wish I had known you were in the area, I would have loved to get with you and compare notes. As for the dyno, I would like to do that but it will not be any time soon. I am about to head West for a long road trip on the V-Strom. Coast to coast the long way ( Orlando to Portland OR) , and won't get back until late August or September. I am looking forward to the trip (my third C to C and back trip :cry: ), but I hate that I will not be able to play with the DR till I get back. :cry:

Are you working on Ignition control? I would be very interested to hear how that works out. I think your kit uses the stock VR sensor and the two long teeth on the rotor so no need for a new toothed wheel. Is that correct? Love to know more about how that works.

John

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Hi All,

A little addendum.  I have just completed a fuel injected DRZ400.  I used a LTZ throttle body (basically the same as above).  In the new version of Microsquirt code (MSEXTRA) there is a function to use a blended Alpha-N - Speed-Density specifically called ITB (independent throttle body)  This is designed to use the MAP sensor in the places of the load table where it works well and TPS where there is no appreciable vacuum. This allows a better load table over all. Added to that specifically for single cylinder applications there is the ability to read the map sensor on the first few revolutions of the engine to determine where abouts in the cycle the engine is to allow sequential and semi sequential injection.  This is in place of a cam position signal.  I have gone a step further and removed the CDI unit  - replacing it with a S15 Coil from a Nissan Silvia and firing it from the Microsquirt. All of this is triggered from a 18-1 toothed wheel (ring) that I had made and slipped on the existing flywheel (using the stock pickup).   I have a spark map from an after market CDI unit for the DRZ thanks to ohiodrz400sm from the DRZ400 forum. (and this works sublimely) 

 

the build can be seen here:

 

 

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12 hours ago, roleyrev said:

Hi All,

A little addendum.  I have just completed a fuel injected DRZ400.  I used a LTZ throttle body (basically the same as above).  In the new version of Microsquirt code (MSEXTRA) there is a function to use a blended Alpha-N - Speed-Density specifically called ITB (independent throttle body)  This is designed to use the MAP sensor in the places of the load table where it works well and TPS where there is no appreciable vacuum. This allows a better load table over all. Added to that specifically for single cylinder applications there is the ability to read the map sensor on the first few revolutions of the engine to determine where abouts in the cycle the engine is to allow sequential and semi sequential injection.  This is in place of a cam position signal.  I have gone a step further and removed the CDI unit  - replacing it with a S15 Coil from a Nissan Silvia and firing it from the Microsquirt. All of this is triggered from a 18-1 toothed wheel (ring) that I had made and slipped on the existing flywheel (using the stock pickup).   I have a spark map from an after market CDI unit for the DRZ thanks to ohiodrz400sm from the DRZ400 forum. (and this works sublimely) 

 

the build can be seen here:

 

 

Pretty cool (an EFI DRZ), have you posted any more detail in the DRZ forum?

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1 hour ago, zig06 said:

Pretty cool (an EFI DRZ), have you posted any more detail in the DRZ forum?

Only what you can get to in that DRZ link that I included.  Always open for questions though.  I'm waiting on some dyno time to get to the hard to reach load places - that will be after Christmas. 

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