VP44 Standalone ECU Project

Think I figured out the problem with the sensor circuit, I had the sensors running to the non-inverting input with the inverting input grounded. Didn't really click until I looked at a pinout and remembered hearing that the inverting input is generally more stable. I went to change the wiring permanently after testing the fix and realized I forgot to pull power after a small spark. Got another to replace it so we should be all set.

joefarmer said:
Sounds like fun! What IC is it?
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It's the LM1949. Had some trouble finding an NPN that will support the current the fuel solenoid needs while having a low enough base current that the LM1949 will run it ok. Got something that's on the edge of both specs, fingers crossed it works.

zfaylor said:
It is cool to see this go down but on a serious note if you plan to make this a money making venture once it is all complete I wouldn't show too much...

A lot of companies in this industry have zero morals and would gladly steal the fruits of your labor.

Keep kicking azz though it is impressive!
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Thanks for looking out. With all the EPA stuff going on I don't feel comfortable trying to set this up as a money making venture, a few years ago maybe but I don't want the liability now. Think I'd rather just make it open source and allow others to fill in the gaps and make improvements.
 
Same here, I was hoping to find something a little more modern without getting into an ASIC thats run by a uC. We use something similar in modules at work, pretty cool how smart these drivers are but I think it's a little over the top at this stage in the project.

Do you happen to know of any other simple peak and hold drivers? I couldn't find anything I liked in my search.

Haven't really messed with any FPGA stuff before, I'll have to do some reading.
 
I normally fall back on NXP for the high power automotive stuff. I don't have a specific IC in mind, but I'll look for one.
 
I came across the TI DRV110 yesterday, looks like its just for general solenoids but I'm not seeing a reason it wouldn't work for an injector solenoid when configured properly. I like that the peak-hold ratio is configurable with that ASIC so I can make adjustments and it's a MOSFET driver rather than NPN. An LM1949 is already on the way so I'll try that and go from there.

The pump sensor circuit is doing the same thing as before, thought I fixed the problem with the changes I made but I must've missed something. Gotta take a better look at things, maybe see if I can change the zero crossing threshold to match the sensor output. I've got a feeling its related to the capacitive coupling.
 
Offroa said:
http://dmn.kuulalaakeri.org/dmn-edc/
Pretty interesting read wonder if it can help any.
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I came across that site a while ago, pretty interesting stuff. I'm hoping I can learn something reading through the code.

Just realized I haven't updated in a while, got the sensor circuit working for real this time. Turns out the data sheet has some pretty helpful information :hehe:. In all seriousness I was looking at things the wrong way, once I took the time to understand what the MAX9925 was actually doing I was able to set everything up properly.

Also hooked up a test circuit for the LM1949, seems to be firing the fuel solenoid properly. Gonna have to borrow a current probe from work one of these nights and have a good look but the voltage profile across the shunt resistor looks promising.
 
Talked to a calibration guy at work that deals with crank/cam signal management, explained my plan for trying to control injections and read pump speed from the one signal. Seems that the software to pull that off might be a bit over my head at this point so we decided it's easier to have one signal whose only purpose is for controlling injection timing and another signal for reading pump speed and position.

I was able to make some adjustments to the current circuit so that it's only reading the 6 peaks on the tone wheel that I'm guessing are for injection timing. I hooked that output up to the input for the fuel solenoid control circuit and it's firing the solenoid on each pulse. This is never going to run an engine as is so it's time to incorporate the arduino and an APPS to handle the timing and duration of injections. A buddy of mine recently picked up a pump stand, once we get that up and running we're going to rig a VP up on it and hopefully get some flow numbers to see how high in the RPM range we can make some fuel.

Picking up a couple snowmobiles and a 6.7 block has only taken away more time from this project but we'll get there.
 
diesel2fast4u said:
any news on this, would love to see it happen
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Still picking away at it, ordered some more components this morning. Think I found a better peak and hold ASIC to control the fuel solenoid and I have a MAX9926 on the way so that I can have both pump sensor outputs from one chip. Making sure the hardware side is all ironed out so I'm not fighting it later.

Also found a coupler for the pump stand that'll fit, need to make a mounting plate and find some stock 12v lines I can bend to fit.
 
Got an interface board put together, at least the start of one. On the front I’ve got one of those MAX chips Brandon suggested reading both of the pump inputs and converting them to two different outputs. Out back is a TI peak and hold driver I came across that’s not working for some reason, going to replace it tomorrow and make sure I didn’t zap it. Otherwise I have a different driver to choose from that actually works. Only difference is it doesn’t have any current sensing so it can’t compensate for temp changes in the solenoid but that’s not the end of the world.

6A790E99-B64D-41D3-AC92-B3FF4B5FC6A4.jpg
 
Not really, got slammed at work the day after that last update was posted. Seems like things are starting to go back to normal finally so I'll spend more time on this.
 
Had a circuit put together on the bread board that seemed to work perfect, duplicated that circuit on some proto board and of course it's not working. Need to take a couple steps back and see what I'm doing wrong. Got some more parts to order so I can try to lay this out a little more clearly.
 
I've lit my latest project on fire several times in the last week. Kinda expensive at $220 per try. At least now you know what doesn't work. :)
 
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