VP44 Standalone ECU Project

Dug into the circuit a little more today, getting closer to the signal I wanna see. In the first scope capture I’ve got the reference voltage set so that I’m getting a pulse for every tooth on the tone wheel of the VP but it’s a pretty messy signal. Adjusted it a little more for the second capture so that I’m only seeing 6 low spots in the tone wheel that will ultimately be used as the reference point to time the injection events. Not ideal but I’m thinking that’ll be enough to get things started. Gonna try to find something that’ll give me a little better signal, maybe a comparator with less hysteresis will do the trick.

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Been a little busy lately between long weekends and getting my truck ready for a hill climb. Finally got some time to sit down tonight and play with this a little more. A small capacitor across the output of the op-amp circuit was enough to kill a lot of the noise, still not thrilled with the outcome but it’s much better than before. I’ll redo it when it becomes a problem.

Pieced some code together and I’m finally starting to get what I want, the arduino is taking my circuit output and reading it as a digital input then the code is turning that into an rpm value that can be displayed. Now the hard part is gong to begin where I have to use that rpm as a variable in a reference table to create some sort of idle map. Might need to get my hands on a VP truck to take some measurements.

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I’m keepin an eye on this. I like this technical stuff. I may not be to much help but but I’m willing to give input on the stuff I do know
 
No real progress to add but I did get my hands on a core hot rod VP for cheap. I’ve always heard that hot rods are an HO pump with an SO pump head and that the HO pumps have a more aggressive cam ring. Hard to say whether or not it’s more aggressive but it’s definitely different. SO cam ring is on top, HO cam ring is on the bottom, pump elements rotate clockwise in this picture. Both cam rings are pinned together.
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Hill climb went really well for my first time. First day in the DOT class I got killed by all the lighter gas stuff running cut boggers but still had some fun. The second day I ran in the any tire class with some paddles on the rear, didn’t get knocked out of eliminations until my 5th pairing. The truck ran awesome and held its own against some pretty quick gas stuff, seemed to draw a lot of attention in a good way. Got a little squirrely off a bump on my last run in the semi finals and had a run in with a snow pile, looks like the grille is the only damage. Back to the VP stuff this week.

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matty169 said:
Where you located?
Anywhere near Wisconsin and I'll drop off a VP truck to use for your experiment.
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I'm in the Metro Detroit area, I appreciate the offer but that's a little ways out. Got some local VP guys I can ask when I'm ready.
 
zachu812 said:
Hill climb went really well for my first time. First day in the DOT class I got killed by all the lighter gas stuff running cut boggers but still had some fun. The second day I ran in the any tire class with some paddles on the rear, didn’t get knocked out of eliminations until my 5th pairing. The truck ran awesome and held its own against some pretty quick gas stuff, seemed to draw a lot of attention in a good way. Got a little squirrely off a bump on my last run in the semi finals and had a run in with a snow pile, looks like the grille is the only damage. Back to the VP stuff this week.

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This needs a vid to go with that busted grill pic. That chit looked crazy.
 
Back on topic, did some googling and found something extremely helpful.

http://www.freepatentsonline.com/4727323.pdf

I'm fairly certain that this is a patent for the type of sensor that's inside the pump. The two output's I've been reading are essentially two different sensors that are placed really close together. This was probably required for some complex engine position management software in order to precisely control injections. For what I'm doing this probably isn't necessary.

With the help of a coworker I got a better handle on the kind of circuitry that I need to process these signals. The plan now is to use an op amp and AC couple one of the sensor outputs in order to remove the DC offset, that way I'll only amplify the ripple. From there I'll send the amplified signal into a zero crossing detector circuit to get a nice 0-5V output.

I'm thinking now I should try to set up the code in a way so that each tooth on the tone wheel is read and processed to continually send pump speed to the controller and the 6 dips in the tone wheels can be processed separately as interrupts to command injection. This way the Arduino will be continually thinking about how much fuel is needed and that will be commanded a certain time after the injection pulse is seen.
 
this is way over my head but...

has not the drag comp or blue chip or redline boxes adj for fueling over the 2800...does it not override the ecm limtations.....

and no one has had that pump to run at the max capable fueling already...

what yer doing is cool..just kinda wondering if there is actually new stuff to be found..i have a ind inj hrvp on my daily tow pig..its has made tuning a nightmare..
 
The drag comp, redline, and quad 4k all fuel well beyond 2800 but they all have their limitations. Always heard that the drag comp wont fuel past the ECMs runaway protection limit (~3500?) then the quad 4k and redline has driveability issues.

There's nothing new to be found and I'm not going to break any VP records. I'm really trying to learn something practical by doing this and I want a control system to make the pump do whatever I tell it for once. If this works out you could take almost any core VP, even with a junk timing piston or electronics, set the timing where ever you want and go to town.
 
Had a thought. Would the standalone ecu make it possible to be able to jump teeth on pump gear? Maybe get some of that timing us VP guys desire. Heard of,people trying it and it not working. Maybe this could get us there.

Just a dumb hairbrained thought I had when bored at work.
 
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