Last week I started hacking apart the extra set of PC800 carbs and drilling into them to accept fuel injector bungs. I am using a Dremel tool and a cordless drill to do the work. All of the drilling and Demeling is done outside with a fire extinguisher close at hand in case some residual fuel decides to light on fire.
I used the very small hole in the side of the carb as a guide for where I want the injectors to come through.
Just after I took this photo, my Dremel tool failed. Most of the internals of the float bowls have been cut out. I still need to drill it out enough to take the injector and cut out a bit more of the float bowl parts. Hopefully in another few days, the parts will come for my Dremel to get it back online. It appears that the brushes burned out. Hopefully the motor controller is still intact and working properly.
In other fuel injection-related news, I made a big purchase today from DIYAutoTune.com for a MicroSquirt, a wide-band O2 sensor, and several other sensors. Now, aside from a few relays that are still to be purchased, I have just about everything I need to assemble this project and get it running. With how much money I spent to get here, this is both very exciting and very scary. Hopefully it works and I didn’t waste my money!
Keep us updated on your progress… I’m following it with interest… I’m thinking about finding the cheapest set of carbs on ebay and doing somthing very similar, though I would be rolling my own engine controller.
I was thinking about cutting down the slide pistons to a smaller length, then bolting them into position for easy removal. The remainder of the piston slides would then hold the fuel injectors in place.
Running a wet manifold injection system, injection system would fire when the sparkplugs go off, and the injection pulse duration would depend on engine RPM’s and throttle position (mount a pot on the throttle command shaft).
The big adventure would be coding the injection management in less than lines of code to fit on a picaxe chip !
Not planning on using an oxygen sensor though, at least not yet….
Cheers,
Daniel
Hi Daniel,
There are a couple additional sensor inputs that you would probably want including manifold air pressure, coolant temperature, and manifold air temperature. It would also be useful to have ambient air pressure and, as you mentioned, an oxygen sensor. A friend rolled his own fuel injection computer for a Datsun pickup with good success. I would have gone the same route had I the time and experience to fab my own system. At the moment, I’m even having trouble finishing the fuel tank modifications due to time constraints and the friend with a welder living 45 minutes away. This nice summer weather is making me go play outside rather than work on this project. Never fear though! I will finish it up at some point this calendar year. I have it about 70% done at the moment. The remaining tasks to complete this project are all lined up and waiting for me to have the time and machine shop capabilities. The only thing that is giving me trouble at the moment is finding a happy home for the oxygen sensor to attach to the exhaust system. Otherwise, I’ve solved (at least on paper) just about every other problem.
Cheers,
Douglas
> Less than 200 lines of code. Did not notice that my numeric keypad was off!!