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ecoxantia · 08-28-2008, 05:14 AM

Thanks dcb.

This is the injectors at idle, 800rpm.
The picture in my previous post is at about 1900rpm.

So yes, you can see spacing varying with rpm.

The system does have a fuel pressure gauge! From the data I have it looks useful too - 0.5 volts at 100bar, 1.3 volts at 300 bar and assuming it's linear then 5 volts is about 1300bar, corresponding to max pressure.

I think this is the best solution since pressure is not quite linear with rpm, as there is a switchable 3rd piston in the injection pump. This is the "high presssure" piston. The idea is to only use highest pressures when necessary, so this 3rd piston is switched off in certain conditions. You can see why - 1300 bar don't come for free!!

So, next step - get the Arduino to grab the pressure. I have not even looked at the code so that's next...I seem to remember the memory is pretty full already, no?

08-28-2008, 05:14 AM	#15 (permalink)
ecoxantia EcoModding Apprentice Join Date: Aug 2008 Location: UK Posts: 104 Fizz - '06 Skoda Fabia Combi TEAM VW AUDI Group 90 day: 56.62 mpg (US) Thanks: 3 Thanked 9 Times in 7 Posts	Thanks dcb. This is the injectors at idle, 800rpm. The picture in my previous post is at about 1900rpm. So yes, you can see spacing varying with rpm. The system does have a fuel pressure gauge! From the data I have it looks useful too - 0.5 volts at 100bar, 1.3 volts at 300 bar and assuming it's linear then 5 volts is about 1300bar, corresponding to max pressure. I think this is the best solution since pressure is not quite linear with rpm, as there is a switchable 3rd piston in the injection pump. This is the "high presssure" piston. The idea is to only use highest pressures when necessary, so this 3rd piston is switched off in certain conditions. You can see why - 1300 bar don't come for free!! So, next step - get the Arduino to grab the pressure. I have not even looked at the code so that's next...I seem to remember the memory is pretty full already, no?