Hi
Has anyone any knowledge of or experience of the aftermarket fuel injection systems which have been developed by Burlen and also by Kee, a company in Chelmsford, please.
I am interested in this since it may provide a way for the Duchess to run better on lpg and petrol. She runs OK at the moment, but the setup is always a compromise between the needs of the two fuels. If it were possible to have 2 sets of injectors, one set for lpg and the other for petrol and 2 ecu's one for lpg and the other for petrol, then, in theory at least, when switching from one fuel to another the timing is reset and the fuelling is optimised for the selected fuel. This is what happens on modern lpg vehicles which have their own dedicated lpg ecu in addition to the ecu put into the vehicle by the manufacturer. This ecu sets the parameters for the selected fuel.
Although lpg has decreased in availability of late, it is still a good, clean and cheap alternative to petrol and it makes the Duchess so cheap to run (no tax and comprehensive insurance at less than £100 pa). I can buy (sometimes!!) lpg at 55p per litre which means that with petrol at 115p per litre and the Duchess doing about 22 mpg on gas the mileage in cost terms is about 45 mpg price equivalent. Even at 65p per litre the consumption is 39 mpg price equivalent, so good news. I do about 5000 miles per year so it costs me, excluding maintenance, about 16p per mile.
I think that fuel injection is a much more controlled way of delivery fuel to an engine and I would like to install this in my car if possible. So a long road begins!
Hi
Has anyone any knowledge of or experience of the aftermarket fuel injection systems which have been developed by Burlen and also by Kee, a company in Chelmsford, please.
I am interested in this since it may provide a way for the Duchess to run better on lpg and petrol. She runs OK at the moment, but the setup is always a compromise between the needs of the two fuels. If it were possible to have 2 sets of injectors, one set for lpg and the other for petrol and 2 ecu's one for lpg and the other for petrol, then, in theory at least, when switching from one fuel to another the timing is reset and the fuelling is optimised for the selected fuel. This is what happens on modern lpg vehicles which have their own dedicated lpg ecu in addition to the ecu put into the vehicle by the manufacturer. This ecu sets the parameters for the selected fuel.
Although lpg has decreased in availability of late, it is still a good, clean and cheap alternative to petrol and it makes the Duchess so cheap to run (no tax and comprehensive insurance at less than £100 pa). I can buy (sometimes!!) lpg at 55p per litre which means that with petrol at 115p per litre and the Duchess doing about 22 mpg on gas the mileage in cost terms is about 45 mpg price equivalent. Even at 65p per litre the consumption is 39 mpg price equivalent, so good news. I do about 5000 miles per year so it costs me, excluding maintenance, about 16p per mile.
I think that fuel injection is a much more controlled way of delivery fuel to an engine and I would like to install this in my car if possible. So a long road begins!
This is something I am working towards on my RV8 powered landrover at the moment - the P6 is off the road awaiting a replacment steering idler, and after just over a month of getting 20mpg in the Defender I have decided it's time to take action! I have been thinking about this for years, and had bought the LPG injectors (Valtek type 34's). Yesterday I took delivery of the other LPG gear i need to progress (vaporiser, shutoff solenoids, filters, pipework etc)
The vehicle is already fuel injected with Megasquirt, which is also driving Ford EDIS based crank triggered ignition. My plan is this:
The slight complication is that the petrol injectors are high impedance, and the LPG ones are low impedance. The two ways around this are to:
- Fit LPG injection front end (the vehicle was previously LPG'd with a mixer ring induction setup)
- Switch between LPG injectors and Petrol injectors using MS to trigger the change when the coolant is up to temp. Fuelling and timing maps will change simultaneously.
- I plan to add an input to the MS so that I can monitor gas line pressure and set the MS to switch back to Petrol if it drops below a set figure (This will need to be determined from datalogging AFRs and line pressure).
- A switch will be fitted on the dash to allow you to manually select either fuel if necessary (this will only allow you to switch to LPG if coolant temp and line pressure is ok, but will allow switching over to petrol at any time)
- From a safety point of view the MS will shut off the LPG solenoids after 3 seconds if the engine is not running (it does this with the petrol pump already).
The other complication is that my wideband oxygen sensor died a couple of weeks ago, and I still need to replace it.
- Run resistors in line with the LPG injectors to make them appear high impedance to the ECU. This has the benefit of being cheap and easy, but the downside is increased injector deadtime (apparently).
- Use on of the available "Peak and hold" PWM boards and use this drive each set of injectors in PWM mode, simply switching the +12v supply between each set. This will give better deadtime figures but adds some complexity and cost.
This is a priority for me to get running, as it means I can save some money, and keep the P6 off the salty roads this winter and give it some TLC (after it doing stirling service being my daily for the last few years - check my fuelly stats to see!) however with a 3 month old baby I don't have the free time I once did for projects like this, i'll be trying to grab the odd hour here and there on it as I can.