rusefi.com

Hello. First excuse me for writing in English. If I knew Russian I would use it with preference

Now, what brought me on your project and forum. I have Citroen C5 2.0 HPi (2001) engine code: RLZ - EW10D, which is direct injection engine. The car is in good condition and I would like to make it running on LPG.

Easiest is to buy DI LPG ECU, however there are some problems. The engine burns some oil and it cracks the wideband O2 sensor. Second the cat. converter is removed (too expensive for replacement, moreover we bought some 2nd hand cat. converters that broke down soon after the replacement was made).
Also I suppose that the injectors aren't in very good shape, but I have no means to check that (my Chinese Lexia OBD reader doesn't work well, but I can give it one more chance).
The engine was probably overheated. The car service in my town repaired the cylinder head, new water pump, etc, however I suspect the mechanics in incompetence. The timing belt wasn't properly installed. A new spark plugs were to be installed, but I found that they installed the old ones. 1st cylinder's spark plug was welded and completely out of order.

However, now some parts are replaced. Visual inspection of the spark plugs doesn't show learn burning (they look in good shape). The pre-cat (wideband) O2 sensor is still not working.

The engine starts smoothly in warm weather and not so well in cold weather. Smell of rich fuel.

I would like to install LPG on this car, however I have the option to break the original gasoline injectors and probably completely destroying them while working on LPG.
Next, I wouldn't like to invest in specialized DI LPG ECU since I don't plan to replace the O2 sensor. From what I saw on youtube the fuel mixture should be very precise (when using both gasoline and LPG). Also I suppose that the high pressure fuel pump would fail after some time (common problem on these engines).

I don't plan to use the engine with lean mixtures, so my idea isn't replacing the factory ECU. However I would like to preserve the original injectors (as they're still working) and try to run the engine on LPG and if it is needed - LPG/gasoline mixture (to preserve the condition of the injectors).

So my first question is can rusEfi be used in "bifuel" mode? What I saw on the PCB is that it has probably 12 mosfet drivers so I guess that two banks of 4 mosfets can do the trick? I'm not aware of the correct waveform (power supply) of the original injectors, also the timing (I read that they're much quicker than the normal injectors). I can measure these levels with an oscilloscope.

Second question - the car has electronic throttle. I didn't search the site and the forums whether rusEfi can drive such throttle or not, so excuse my incompetence.

Third question - I would like to play with the electronics and the engine, but I would like to use the car as everyday car. Since I didn't make similar projects, I think it will be best to leave all the car electronics in place. I'm not sure if I have to make general re-wiring of the car electronics or not :-/ I'm not sure how the ECU works with the other modules in the car. If it is safe to preserve ABS, airbags and so on I would probably remove the original engine ECU, otherwise I'll have to put some "simulators" on it's wiring?

And last but not least - I'm driving VW Golf 4 on LPG. I see how the engine works and how the LPG ECU's proxy the petrol ECU. When some of the petrol/LPG components doesn't work properly a complete mess happens with the air to fuel mixture. So I would like to experiment also with rusEfi in order to have an ECU working in 2 modes for petrol and LPG, so the ECU knows each subsystem (petrol/LPG) in order to work properly in all cases.

Well.. I have much more questions, but this is in general. If I can get help and courage from you I would like to play with rusEfi.

PS: I have moderate to good skills in electornics, I'm using STM32L1xx MCU's in my work so I guess that I can probably contribute for the project.

All the best!

Welcome!

Everything could be done but a lot of things you are looking for are not available in the firmware/hardware at the moment. ETB support is in alpha version, we kind of work on it but slowly and who knows when it would start on a real car.

I believe direct injectors are also a bit challenging for us - both from hardware (higher voltage?) and firmware (shorter squirts are demanding better precision) sides.

How are your software development skills? You would probably need those to move these areas of the ECU forward.

Well I am doing some basic stuff. Unfortunately I haven't used RTOSes and I have no clue of the multitasking there, preemption, priorities, etc. My experience is in using the STM's periphery (ADC, DMA, timers) in a simple (loop; interrupts) program.

Simply said, anything can be done, it depends on the time spent... I have more experienced friends that can help me when needed.

Probably it is better to start a topic in the "Your car & your engine" section?
And another Q. Should I start from the Frankenso board? Am I right guessing that Frankenso is upgraded version of Frankenstein?

Yes, Frankenso is a super-Frankenstein.

Hello and welcome along.

It sounds like you have found the wiki, but just in case you have not, here's a link. http://rusefi.com/wiki/index.php?title=Manual:Hardware_Frankenso_board

I do not recall if LPG injectors are controlled the same as petro injectors. Do you know if they draw about 1A of current or if they measure about 16 ohms with a multi meter? I seem to recall a key difference with them was the how many Henries they had. I seem to recall they had more inductance, which resulted in more energy stored in a magnetic field. This results in more heat dissipated by the injectors when they turn off. If that is true, then there may be some risk that the low side MOSFET's may need a heat sink.

I am more concerned with port injected LPG on a direct injection engine. Direct injection has a much higher compression ratio, and it is likely that port injection will not work such a high compression ratio. I understand diesel buses and larger diesel direct injection engines commonly benefit from a small amount of propane injection to help increase horse power and help produce a more clean / complete combustion.

Do you work on your own vehicles? I'm confused about the incompetent mechanic, was that before you owned the vehicle? I inquire because I do not know your capabilities. Adding LPG injectors is not an easy task.

Hello kb1gtt,

Thank you for the warm welcome!

The LPG injectors (more look like valves) have 3 ohms resistance and 1.5mH inductance (specification of the most common inductor that drives the armature). I can take more measurements later.

According to Autodata the compression ratio is 11.4:1. I guess it will be OK for LPG (since LPG has higher octane rating).

Do you work on your own vehicles? I'm confused about the incompetent mechanic, was that before you owned the vehicle? I inquire because I do not know your capabilities. Adding LPG injectors is not an easy task.

I'm doing basic replacements alone. Under the supervision of a friend who is a car mechanic I am more confident and I do more things (and I ask more ). I'm more related to electricity and electronics, not mechanics unfortunately. I also don't own a garage .

About the incompetent mechanic - my father gave the car to an unknown service. There were coolant leaks and uneven work of the engine. I took the car to another car service and they found loosely connected coolant hoses, broken water pump due to over-screwing one of the bolts, the timing belt wasn't properly set. So I had to buy a new pump and new spark plugs + fees.

Is your fuel rail for the OEM a high pressure system? Do you know if your petrol injectors use 14V or do they use a higher voltage like 100V or 300V? Did this have a turbo?

It sounds like your injectors may be low pressure. Basically the same as manifold injection, but direct into the cyl to avoid wall wetting and lag issues. If that is the situation, then LPG should be OK. I seem to recall that 12:1 is common for natural aspirated engines.

Your LPG valves consume about 5A, which is more than the Frankenso was designed for. I tried to over build them, so it can probably handle it, but I would be concerned with heat. So I would suggest adding a heat sink or run the risk of them shutting down if they over heat. I would also suggest picking injector channels which allow for them to be as spread out as reasonably possible. Don't pick 4 driver chips that sit side by side.

kb1gtt, I started a fresh topic dedicated to the project since the current topic is in the "Welcome" section. You can see my answer on your questions here: http://rusefi.com/forum/viewtopic.php?f=3&t=1246

Thanks!