I know this sounds wierd, but I'm now on LPG and need to know when the petrol injectors are cutting back in under load.

The system is set to switch back to petrol over 3000rpm AND with 15ms injection times. This means I can run 1 bar on LPG and then run 1.4 bar on petrol for safety reasons.

The problem I have is that I have no visual indication that the petrol injectors ARE cutting back in.

So can I wire a 12v LED to the injectors to see when they are working? And can anyone see a problem with this?

Cheers,

Wayne.

 

Anyone?

 

No, go via the solenoid.

 

What solenoid do you mean?

The only ones are the ones that switch on the supply from the tank and these are on when petrol cuts back in.

Wayne.

 

Who done your conversion out of interest?

 

DIY mate, kit from Tinley Tech LPG Equipment - LPG conversion kits, LPG advice, LPG parts

 

monitor injector duty on your pfc?

or does it cut injectors but pfc continues without knowing so is still displaying a duty?

which kit did you get, very interested to know how you get on

Simon

 

That's exactly the problem Simon!!

The PFC is still showing the duty as IT still thinks they are operating. When the kit is fitted, with the new gas ECU, it chops the negative wire to each injector and simply shuts them down.

So, some bright spark on the lpgforum has sugested fitting an LED with a 1000ohm resistor across one of the petrol injectors to indicate when they are working. I really don't know what the effect of doing this will be and I wouldn't want any sort of current drain making one pot run lean when on petrol.

The kit is the BiGas SGI S N with a double reducer, high flow injectors (they don't give anymore details than that), 80 litre tank (64 litres of gas at 80% legal fill rate), the ECU and the rest of the fittings. I used flexible pipe instead of copper for the route from the boot to underbonnet. There is no way the copper can go through/under the rear subframe etc.

I have been running 1 bar soley on gas with no increase in engine noise/knock. It does produce less power on gas, but not much. At the 1.4 -1.5 bar setting it cuts back to fuel as intended.

Economy wise, on a run petrol will give 25-26mpg and LPG gives 22-23mpg.

Still not bad at 54p a litre.

Wayne.

PS Tinley Tech LPG Equipment - LPG conversion kits, LPG advice, LPG parts

 

simple low watt bulb or led should be fine to check it but there must be an enabled output wire on the new setup?

very interested to see how you get on with it long term

 

Simon,

No output to anything at all. Even the change over/tank level switch has no indicator to tell you if this is happening. The only thing the ECU does is change over the injectors and thats it.

I will try an LED at a very low injection setting and see if the running changes at all.

I suppose a snooping circuit to detect the current flow may help.

So, you dont think an LED would sap too much power and harm anything? This is at 85% idc though.

As for long term use, I am now doing 300 mile per week overall. I am using flashlube to make sure that there is no valve seat issues, although if it runs on unleaded then LPG should have no effect.

Wayne.

 

Just to add that although the software can monitor this via the LPG ECU there is no way to log it. Unless you are very good at reading the screen while someone else is driving hard then its useless.

Wayne.