Hi,

I have an EB2 I6. It has a duel fuel setup on it. Now, I know that when on petrol when in closed loop it should run at fuel ratio of 14.7/1. I know that when on LPG the LPG fuel ratio is richer because of the way LPG burns. Would it be possible that the system is only designed run at one mixture. The reason I ask is that when ever I run on petrol it smells rich even at operating temp. You can sit at the lights and smell the rich exhaust smell if you have the window down. It doesn't blow smoke as I had my misses give it a bit of a blast while folowing behind her in my second car. So it is not running on cold mixture but it is definatly richer than it should be on petrol. The trip computer returns about 17L/100Ks around town and that is taking it pretty easy. A mate of mine has a EA multi point and his doesn't have the exhaust smell but returns about 15L/100Ks. Not much different. Do the manufacturer only set it up to run properly on one type of fuel but still make it capable of running on both??? The gas system is about 10 years old but has a type of piggy back computer called "Electronic feedback system". I am thinking that it might fool the cars O2 sensor input enabling it to use the O2 sensor on gas. Does this make sense?

dude there generally can be some other issues mwhen a car is converted to duel fuel but generally the factory ecu will control the air fuel ratio through the map sensor and no the gas computer wouldnt do anything with the o2 sensor as that will only work with fuel and most of the duel fuel gas systems are tuned and adjusted manually as for your running rich i would be more inclined to look at the injectors as sometimes if cars are run more on gas the injectors tend to build up carbon alot more and can run a bit s**t other than that it could be a dodgy o2 sensor or just si,ple excessive carbon build up on the throttle body and pistons

With most older aftermarket LPG dual fuel systems, they were a compromise and often resulted in one or both fuels not running to optimum settings, so power was compromised.

Systems of that age usually had a little box which connects to the LPG switch, alternator, coil, gas cutout valves, injector cutout and little else. They were not much more than a safety cutout for the LPG system.

There were some LPG systems that used a box that was connected to the O2 sensor and contained a solenoid that controlled a vacumm signal from the throttle body to the gas converter. This had the effect of controlling the amount of LPG into the motor and thus the mixture. I think it was an called 'aurtonics 4046'. Supposedly a bugger to set up but magic when done so properly

As i'm not familiar with the EB's, i won't suggest what to do w.r.t. servicing other than to say run it on petrol frequently. With more info on your problem, others may be able to better help.

Cheers

Ok, I had a look at what wiring was cut into for the gas instalation. The green wire that is one of the O2 signal wires has been cut and runs into the little box under the bonet that is that electonic feedback system and then it returns back via another wire to the other side of the cut O2 wire. I havn't used gas for while as there are problems with it and it is not economical to repair. I disconected the electonic feedback system from the O2 wiring and rejoined the original wire. Went for a drive across town and sweet ...fixed. The trip returned 14.3L/100ks. Better that ever before. The rich smell at idle has gone and she runs a bit smoother. Thank god for that. At a dollar + per litre it will save me a bucket load..

Good to hear that it runs better on petrol.

It could just be a problem with your LPG control box and if you fix that and tune the LPG system, you may be rather happy with the cheeper LPG fuel.

So who makes the LPG control box and LPG converter ?
Out of interest, what do they want to fix it as you say it's uneconomical to repair ?

Cheers.