Firstly when changing over to gas in the early hours it can sometimes missfire for a few seconds, it then clears and runs fine. If I buy a programming lead and software could I alter the changeover temperature to eliminate this ?
Secondly I found that the catalytic converter has been removed, probably due to the lambda sensor being shot. I have replaced the lambda sensor for a genuine Audi item, it does run a little sweeter but I am now getting 2 errors on the VAG diagnostic tool, Lambda sensor shorted to positive and Lamda sesnor lower stop limit.
You don't need the cat if the car is run on gas. If you take it for an MoT running on petrol without the cat, it will probably fail but if it is presented for test running on gas, it should pass no problem. The errors may be due to the way the connection to the lambda has been made. There are two ways of making the connection, you either T into the signal wire or you cut it and intercept it. The gas ECU then sends a simulated lambda signal to the petrol ECU. This can often cause lambda errors to be thrown up by the petrol ECU. Simply Teeing into the lambda signal wire should cure this.
I've had a look at the wiring and I think my 3 year old daughter could've done a neater job, bare wires twisted together and held with tape, 6 miles of loom when 2 feet would've sufficed etc etc. Is there a wiring schematic for this unit available to download ?
The Zavoli uses an AEB ECU as does the OMVL Dream, this link http://www.vogelsautogas.nl/documenten/ ... eiding.pdf
is for the OMVL version in Dutch, the Zavoli manual (without a wiring diagram) is here http://www.zavoli.com/upload/manuali/en_file_7.pdf
or if you look at the third post in this thread on page 4 viewtopic.php?f=33&t=8148&start=45
you'll find the OMVL diagram but annotated in English.
Finally, should i really have 2 lambda sensors ? one for petrol and a seperate for gas or is it ok to splice the signal from 1 sensor to both ECU's as it's set up now ?
As your lambda sensor is a standard 4 wire Zirconia sensor a second one isn't necessary. What you have will work perfectly with the gas system.