Romano Ris changing over only when connected to a computer

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nickevans · #1 Post by **nickevans** » Mon Nov 26, 2007 10:33 pm

I still cannot believe it but it is fact that my Romano RIS has developed a habit of switching over to gas only when plugged to a laptop. It doesn’t mater whether the Romano software is installed or not on the computer, whether the software is running or not, as soon as the gas CPU sniffs a switched computer that is powered by the car on the other end of the cable it has no problem switching to gas (10 out of 10). As soon as I disconnect (or shut down) the computer it refuses to switch over to gas. If it has switched to gas when connected with a laptop it will stay on gas (and work properly) until next time I start the car. Tried many things – changing settings for the temperature, switch RPM, disabling diagnostics in the software, removing the fuse (many times), resetting the errors from the software, moving cables and connectors but still the same.

RPM signal is picked up OK and displayed as it should be in the software. There is no pressure sensing and no level sensing and whet it goes to gas the yellow LED is not flashing.

Is it hardware fault of gas ECU?

I also noticed that the computer must be powered by adapter from the car. If it runs on its our battery the gas ECU will not change over to gas.

Some simple measuments show that by powering the laptop by this adaptor I raise the common signal ground level in the RS232 cable with 0.5 volts compared to running on battery only but can this be causing the gas ECU to change over properly?

I double checked all cables for loose connections measured the ground taken by the gas ECU.

Has anybody seen such a thing or even knows how to cure it. Any suggestions welcomed.

Since I am running out of ideas I will have to drive with a laptop all the time – not good

supercharged_buddy · Tue Nov 27, 2007 10:35 am

my car has a similar quirk with its DREAM XXI system. It'll only change from gas to back petrol at 4000rpm (like its ment to) when the cable is connected to the gas ecu..... disconected it just misfires.

go_lpg · #3 Post by **go_lpg** » Tue Nov 27, 2007 11:47 pm

Nick,

make sure the HT leads are not too close to the RPM wire (or vice versa).

Ring Colin at AGWW - 0870 746 1262. He might have heard this one before - Interesting and a little awkward dragging the laptop everwhere.
I'd like to hear what the cure is.

Regards

Steve

www.go-lpg.co.uk

brianm · #4 Post by **brianm** » Sat Dec 01, 2007 12:24 am

Earthing fault! The laptop and leads are providing an extra earth path.

supercharged_buddy · Sun Dec 02, 2007 11:24 am

rossko, thats pretty much it, the gas system cant keep up with the engines thirsty fuel demands. Even if i have the system set to gas at high rpm, without the data cable connected it misfires at around 4500rpm onwards, with the cable connected it flicks itself back to petrol untill the revs drop. cable doesnt have to be attached to the laptop just plugged into the gas system which makes brianm's earthing problem theory most likely.

I'll let you know what firmware version is on the OMVL ecu when i find my adapter plug for the laptop.....

rickyboy · #6 Post by **rickyboy** » Sat Dec 22, 2007 12:17 am

Just a thought, are you using a serial to usb connector? It may be possible (this is just a theory) that if you are using one of these connectors that your bios has usb power turned on and is causing the problems. The ecu will provide the power so mabye try turning that option off in the bios if applicable. As I say this is just a theory so don't slate me if this is a nonsense.