Hi I hope it okay to post this here not sure if I should post in after market products or engine problems

I'm over the pond in the UK
I have an RV with a Ford Triton V10 6.8 engine fitted running on the F53 chassis.

Due to the high cost of petrol ( £6.75 / $8.68 a gallon.) I've had LPG fitted, since fitting she now on occasions when approaching roundabouts or junctions after a good run she will die on me the engine runs so quietly that the first thing I know about it is I loose power steering not fun when entering a roundabout so have to select N and restart. Then she will run fine once more....

I was reading about the fuel pump relay and IAC being the problem for this... in an old thread here..... https://www.ford-trucks.com/forums/489399-v10-stalls-no-warning-2.html

Don't think it's IAC or fuel intake as I've since had a completely new throttle assembly fitted as the throttle motor sensor magnets came away from the motors body and couldn't be repaired.

Sometimes the engine light will come on with engine running lean on banks 1 and 2 and fuel pump failure, which again would be because the fuel pump is switched off while LPG is running.....

Someone else I know of has only just had LPG fitted by a completely different company and he now has the very same problem. Except he is getting codes saying he's running rich.

Now just wondering if the ECU is getting confused by the mixed up readings from the Lamba sensors and is trying to compensate but can't as petrol is all switched off while running on LPG. (Propane)

 

The the ECU codes say it "running lean"(But in reality it doesn't mean it is.) it's because the Co2 levels are much, MUCH lower, running on LPG not that it's actually burning lean in the cylinders, gas is a cleaner fuel the Lamba sensors just think it's running lean..... it's kind of like just unplugging sensors.

Not sure there's even a work around to fooling the ECU that the readings are correct..
I'm sure this is what the problem is.......

ECU has a hissy fit ,say's "**** it I give up I'm shutting down", you restart engine and it all resets....

I think the only way to fool it would be to unplug the sensor and fit a correct value resistor in place of it to send the correct voltage back to the ECU so it thinks the Co2 levels are correct.

Think I will turn the Auto-gas off and run on petrol this weekend a 200 mile round trip and see how she runs .
Will do the engine good to get a taste of the good stuff... don't want it getting addicted to LPG........