Hey everyone!! Need some advice with my jeep. This has been an ongoing project for a while and I'm getting so close to having her running but it just seems to be one thing after another.

I have a 96 XJ Ltd that i have converted to LPG and i was taking her to be certified and she broke down half way there. No rough running she just cut out. She hasn't been used at all except for engine runs over the last two years and she just cut out after driving for about 20 mins. We got her off the road, left her for about half an hour to cool down and no restart. Called roadside assistance which arrived about 3hrs later and she started perfectly, typical. Got her home without issue.
Previously, she was brought back from a friend doing some work on her. Temp gauge was all over the place (now sorted) and so he opened the rad cap, coolant everywhere. Wouldn't start for a couple hours after that. I think the coolant shower is unrelated however shows that when she gets hot she doesn't like to play ball with starting.

As I've mentioned i have converted her to LPG which has required various rewiring. I had tapped into wires leading back to the ECU. Wires i have tapped into are - Lamda probe, TPS sensor, Tacho, Switched Ignition, battery and grounds. I also have an emulator for the fuel injectors.

Now all of this could somehow be the cause however from what i have read this is common issue with these XJ's so what i have heard so far that could be the potential problem is......
CPS Sensor?
TPS Sensor?
Grounds?
ECU Screws being too long?

Before i start doing the work to find this issue and start spending cash that doesn't need to be spent i want to put it out to all you XJ geniuses and try figure out the best way to start (the cheapest way to start). Im learning more and more with this jeep that blood sweat and tears have literally been shed over and i just want it working for gods sake but i am no mechanic.

Any help that you can offer will be greatly appreciated and hopefully we can get this girl running. Ive put a lot of love into this jeep and I'm so close to getting her where i want her to be!!

Thanks in advance everyone.

Any questions about what i have done to her, the lpg just ask away!!!

Sean