Relay 1 and 2 are EGI relays. 1 supplys power to the ignition coils and the other supplys power to the ecm, Speed sensor unit and lpg injector drive unit... If im looking at the correct schematic that is.

Sorry. Terminology is my weak point. The solenoid & filter is what I meant. And drained the vaporizer. I was trying to confirm that fuel was traveling. Do you happen to know what those two relays are that are below the battery? (No wiring schematic.) I'm about to trace the wiring but I'm guessing they will go to the ECM & I still won't know what they are. I have not checked anything with injector so that is probably my next stop. At least until I get my hands on a schematic. Thanks for your input!

Little confused as to your terminology when said changed regulator and checked vaporizer drain as the LP regulator and vapourizer are the same.

You should be able to find an OBD2 connector on the LH side near the battery under the hood that a common automotive code reader can hook up to.

Besides pulling codes there lots of basics you havnt mentioned like check fuses in fuse box, check inline fuse in the injector harness on the throttle body, check relays next to the battery especially relay 1 and 2, check for spark with a tester. Check vapourizer pressure (4.5psi to 6.5psi). Check for lpg leakage into intake (broken injector o ring or stuck assistant injector.) Check lpg pressure sensor and harness/connector in throttle body, Check compression, check for vacuum leaks.

Ive also seen a few harnesses rub through near the ECM connector that ended up breaking several wires.

Really you have to narrow it down more as to what your missing. Like is there no spark or no fuel.

Your assumption is correct. K21

I cant remember but is this the K21/K25 or the H20/H25 engine?

Im assuming its a K21 because you said ECU and Cam and Crank.