You may not get 20 mpg again after the new engine is in there.
The biggest improvement I read before was changing the Differential gear ratio.
That got nothing to do with the engine itself.
Here is the bottom line.
Does it have pressure when the truck runs? If yes, the prime before start duration really does not matter.
The problem is in 94-95 trucks when the LP is run by OPS when engine is running.
In this case, the Relay mod will be very important because there is really not...
Flight System is good.
Make sure PMD is on a heatsink even if you are just testing it.
The stock cable under the intake can go bad also.
Make sure the fuel system is operational like Lift Pump, Filter, etc.
Load test the batteries one at a time.
Make sure all grounds are good, connectors are...
The PMD ground, is it still attached to the IP? Not to the heatsink.
I am assuming the PMD is on a heatsink.
How long is the PMD mounted on the intake?
Somebody at the other forum suggested this tool.
It has the capability of Tech II.
https://www.amazon.com/dp/B01NACTAY8/?coliid=I30ERCCUNWLN6P&colid=288N17OIKZKLH&psc=1&ref_=lv_ov_lig_dp_it
I am just passing on the information.
I have never used it since mine is a 95.
KOKO is not something that you do for the heck of it, there needs to be a reason.
There was another thread on this a while back.
Not sure if the poster ever come back or resolve the problem.