asthmatic 3.9 efi needss help please.well hello again, four years older and beset with another hiccup which confuses this 75 year old's brain, your co

well hello again, four years older and beset with another hiccup which confuses this 75 year old's brain, your collective knowledge would be greatly appreciated.
The Lotus Excel hasn't been used much due to my illnesses but I am now getting back into it with renewed enthusiasm. I had the 14CUX reprogrammed with an EPROM similar to TVR and fair to say , it accelerates like "brown stuff off a stick" but here's the rub.
When the engine is hot it develops a total momentary cut out/stall at around half throttle...very dangerous in an overtake or pulling out into traffic.If I accelerate hard, back off perhaps for a tight bend, and then immediately back on throttle it shuts down for a second and then comes back in fine until the next throttle back when we go through the same scenario again ad infinitum.
Done all basic checks for loose wires etc., but nothing obvious. Thanks in advance.

The above is my post from December 22, although it is an old post I have copied/pasted to save having to write all over again.
The car went out on a motor club run around North Somerset last Sunday and exhibited the above same fault several times over. All I can add is that it occurs under load and around 2000 rpm...like it takes a huge gasp of air but no fuel. This is momentary and by stopping and letting engine cool down for 15 minutes it starts instantly, drives beautifully but once hot it occurs again. No obvious clues apparent so I'm hoping that one of you knowledgeable Landy people can point me in the right direction.

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This could be due to a number of issues:

1. overheating/fuel evaporation combined with fuel volume/pressure when most needed. Do you have a heatshield between the base of the plenum and the inlet manifold?
2. fuel volume and pressure - are these correct for new 14CUX EPROM fuel map?
3. where did you buy the new EPROM from? It may be you need uprated Bosch injectors to match peak fuel demand.
4. What ignition set up are you running and do you have the correct ignition amplifier to match ignition advance to new fuel map?
5. Have you checked the fuel filers of of correct size for peak fuel supply - suggest high volume Bosch canister unit between tank and pump, Filter King with adjustable pressure regulator in engine bay.
6. Are the fuel lines of correct csa for new fuel map AND can handle the pipe vacuum under full load - here the problem could be the flexible fuel collapsing under peak load. Suggest replacing with modern hardline flexible lines.
7. Are you still running the std Hitachi MAF - if so, when did you last clean out the MAF?
8. Throttle Pot Sensor - should you have upgraded the TPS to the later adjustable unit as they may be needed with the newer fuel map. + is the TPS carbon clear and correctly positioned at install?
9. Of course, this could be a simple ignition breakdown at peak current load :. suggest running Magnecor KV85 ignition leads + correct NJK spark plugs + high output coil for max' spark.

With these issues I'd suggest you talk with Mark Adams at Tornado Systems? Make any recommended changes and then get the car set properly on a rolling road by people who know the 3.9 with modified 14CUX. Mark used to team up with a very good rolling road tuning specialist in Gloucestershire.