[GregWeld]

Rich,

Okay -- Jody will correct me on this... but there is no reason at all to have the vacuum reference on the fuel regulator. That application is only for boost reference. But - if it was tuned with the vac applied - it should be okay. There's just no reason to have it. However, DO NOT plug the vacuum port of the regulator. It needs to be open to atmosphere.

I've been told that the IAT (Intake Air Temps) have very little to do with the actual references used in the ECU... I've been told this by at least 3 different tuners... but then - they could all be wrong too. Since I have 8 stack EFI - my IAT sensor is just kind of "hanging" between a couple of the stacks back at the rear of the engine. I've put it in a couple of places - and it doesn't seem to make any difference in anything.

Since your 'issue' seems to be so intermittent... I think I might be looking for an electrical draw. Maybe the voltage drops when something goes on? Causing a momentary blip in the ECU/sensor voltages.

I'd also be looking for a possible "hole" in the VE or A/F map - where your foot (TPS or MAP) just drops into this hole. If you have 3D visual on your system - look to see the junction at the perceived RPMs/Map signal (like 2200 rpm and 45kpa -- or wherever you think this fault happens) and see if there is a dip in the map or a "mountain" right around there...

Last thing I can come up with to check on - the voltage to the Fuel pump... I'm assuming you're running it off a relay.... and that it has a great ground system... and that it's not dropping voltage momentarily when your fans kick on - or the stereo kicks on - or the A/C compressor goes on etc.

I'm assuming also that you're using a ONE WIRE type alternator charging system (with no points style voltage regulator in the system) and that the alternator is capable of handling the total loads placed on it (i.e., the amp draw has been added up for all your systems and that the alternator is capable of supporting them all).

LAST... there has been some discussion about faulty MSD systems. Can't remember where this thread was - but there was an issue with them heating up and breaking down. One guy was icing his down for awhile until he sent it back for a factory look see... I just don't remember the issue or the outcome.