High speed ignition "miss"

[Morania]

I recently had a new engine put into my '87. At highway speeds, there is a intermittent timing miss. At street speeds, the miss occurs in higher revs. I just checked my injectors with a stethosope and they seem to be click right along in low and accellerated speeds. The mech who did the repower job couldn't find a problem that was obvious.
Now I'm hoping to bump into one of y'all who have had this problem before.
I don't know if this is related but, I had a bad thermostat running the engine cool and I wonder if the starting injector now has issues due to the lower temperatures messing with its normal operation.
Injectors ain't cheap. Hope there's help here.

 

[TSP-MIKE]

First check your spark plugs and see if they are gapped properly. Then i would check the timing to see if it's correct. Also try taking the compression reading from all the cylinders. It should be within 5% difference. You might be losing fuel at the higher RPM's, did you replace your fuel filter?

Mike

 

[Morania]

All that stuff checks out.

The engine renewal was the deluxe job with new "everything." He checked the nearest culprits like you mentioned during the 500 mile "How's it doing?" visit. Engine anaysis showed that stuff to be alright.
I've been wondering about the wiring. I've heard that the injector wires for the SE5's sometimes chafe and have to be seperated and rerouted. Legend?
I also haven't had the injectors bench tested at the dealer but with the noise test sounding alright, I kinda left it at that.

 

[TSP-MIKE]

Fuel pressure regulator, fuel pump?

 

[Morania]

Here's another addition to the symptoms

The miss only starts when the engine is good and hot. First thing in the morning, it runs smooth as silk.