What exactly does the control unit do? My haynes manual does not make this clear

It probably means the ECU (Electronic Control Unit) for the Fuel Injection system. This is the "brain" of the FI, and controls when the injectors open and how long they are open.

--DD

Is there someone that rebuilds the ECU?? I was looking over some of the stats on Brad Anders site and noticed that no other ECU's were compatable with the 75-76 CU16X ECU. Might no be a bad idea to have a spare one availbable.

They are not a part that usually fails.

My '76 has 300k on the clock and has the original ecu. Not so with the rest: 2 mps's, 2 head temp sensors, 2 injectors, 2 aux air valves. First time I replaced a mps it was $220 new - not no mo - now > $1100. I got a spare one of those from
perf. Prod. Gave it a test drive - works fine. They get them from Ottos.

I heard talk that someone is rebuilding the MPS units in So. Cal.

If so, who and how much?

pardon - the spare I got is a rebuilt - around $200 - works fine. Ottos is in So Cal. IIRC Bander's (sp. ?) site cites a rebuilder but they dont sell direct to public.

Bret is the company that rebuilds them. They use a diaphram that is not as good as the original. Let Bleyseng build you one as he takes good diaphrams and re-calibrates them...