Don,
Hang in there.
Based on what you say in your email, I would look
very closely at fuel delivery. If your pumps are squealing, they are
sucking air, or you have vapor lock. The fuel is what lubes and cools the pump.
If there is no fuel flowing they overheat. Check for pinched lines, clogged
filters, loose/bad fittings on the suction side. Also, just having the pump
uphill from the tanks as little a 12 in can cause this problem. You need
good gravity feed to the pump and an adequate low restriction line. Pumps
are good at pushing fuel, but terrible at sucking it. These problems are
more common with high volatility winter blends of fuel.
Verify that there are no air bubbles in the pump
discharge with a clear line.
Bubbles in the line, of air, or fuel vapor will
cause the engine to lean out irregularly which will cause bucking, and
stumbling. There is no way you will be able to tune the motor if this is the
problem.
EFI pumps work best in the tank or at least with
gravity feeding fuel to them.
Good luck,
Monty
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