Id start by cleaning the battery terminals and cable connections carefully, a great many problems blamed on battery's and fuses are basically high resistance or intermittent connections, then use a multi meter to see what your dealing with
the first step is to use your inductive timing light to determine if you have spark at the plugs and your v.o.m. meter to see if the battery's producing over 13 volts when its hot, it may not be even ignition related? did you verify you have spark at the plugs? ignition spark should be bright blue and impressive, if its, weak,narrow, yellow or red theres a problem so research the cause, verify the coil and voltage
first check your shop manual for the fuse and fuse able link locations
fuses are located in several locations and fuse-able links near the battery
how about good fuel pressure?
if your running an HEI ignition that's occasionally caused by a bad module.
http://www.angelfire.com/empire/automot ... andtesting
http://www.aa1car.com/library/us1296.htm
Easy tests for HEI system:
1. Test for power at the pink BAT terminal. You should have battery voltage w/ the key in the start and RUN positions.
2. Connect the ground side of your test lamp to the battery POSITIVE cable. Probe the TACH terminal on the dist. cap while a helper attempts to start the engine. The test lamp should blink repeatedly as the engine cranks. No blink= bad module or pickup coil. Further testing is required to pinpoint the problem. Blink but no spark = bad ignition coil.
3. Remove the cap & rotor. Remove the green & white leads from the module. Connect your ohmmeter to the green & white leads. You should have approx. 800-1500 ohms depending on the ambient temperature. Open circuit (infinite ohms) = bad pickup coil.
Wiggle the green & white leads as you test. Ohm reading should remain constant if the leads are good. If the reading varies as the leads are wiggled, the pickup coil is bad. You'll often find broken pickup coil leads this way.
4. DVOM (meter) still connected to green & white leads. Set your DVOM to AC VOLTS. Have a helper crank the engine as you watch the AC VOLTS reading. A good pickup coil will produce about 3V AC when cranking. Less than approx. 2V AC indicates a bad pickup coil.
I really need more info, that could also be a carburetor or fuel system problem.
did you use the dielectric tune up grease under the module... it is heat sink grease that allows the transfer of heat from the module to the aluminum housing... without out this proper grease the module will overheat and burn out...
http://www.dimequarterly.tierranet.com/ ... h_hei.html
viewtopic.php?f=50&t=609
http://www.chevyhiperformance.com/techa ... index.html
http://www.bronco.com/cms/node/25
http://www.db-starter-alternator.com/St ... %20Motors/
viewtopic.php?f=44&t=773&p=1123#p1123
http://www.442.com/oldsfaq/ofign.htm
http://www.ehow.com/how-does_4809570_tr ... butor.html
http://www.aa1car.com/library/2003/us80312.htm
http://arrc.epnet.com/autoapp/9110/9110 ... System.htm
http://www.chevelles.com/techref/ftecref5.html
wet, loose, or broken electrical connectors or corrosion on connectors, is also possibly a cause of intermittent problems