Part 1 of 2

Chart A-3 (Part 1 Of 2):

HEI Circuit Detail:

DESCRIPTION:

All internal combustion engines requires spark, fuel, air, and proper timing to operate. The PFI system is no different. If the battery is at the proper charge level, the first step should be to determine which of these elements is missing.

NOTES ON FAULT TREE:

1. Checking for codes stored and for proper "SERVICE NOW" or "SERVICE SOON" operation. Repair stored codes and improper telltale operation before proceding with CHART A-3.

2. Checking for spark.

NOTE: Use and ST 125 to test. A spark plug with a wide gap or allowing a plug wire to arc to ground may not test the HEI for sufficient output and may damage the coil, cap or rotor.

3. Fuel pressure should be between 40 and 50 psi at key "ON," engine "OFF." With the engine running, fuel pressure should be 32-38 psi and vary with engine load (MAP). If pressure does not vary or remains high, check for vacuum hose disconnected from pressure regulator.

5. Checking for fuel pressure regulator causing fuel pressure to drop off. If pressure holds with the return line capped off, replace fuel pressure regulator.