Engine - Hard Cold Start Diagnostic Procedures
Number 84-6 (Gasoline)-37 Date 5/84Subject: DIAGNOSTIC PROCEDURES FOR COLD START CONDITIONS ON 1983-1984 PONTIAC 4-CYLINDER 1.8L AND 2.5L ENGINES (ENGINE CODES O AND R)
The following items should be checked when encountering a comment of hard starting on Pontiac produced 4-cylinder engines at 0~ F (32~C) and below ambients.
1. Engine spark plug application should be:
1.8 OHC - R44X LS - .035" gap 2.5 EFI - R43TSX - .060" gap
2. Engine should be serviced with 5W-30 low friction energy conserving oil. GM Goodwrench oil is one possible source for this oil.
3. Battery must be at least 80% state of charge.
4. Check for stored codes. Replace any components indicated by code. Check connectors.
5. Check for proper operation of fuel pump relay. Also verify proper operation of fuel pump check valve.
6. Fuel pressure should be between 9-13 p.s.i. (62-90 kPa) with the engine running.
7. Check coolant sensor (open sensor will cause excessive fuel delivery on cranking, shorted sensor will result in lean condition).
8. Perform HEI system check (refer to bulletin 83-I-28 and 1984 Service Manual Sections 6D, 6E2 and 6E3).
9. Generator capable of producing at least 95% of rated output.
10. Inspect fuel for contamination.
11. Check operation of block heater (if equipped).
All the above items are important for the proper starting of these engines at ambients as low as -20~ F (-36~ C).