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PROM - Cold Engine Start/Stall/Surge in Gear: Overview

FILE IN SECTION: 6E - Engine Fuel & Emission

BULLETIN NO.: 57-65-30

DATE: February, 1996

SUBJECT:
Cold Engine Start and Stall, Closed Throttle Idle Surge in Gear (Install A.I.R. Kit, Flash Prom and Three Way Catalytic Converter)

MODELS:
1994-95 Chevrolet Camaro
1994-95 Pontiac Firebird
with 3.4L Pushrod V6 Engine (VIN S - RPO L32) and
Automatic Transmission RPO MD8)

CONDITION
Some owners may comment that their vehicle starts and stalls on the initial cold start of the day. Others may comment on a closed throttle idle surge when the vehicle is in gear. This usually occurs in a parking lot slow driving/idling around a parking lot maneuver. Both conditions typically occur in a 68-89° F ambient temperature range.

CAUSE
Due to variation in individual components and gasolines available it is possible to have a powertrain that, when these things are stacked together, performs temporarily in a lean mode and creates the conditions described above.

CORRECTION








To address this temporary lean running condition during warm up, a new flash calibration has been developed. This new calibration richens the open-loop air/fuel ratio at 20° C to 32° C range (68° F - 89° F). To ensure compliance with Federally mandated emission levels, an A.I.R.. (air injection reaction) kit has been developed along with a new three way catalytic converter. If, after exhausting normal diagnostic procedures, it is determined that the A.I.R. kit along with the calibration is necessary to correct the vehicle, the following procedure should be used to install the A.I.R.. kit. Figures 1 and 2 are a pictorial of the parts installed in the kit.

Remove or Disconnect

1. Battery negative cable

2. Cross car air inlet duct

3. Suitably support vehicle and raise

4. Exhaust pipe bolts at exhaust pipe to three way catalytic converter flange

5. Exhaust crossover pipe nuts

6. Converter hanger bolts

7. Exhaust crossover pipe assembly from studs on exhaust manifolds

8. Lower exhaust system

9. A/C compressor rear bracket bolts to cylinder block

10. Rear two right exhaust manifold bolts

11. Lower vehicle

12. Accessory drive belt

13. Oxygen sensor connector

14. Generator positive cable

15. Electrical connectors from generator

16. Generator rear brace ("S" brace)

17. Generator assembly

18. A/C compressor from front bracket and reposition

19. Generator "Y" brace

20. # 1 spark plug wire

21. EGR electrical connector, EGR adapter and flex pipe

22. Right exhaust manifold front and middle bolts

23. Right exhaust manifold assembly, heat shields and gaskets

Install

1. Transfer oxygen sensor from old manifold and re-install using new oxygen sensor gasket, tighten sensor to 42 N.m (31 lb ft)

2. Exhaust manifold gasket

3. Exhaust manifold assembly and heat shields

Important:
Rear shield must be in place when installing manifold. The rear shield can be held in place by momentarily installing the EGR adapter stud and nut.

4. Right exhaust manifold bolts/screws, tighten to 25 N.m (18 lb ft)

5. Place baffle in right exhaust manifold A.I.R.. pipe hole. Install EGR adapter and flex pipe, tighten adapter stud and bolt to 26 N.m (19 lb ft), tighten flex pipe to inlet manifold bolts to 26 N.m (19 lb ft).

6. Route A.I.R. pipe behind engine and between engine and transmission fill tube, tighten pipe nut

7. A/C compressor to bracket, tighten bolts to 50 N.m (37 lb ft)

8. Generator "Y" brace, tighten bolts at generator to 50 N.m (37 lb ft)

9. Generator rear (S) brace, tighten nut at generator to 50 N.m (37 lb ft), nut at EGR adapter stud to 25 N.m (18 lb ft), tighten long bolt/nut at generator pivot to 50 N.m (37 lb ft).

10. Electrical connectors at generator

11. Positive cable at generator

12. Oxygen sensor electrical connector

13. Accessory drive belt

14. Secondary air injection pipe, secure with 1 bolt, P/N 11515763, at left cylinder head, tighten bolt to 50 N.m (37 lb ft).

15. Check valve to secondary air injection pipe assembly, tighten to 19 N.m (14 lb ft).

16. 90° check valve hose from check valve to secondary air injection check valve pipe bracket with clamps

17. Remove left exhaust manifold top center position bolt and install stud P/N 10191776, tighten to 25 N.m (18 lb ft).

18. Secondary air injection check valve pipe bracket to stud, install nut, 11514518, tighten to 25 N.m (18 lb ft).

19. Cross car air inlet duct

20. Locate electrical connector for air pump typically tucked up near the relay and fuse center on the left front fender well, route the harness to the air pump location next to the stepper motor cruise motor on the left front frame rail

21. Suitably support and raise vehicle

22. Tighten rear manifold bolts to 25 N.m (18 lb ft).

23. Rear A/C compressor brace to engine bolts, tighten to 50 N.m (37 lb ft).

24. Install new three way catalytic converter to exhaust "Y" pipe, tighten clamp to 68 N.m (50 lb ft).

25. Raise cross over pipe with converter into position, install exhaust hanger to converter, tighten bolts to 41 N.m (30 lb ft).

26. Y pipe with seals to exhaust manifold, tighten nuts evenly to 35 N.m (26 lb ft).

27. Tighten converter flange to exhaust pipe bolts to 20 N.m (15 lb ft).

28. Remove 2 bolts from stepper motor cruise bracket, install 2 new studs, P/N 10186163.

29. Install air pump bracket using 2 nuts, P/N 11505005. Use 1 bolt, P/N 10222298.

30. Air pump to bracket, using 3 bolts P/N 11513677, tighten to 12 N.m (9 lb ft).

31. Secondary air injection pump hose and secondary air injection pump air cleaner hose, secure with 2 clamps to air pump.

32. Electrical connector to air pump

33. Lower vehicle

34. Connect air hose from pump to cross car duct, secure with 1 clamp

35. Connect hose from air pump to air pipe at manifold. Secure with 1 clamp.

36. Battery negative cable

37. Install new flash calibration

38. Install new emission label (see chart for correct label application)

39. Start engine and check for leaks