STALL AFTER START, STALL DURING DECEL, OR HES. COLD

MODELS AFFECTED: 1987 CIMARRONS

Some 1987 Cimarrons may stall under one or more of the following conditions:

- After start up on a cold engine - After start up on a warm engine - On deceleration

In addition, some 1987 Cimarrons equipped with manual transmissions may hesitate on acceleration cold. To repair these conditions, the following steps should be performed:

1. Check for vacuum leaks at the MAF sensor, PCV tube, and the EGR transfer tube.

2. Cplean the throttle body bore in the area behind the throttle plate to eliminate any accumulated residue. Refer to Serviceman Bulletin T-87-136, Group 6E for correct procedures.

3. Verify proper engine idle speed. Refer to Serviceman Bulletin T-87-136 for correct idle speed specifications.

4. Disconnect the negative battery cable.

NOTE: The negative battery cable must be disconnected for at least five minutes to clear the ECM memory to ensure proper idle speed.

5. Install revised MEM-CAL:

Service Service Emission Part MEM-CAL Broadeast System Transaxle Number I.D.* Code + ------ --------- ------ ---- ------ FED (AUTO) 1228533 8533 ADRY FED (M/T) 16120949 0949 ADSC CAL (AUTO) 1228534 8534 ADRZ CAL (M/T) 16120953 0953 ADSD

* ECM MEM-CAL I.D. can be read with a scan tool connected to the ALDL link. + Broadcast Code can be seen through the access hoIe on the top side of the MEN-CAL cover.

6. Reconnect the negative battery cable.

7. Start and idle vehicle in park (or neutral for manual transmission) for five minutes.

8. Turn air conditioning off and ensure the coolant temperature is between 800 C and 1070 C.

9. Block the wheels, apply the brake, and idle the vehicle in drive for one minute (for manual transmissions, leave the vehicle in neutral).

10. If a stall or hesitation condition still persists, refer to:

- Bulletin 88-74, Group 6D "Misdiagnosis of the Direct Ignition System (DIS)". - Bulletin 88-9,Group 6D, "Engine Miss, Backfire, Hard Start, Hesitation, or Stall". - Section 6E3-B of the Service Information Manual.

For warranty purposes, use Labor Operation T6280 at 1.2 hours.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.