ENGINE INTERMITTENT STALLING NEW PROM PART NUMBER

MODELS/YEARS: SOME 1986 CUTLASS CIERA, DELTA 88, NINETY-EIGHT AND TORONADO MODELS EQUIPPED WITH 3.8L SFI ENGINES (VIN CODES 3 AND B)

NOTICE: This bulletin supersedes Bulletin 86-T-62A. Please discard 86-T-62A and replace it with this revision which provides updated service procedures and service PROM pan numbers.

Some 1986 vehicles equipped with 3.8L SFI engines (VIN Codes 3 and B) may experience an intermittent condition where the engine may occesionally not stay running on deceleration or during parking lot maneuvers under closed throttle conditions.

If the condition is experienced on a vehicle whom the basic orgins, controls and systems are performing properly, and cannot be repaired by using currently published service and diagnostic procedures, it may be necessary to install a new service PROM which has replaced the obsolete service kit.

Effective August 31, 1987, the four components involved in service kits 25531123 through 25531129 referenced in bulletin 86-T-62A, should only be replaced individually as necessary, and labor operation number T5123 will be invalid.

NOTICE: Any warranty claims submitted using T5123 after August 31, 1987, will be rejected.

All service kits currently existing in dealership inventories should be disassembled and the parts returned to dealer stock and used for service replacements. in the near future, General Motor Service Parts Organization (GMSPO) will issue an information bulletin authorizing return of "Kit PROM's" to the local parts distribution centers.

Listed below are the revised service procedures and service PROM part numbers for an intermittently "Won't Stay Running" condition:

1. After it has been determined that the basic engine, engine controls and systems are performing properly, replace the PROM.

2. Remove the air intake duct from the throttle body. Clean the PCV residue from the throttle body bore in the area behind the throttle plate, using a shop towel with "GM Top Engine Cleaner" (Part number 1052626) or "AC-Delco Carburator Tune-Up Conditioner" (Part number X66-P) or equivalent product that doesn't contain methyl othyl ketone. It should be noted that what appears to be just a small amount of PCV residue accumulation can be enough to limit air flow, and result in an inaccurate minimum air rate adjustment.

3. Reinstall the air intake duct and check the minimum air rate and adjust, if necessary, to 500 rpm using the following procedure:

a. After the engine has reached normal operating temperature, turn the engine off and ground the diagnostic test terminals of the ALDL connector.

b. Turn on the ignition, but do not start the engine. Wait at lease 3O seconds.

c. With the ignition "on", disconnect the IAC motor electrical connector.

d. Remove the ground from the ALDL connector and start the engine with A/C off.

e. If necessary, remove the cap from adjusting screw and adjust engine to 500 rpm while vehicle is in drive and A/C is off.

f. Turn ignition "off" and reconnect connector at IAC motor.

4. Adjust throttle position sensor to .40-.44 volts. Do not exceed .44 volts.

SERVICE PROM PART NUMBERS

Axle Sales Code Model I.D. Located On Scanner PROM I.D. If Service Application Axle Deck Lid Decal This PROM is Installed Part Number ----------- ---- --------------- ---------------------- -----------

Cutlass Ciera All N/A 8591 1228591 Ninety-Eight 2.84 F17 8592 1228592 Ninety-Eight 2.97 F79 8593 1228593 Delta 88 2.84 F17 8594 1228594 Delta 88 2.73 FP3 8595 1228595 Toronado 2.84 F17 8620 1228620 Toronado 2.97 F79 8621 1228621

WARRANTY INFORMATION

Labor Operation: T5147 Labor Hours: .7 hour Trouble Code: 92

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.