HARD START, EXTENDED CRANK AFTER HOT OR COLD SOAK

MODELS AFFECTED: ALL 1985-87 CIMARRONS EQUIPPED WITH 2.8L V-6 ENGINE

Some 1985-1987 Cimarrons equipped with the 2.8L V-6 engine may experience a hard start condition after a hot soak (2 or more hours) or cold soak (overnight). This condition may be injector related, and should be diagnosed as follows:

1. Attach a fuel pressure gauge to the engine.

2. Restrict the fuel feed and the fuel return lines right after turning the engine off.

3. If the fuel pressure leaks down with the fuel feed and fuel return lines restricted, proceed to step 4. If the pressure does not leak down, refer to Serviceman Bulletin T-86-43, Extended Engine Cranking Time and/or Vehicle Does Not Maintain Fuel Rail Pressure, in Group 6C.

4. Follow Serviceman Bulletin T-86-54, Cleaning of Port Fuel Injectors, in Group 6C.

5. If the condition is still present do an injector balance test as described in chart C-2A, Section 6E3 of the Service Information Manual. Replace any injectors out of specification.

NOTE: Two types of injectors are used in the 2.8L V-6 engine. They are the Bosch injector (black in color) and the Rochester-Multec injector (half black and half silver in color) see Figure 1.

1985-1986 Cimarrons: Use the Bosch injector, P/N 17111297, or the Rochester-Multec injector, P/N 17111661, interchangeably for service. Both part numbers include the appropriate injector retainer for the 1985-1986 fuel rail.

1987 Cimarrons: Use only the Rochester-Multec injector, P/N 17111799, for service (includes appropriate injector retainer for 1987 fuel rail). Only the Rochester-Multec injector is compatible with the new GMP4 ECM used in the 1987 Cimarron.

6. If the car still exhibits the hard start and is equipped with . . .

o Bosch injectors, replace the remaining injectors in the set.

o Rochester-Multec injectors, proceed as follows to identify a leaking injector.

a. 1985-1986 Cimarrons ------------------- 1. Remove plenum. 2. Disconnect and remove cold start valve. 3. Remove retaining nut from stud for fuel lines at head. 4. Remove fuel rail retaining bolts (2). 5. Reconnect cold start valve, and disconnect electrical connector.

1987 Cimarrons

1. Remove plenum. 2. Remove fuel line bracket bolt. 3. Remove fuel rail retaining bolts (2).

b. Lift fuel rail out just enough to leave injector nozzles in the ports.

CAUTION:

BE SURE INJECTOR(S) ARE NOT ALLOWED TO SPRAY ON ENGINE AND THAT INJECTOR RETAINING CLIPS ARE INTACT. THIS SHOULD BE CAREFULLY FOLLOWED TO PREVENT FUEL SPRAY ON ENGINE WHICH WOULD CAUSE A FIRE HAZARD.

Pressurize the fuel system and observe injector nozzles. Replace any injector which leaks more than two drops of fuel per minute.

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.