Hard Start or Extended Crank Time After A Hot or Cold Soak
Number 86-6 (Gasoline)-71 Date 3/87TIME AFTER A HOT OR COLD SOAK
Subject: HARD START OR EXTENDED CRANK
1985-86 6000, SUNBIRD, FIREBIRD AND FIERO
VEHICLES EQUIPPED WITH 2.8L PFI ENGINES
Some 1985-86 6000, Sunbird, Firebird and Fiero vehicles with the 2.8L MPFI 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 using procedures defined in the following steps.
NOTICE: THIS HARD START CONDITION SHOULD NOT BE CONFUSED WITH ROUGH IDLE OR POOR ACCELERATION DUE TO RESTRICTED FUEL INJECTORS. VEHICLES WITH ROUGH IDLE OR POOR ACCELERATION SHOULD BE SERVICED USING PROCEDURES FOR ON-VEHICLE CLEANING OF INJECTORS DEFINED IN PREVIOUS SERVICE BULLETINS.
1. Attach a fuel pressure gage to the fuel rail pressure fitting. Turn ignition to "on" and pressurize fuel system.
2. If the fuel pressure leaks down more than 10 PSI in 2 minutes with the fuel feed and fuel return lines restricted, proceed to step
3. If the pressure does not leak down, perform procedures in Chart A-7, Fuel System Diagnosis, in Section 6E3 of the Service Manual.
3. Locate and replace leaking injectors using the following procedure.
- Connect fuel gage, J-34730-1 or equivalent to fuel pressure valve. Wrap a shop towel around fitting while connecting gage to avoid spillage. Route bleed hose into an approved container and open valve to bleed system.
- Remove plenum, cold start valve and remove fuel rail bolts. Leave fuel lines connected.
- Reconnect cold start valve. Connect one end of a hose to the nozzle of cold start valve and route the other end into a gasoline container.
- Lift fuel rails out just enough to leave injector nozzle in the ports.
CAUTION: BE SURE INJECTOR(S) ARE NOT ALLOWED TO SPRAY ON ENGINE AND AND THAT INJECTOR RETAINING CLIPS ARE INTACT. THIS SHOULD BE CAREFULLY FOLLOWED TO PREVENT SPRAY ON ENGINE WHICH COULD CAUSE A FIRE HAZARD.
- Pressurize the fuel system.
- Lift each side of fuel rail up and observe for leaking injectors or cold start valve. Replace any parts that leak in excess of the following rates:
Component Part Maximum Leak Rate *
Injector 1 drop / min.
Cold Start Valve 1 drop / min.
* Injectors and cold start valve should be wiped dry with a clean shop towel prior to timing the injector leak rate.
Use applicable labor times and operation numbers.