ENGINE STALLS WITH STEERING LOAD -- CORRECT PART NUMBER
VEHICLES AFFECTED: 1985 CADILLAC DEVILLE AND FLEETWOOD
Some 1985 FWD Deville and Fleetwood vehicles may exhibit an engine stall followed by an immediate restart during parking maneuvers with an engine at normal operating temperature and with power steering load applied (steering at full lock). A new PROM has been released to eliminate the "engine stalls" symptoms during the above operating conditions.
The new PROM (P/N 1228112 FED and 1228113 CAL) has revised idle speed during warm engine operation. Warm engine idle speed has been increased to 650 RPM and the PROM has revised idle speed control during gear changes from drive to reverse.
Before replacing the PROM, perform the following checks:
1. If the vehicle loses engine power or stalls under any other condition than described above, see the diagnosis section in the Service Information Manual, Section 6E, subsection B, page 6E-45, "Intermittent Engine Stalls, No Codes."
2. With the engine running, perform ECM switch tests (E 7.1 - E.7.8). Repair any switch test that does not pass using the appropriate trouble tree in Section 8Dl of the 1985 Deville/Fleetwood Service Information Manual.
Check PROM I.D. (parameter P.1.6). If PROM I.D. is not 216 for Federal Emission System or 227 for California Emission System and, if all of these system performance checks indicate normal vehicle operation, replace the PROM with P/N 1228112 for Federal Emission or 1228113 for California Emission System.
If the PROM does not fix the stall condition, refer to the 1986 Deville/Fleetwood Service Information Manual Section 6E, subsection B "Symptoms". Pay particular attention to the following checks:
1. Connect a 0-15 PSI fuel gauge to the fuel pressure test point.
CAUTION:
When taking the following fuel pressure readings, be sure the fuel pressure gauge is securely attached to the pressure test point. Be careful to route the pressure gauge hose away from the exhaust manifold, any other hot surfaces, and any sharp edges that could cut or damage the hose. Failure to do so may result in a fuel leak while diagnosing the car.
Duplicate the complaint while observing fuel pressure. If fuel pressure fluctuates during the maneuver, repair cause of fuel pressure fluctuation.
2. Block the drive wheels and scope ignition system with the engine under idle load condition in drive or reverse. Look for spark plugs, ignition wires or coil, cap and/or rotor breaking down under load. A problem such as a cracked plug may cause abnormal engine operation, yet be difficult to detect on a scope. Replace any suspect spark plugs or ignition wires and inspect the cap for arcing before proceeding with diagnosis.
CAUTION:
Brakes must be applied at all times.
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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.
