DIESEL INOP METERING VALVE SENSOR INFORMATION
MODELS AFFECTED: 1985 DEVILLES AND FLEETWOODS EQUIPPED WITH A 4.3L DIESEL ENGINE
The 1985 front wheel drive Devilles and Fleetwoods equipped with a 4.3L diesel engine contain a Metering Valve Sensor (MVS) in the diesel injection pump.
Currently, when these injection pumps are removed from vehicles and sent to Roosa Master dealers for repair, a rust preventative in the test fluid used in calibration stands at the Roosa Master dealers will coat the MVS and render it inoperative. A new test fluid, which has no affect on the MVS, is in the process of being introduced.
Until such time as the new test fluid is in the calibration stands, it will be necessary for dealers to flush all injection pumps with diesel fuel and, when noted, adjust the MVS after they have been installed on the car.
The Roosa Master dealer will identify those pumps requiring flushing and/or adjusting by attaching a tag to those pumps. The tag will include the listed information: Required Stanadyne No. Color Operation(s) ------------- ------ ------------ 99195 Yellow Flush Only 99196 Red Flush and Adjust
Flush all pumps using the service procedure listed in this bulletin. Those pumps requiring MVS adjustment should be serviced using the procedure contained on page 16 in Section 6C of the 1985 FWD Service Information Manual after the flushing procedure has been completed.
Flushing the Metering Valve Sensor (MVS) - With the Air Crossover Removed
1. Place a shop towel under the injection pump.
2. Disconnect the HPCA/Fast Idle switch lead at the cylinder head bolt temperature switch.
3. Hold the MVS and remove the MVS adjusting hole plug.
4. Assemble onto a J-28526 adapter (1978-1979 Housing Pressure), a 561888 seal and washer or equivalent (Item 2) and flat washer. Use enough flat washers (Item 3) so that the distance from the seal to the end of the adapter is 3mm (3/32"). See Item 1 in Figure 1.
5.Install a hose fitting into the J-28526 adapter shown as Item 5 in Figure 1.
6. Install the J-28526 adapter with washers and fitting into the MVS adjusting hole. Hold the MVS assembly and tighten the J-28526 tool to 3.5 N.m (30 lbs. in.).
7. Place a four liter (one gallon) diesel fuel resistant container close to the car.
8. Install a length of diesel fuel resistant hose on the fitting and place the open end of the hose into the fuel resistant container.
9. Start the engine and correct any fuel leaks. Run the engine four (4) minutes.
10. Shut off the engine. Disconnect the hose from the fitting, and drain and remove the hose from the container.
11. Dispose of the fuel in a suitable manner. It can be reused in the fuel tank if it is clean.
12. Remove the J-28526 adapter. While holding the MVS assembly, install the MVS adjusting hole plug, (using a new "O" ring if required), and tighten it to 3.5 N.m (30 lbs. in.).
13. Remove the shop towel and clean any spilled diesel fuel.
14. Start the engine and check for leaks.
15. Reconnect the HPCA connector.
For warranty purposes, when removing and replacing the Fuel Injection Pump, use labor Operation No. J5950 at 2.0 hours. Add .3 hour to flush MVS only (yellow tag), or .5 hour for flush and adjustment of MVS (red tag). Staple the tag to the scrapping copy of the repair order as your authorization to perform the operation.
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.
