Fuel Metering Body - Attaching Screw Torque

87chevy19
GMC NUMBER: 87-T-85

GROUP: 6C-Engine Fuel

DATE: September, 1987

CORPORATE
NUMBER: 736522
SUBJECT: RETIGHTENING FUEL METERING BODY ATTACHING SCREWS ON TBI MODEL 700

MODELS: ALL 1987 S/T TRUCKS AND M VANS EQUIPPED WITH 2.5L (VIN CODE E) ENGINES

FIGURE NO. 1:

On 1987 S/T trucks and M vans using the model 700 TBI unit (2.5L engines only), any time the TBI attaching bolts/studs to the intake manifold are installed or retightened, the fuel metering body attaching screws should also be retightened (See Figure No. 1). Tightening the TBI attaching bolts may cause the fuel metering body gasket to compress and allow the fuel metering body attaching screws to loosen. When servicing the model 700 TBI on 2.5L (VIN Code E) engines, tighten TBI attaching bolts/studs to 17 N-m (13 lb. ft.). (Refer to Section 6E (TBI) in the fuel and driveability manual for additional information.) Tighten the fuel metering body attaching screws to 6 N-m (53 lb. in.).
If the fuel metering body is removed from the TBI unit, be sure to apply threadlocking compound to the fuel metering body attaching screws. Most GM TBI repair kits include a small vial of threadlocking compound. If this is not available, use P/N 12345382 (Loctite 242) or equivalent. It is not necessary to apply threadlocking compound to the fuel metering body attaching screws if they are being retightened only AND the TBI attaching bolts/studs have ALREADY BEEN tightened to the proper torque. Proper TBI bolt torque sequence is important:
TBI attachment bolts/studs first, then fuel metering body screws.