Fuel - Updated Throttle Body Torque Specs/Precaution
89chevy04GMC NUMBER: 89-T-14
GROUP: 6C - Engine Fuel
DATE: March, 1989
CORPORATE
NUMBER: 736522R
SUBJECT: TORQUE SPECS - TBI 700
MODELS: 1987-1989 M, S, T TRUCKS WITH 2.5L (VIN E) ENGINES
THIS BULLETIN CANCELS AND REPLACES GMC TRUCK SERVICE BULLETIN 89-T-14 DATED FEBRUARY, 1989 TO CORRECT MISPRINT OF MODELS. ALL COPIES OF 89-T-14 DATED FEBRUARY, 1989 SHOULD BE DESTROYED.
On vehicles using Model 700 TBI, when reinstalling the TBI unit, tighten the attaching bolts/studs to:
2.5L L4 Lt. Duty Truck Engine (VIN Code E) - 17.0 N-m (13.0 ft.lbs.). 2.0L L 4 Pass Car Eng (VIN Code 1) - 25.0 N-m (18.0 ft.lbs.). 2.0 L L4 Pass Car Eng (VIN Code K) - 22.0 N-m (16.0 ft.lbs.). 2.5L L4 Pass Car Eng (VIN Code R and U) - 25.0 N-m (18.0 ft.lbs.)
FIGURE 1:
1987 and 1988 Vehicles:
Any time the TBI attaching bolts/studs to the intake manifold are installed or retightened, the fuel meter body attaching screws should also be retightened. Tightening the TBI attaching bolts may cause the fuel meter body gasket to compress and allow the fuel meter body attaching screws to loosen, see Figure No. 1. Tighten fuel meter body attaching screws to:
- 6.0 N-m (53 in.lbs.) If the fuel meter body is removed from the TBI unit, be sure to apply threadlocking compound to the fuel meter body attaching screws. Most GM TBI repair kits include a small vial of threadlocking compound. If this is not available, use Loctite 262 or
equivalent. It is not necessary to apply threadlocking compound to the fuel meter body attaching screws if they are being retightened only, and the TBI attaching bolts/studs have already been tightened to the proper torque.
1989 Vehicles:
For the 1989 model year, model 700 TBI units will not use lockwashers on the fuel meter body attaching screws. Instead, the screws will be installed with a pre-applied thread locking compound. On these units, it is not necessary to retighten the fuel meter body screws after installing or retightening the TBI attaching bolts/studs.
^ If the fuel meter body is removed from the TBI unit, be sure to reapply threadlocking compound to the fuel meter body attaching screws. Use threadlocking compound noted above.
^ Tighten fuel meter body attaching screws to:
3.5 N-m (31 in.lbs.)
^ For vehicles repaired under warranty use the following labor Operation and Time:
Replace TBI Base Gasket
J5485 M Van .5 Hr.
S/T .4 Hr.
J5495 S/T/M .9 Hr.