Some 1986-1988 Broughams may experience a condition of an engine miss at the #6 cylinder. This condtion may be caused by a vacuum leak in the vacuum circuit between the vacuum fitting in the #6 intake manifold runner and the hoses and tees connected to that fitting (see Figure 1).
To repair this condition, the following items should be examined:
- Check for split vacuum hose between the vacuum fitting and HVAC vacuum tank (refer to Figure 1). - Check HVAC vacuum tank for cracks or open seams. - Check for loose/disconnected vacuum hoses/fittings. - Check remainder of hoses for splits.
If the above repair does not correct the misfire condition, refer to the appropriate model year Cadillac Service Information Manual, Section 6El "Symptoms".
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.