Skylark L4-138 2.3L DOHC VIN D MFI (1988)
Manifold Pressure/Vacuum Sensor: Customer Interest
Engine - Miss and/or Code 33
Bulletin 88-6E-5
Date Dec. '87
Ref. No. 88-059-68
Corp. Ref. No. 876504
SUBJECT:
ENGINE MISS AND/OR CODE 33
MODELS AFFECTED: 1988 SKYLARKS WITH THE LD2 2.3L QUAD 4 ENGINE (VIN CODE D)
A condition of an engine miss and/or a "Service Engine Soon" light with Code 33 stored in ECM memory may be caused by a kinked vacuum hose to the
MAP sensor on a 1988 Skylark equipped with the Quad 4 (LD2) engine. When this condition is present, the engine ignition timing is affected.
This condition can be corrected by inspecting and removing any kinks in the MAP sensor vacuum line prior to performing any additional diagnostics.
