| Subject: | No Start or Rough Running After Engine Replacement |
| Models: | 1996-1997 Chevrolet C/K Truck |
| 1996-2000 Chevrolet Express, Silverado, Suburban |
| 1996-2000 GMC Savana, Sierra, Suburban |
| Equipped with a 7.4L engine |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Crank no start, or rough running after a 7.4L engine is replaced.
Recommendation/Instructions:
If a 7.4L engine was just replaced, the engine is a crank no start, or it starts and runs rough, inspect for the incorrect crank sensor reluctor. Some replacement 7.4L engines may be built with the incorrect crankshaft sensor reluctor. Compare the crankshaft
sensor reluctor to the old engine reluctor. Most 7.4L engines use a four blade crank sensor reluctor. If the reluctor is not the same, replace the crank sensor reluctor with the proper reluctor, or install the reluctor from the old engine.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
