1987 Jeep Cherokee Chief 4x4. Manual Trans. Swapped the 87 cherokee 4.0 L6 engine with a 93 cherokee 4.0 straight 6. Everything swaps over and bolts up the same. Once it turns over it jumps instantly to 3500 rmp... it doesn't die down but will only continue to climb. Any ideas? Thought vacuum but can't be sure... vacuum lines match diagram under hood.
distributor is from the 87.
distributor is from the 87.