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Chris, Shop Foreman
Category: Jeep
Satisfied Customers: 3379
Experience:  Jeep Certified Master Tech
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Second opinion] I have a '98 cherokee. The engine started to

Customer Question

Second opinion] I have a '98 cherokee. The engine started to race when I started it.JA: Will the headlights turn on? Is the battery fully charged?Customer: I never thought to check the headlights, battery seems OK. Could it be a vacuum tube?JA: Are you fixing your Cherokee yourself? What have you tried so far?Customer: Yeah, if I can. Just checked the throttle cable to see if it was stuck, seems OKJA: Anything else you want the mechanic to know before I connect you?Customer: Don't think so
Submitted: 4 months ago.
Category: Jeep
Expert:  Richard replied 4 months ago.

Hello, welcome to Justanswer, my name is*****'m a 26 year Chrysler, Dodge, Ram, Jeep technician.

If you checked the throttle valve and cable to see if it was stuck and everything looked good, the only other things that can cause this is a large vacuum leak or a faulty throttle position sensor.

The most common cause of a large vacuum leak would be the brake booster vacuum line came off either at the booster or intake manifold. Visually inspect the large rubber vacuum hose going from the brake booster to the intake to see if it came off or has a split in it. An intake manifold gasket leak can also cause a large vacuum leak and it requires more than a visual inspection find.

The only way to tell if the throttle position sensor is causing this is either to check the voltage with a scan tool/digital multimeter or replace it and see if that solves the problem

I hope this helps you, please let me know!