Q: Bad instant acceleration on high speeds. Works just fine on low end speeds 0-60.

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On the highway when I'm going about 70 I give it gas but the Jeep doesn't react quickly. It will accelerate if you hold it down for a couple seconds but not as quick as it should. I noticed it sometimes doesn't even accelerate. I have to give it even more gas to see if something will happen. It jumps to about 3000-4000 RPM from 2000 and starts to accelerate faster as if it shifted to a lower gear. A couple months ago after a 3 hour long highway drive I got into the city roads with lights. After stopping on a light I remember the Jeep would not want to accelerate lightly. I'd have to give it more gas and it would jump in RPM as if it wasn't receiving enough fuel. My guess is the fuel pump or fuel filter but I wanted to ask a professional before acting. Thank You.

My car has 85000 miles.
My car has an automatic transmission.

Hi there. It is possible, the fuel pump and/or fuel filter is responsible for the lack of power at freeway speeds. It could also be, the exhaust system is restricted ie; restricted/plugged catalytic converter. The lack of acceleration at low speed and high speed may be a faulty MAP (manifold absolute pressure) sensor incorrectly calculating engine vacuum. There are more possibilities and proper diagnoses should be performed. Replacing components without diagnoses, can be expensive and time consuming without resolution. I recommend having your vehicle’s slow to accelerate at 70mph be diagnosed and repaired by a certified technician, such as one from YourMechanic.

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