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Eric, Automotive Repair Shop Manager
Category: Mazda
Satisfied Customers: 31334
Experience:  20+ yrs. experience as repair shop manager and technician.
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Jerks and lurches at low speeds

Customer Question

jerks and lurches at low speeds
Submitted: 1 year ago.
Category: Mazda
Expert:  Eric replied 1 year ago.
I am sorry that you have not been helped yet. I just came online and saw your question
Automatic or manual transmission
Does it feel like this is in the engine or transmission?
What have you done so far to try to correct it?
If check engine light is on, we need to retrieve the fault codes first and let me know what they are.
Customer: replied 1 year ago.
Manual. Engine. No check engine light. Changed fuel filter.
Expert:  Eric replied 1 year ago.
Does it seem jerky at all lower speeds, or just after changing gears?
Customer: replied 1 year ago.
At all lower speers.
Expert:  Eric replied 1 year ago.
Ok, it does sound like engine and not transmission. And sounds more of a fuel delivery issue
We need to check the fuel pressure while on a test drive. Two ways to do this. One is with a scan tool with live data to monitor the fuel pressure. The second is to hook up a fuel pressure gage with long hose so that you can tape the gage to the windshield to monitor it the pressure.
Pressure should be 38 - 46 psi. If it is dropping below that on test drive when it starts jerking, then the pump is faulty. If it goes above that, then it is the fuel pressure regulator.
If within specs, then the fuel injectors will need to checked.
Expert:  Eric replied 1 year ago.
I noticed we have not yet resolved your concern you asked about. I would sure appreciate it if you would reply so I can offer my skills and knowledge and repair guide access to help as best I can.
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