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Ford cmax 1.6 duratec hesitation accelerating


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Hi guys, my 1.6 duratec 2008 ford cmax has a problem when accelerating it hesitates right through the power almost feels like a misfire. I've change plugs, plug leads and the coilpack and it is still the same does anyone know what this could be? Any advice would be appreciated thanks

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28 minutes ago, kylet19901 said:

Hi guys, my 1.6 duratec 2008 ford cmax has a problem when accelerating it hesitates right through the power almost feels like a misfire. I've change plugs, plug leads and the coilpack and it is still the same does anyone know what this could be? Any advice would be appreciated thanks

have you checked the OBD port for error codes? could it be the fuel side of things? Fuel pump issue, fuel filter clogged, injector issues? The injectors would probably throw a code, or a lean code may be observed if it was the fuel. I have heard of vacuum leak issues also causing a hesitant engine.

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This is what google provided below.

Engine hesitates during acceleration Inspection Estimate for Ford C-Max

Engine hesitates during acceleration Inspection Service

 

It can be frustrating for any driver to expect certain acceleration from their vehicle only to find that the vehicle seems to be hesitant while speeding up. This hesitation could be potentially dangerous in situations like entering and exiting the highway from an off-ramp, where acceleration may be necessary to merge with traffic. A vehicle that struggles or hesitates to accelerate may be unpredictable and moments of hesitation may be coupled with equally dangerous moments of surging or unexpected acceleration. When a vehicle is hesitating during acceleration, it should be inspected by a mechanic.

How this system works:

A vehicle with a combustion (gas or diesel) engine requires an exact mixture of fuel and air to run efficiently. If this mixture is thrown off in any way, it may result in an engine running too lean (not enough air), or too rich (not enough fuel). An engine that is hesitating to accelerate is most likely dealing with a fuel/air mixture that is too lean. Engine’s that are running inefficiently will begin to show signs like hesitation which will only become worse over time. If you notice some symptoms like hesitation, you should have your vehicle inspected immediately.

Common reasons for this to happen:

  • Mass Airflow Sensor: The mass airflow sensor measures how much air is entering the engine and relays this information to the vehicle’s computer so that the right amount of fuel can be delivered from the fuel injectors. When a mass airflow sensor begins to fail, it will typically generate an error code or “Check Engine light.” This warning may be accompanied by hesitation while accelerating, or while driving up a hill. A vehicle with a failing mass airflow sensor may also stall soon after starting.

  • Fuel Pump: The fuel pump in most modern vehicles sits inside the fuel tank and pumps fuel up to the engine. If a fuel pump cannot provide the correct pressure, fuel may have difficulty making it to the engine. A vehicle that hesitates while accelerating or while driving up a hill may have a weak fuel pump.

  • Throttle position sensor: A throttle position sensor tells the vehicle’s computer how far the throttle is open and how hard the accelerator is being pressed. The computer is then able to adjust the fuel/air mixture going to the engine so that is stays at an appropriate level. If the throttle position sensor is not working properly, it may be sending incorrect information to the vehicle’s computer. The computer may then not provide the engine with the correct amount of air while accelerating, causing a hesitation sensation.

  • Dirty/failing fuel injectors: Fuel injectors spray fuel in a fine mist into the cylinder where it is mixed with air and ignited by a spark plug. Fuel injectors may become dirty over time and not be able to provide as much fuel to the cylinder as is needed. Dirty fuel injectors may cause the engine to run lean which will in turn, cause hesitation when accelerating.

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Thanks i have tried the obd reader but no fault codes come up. As for fuel filter from what I've read my model doesn't have a serviceable filter although I might be wrong. Il have a good look at that page though thanks.

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1 minute ago, kylet19901 said:

Thanks i have tried the obd reader but no fault codes come up. As for fuel filter from what I've read my model doesn't have a serviceable filter although I might be wrong. Il have a good look at that page though thanks.

Is your cmax diesel or petrol?

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1 minute ago, kylet19901 said:

Its a 1.6 petrol duratec engine.

Don't quote me but I thought most petrol engines have to have a removable petrol filter to stop the crap getting into the engine or blocking injectors. Maybe someone with better experiences will comment on this post.

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1 hour ago, kylet19901 said:

Thanks i have tried the obd reader but no fault codes come up. As for fuel filter from what I've read my model doesn't have a serviceable filter although I might be wrong. Il have a good look at that page though thanks.

What reader did you use a lot can't read all the codes you need Forscan  free download and a modified ELM connector you need a modified one so you read the hi and lo buses tunnel rat do the best ones.

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On 1/9/2021 at 9:50 PM, pragmatix said:

What reader did you use a lot can't read all the codes you need Forscan  free download and a modified ELM connector you need a modified one so you read the hi and lo buses tunnel rat do the best ones.

Excellent thanks ive just received delivery of this setup and its showing no fault codes. Do you know what I could check on live data etc? Thanks

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