Engine runs strong when cold, once it warms up from low rpm the engine feels like its choking & it shakes , it goes away after around 4k rpm.
My car has a manual transmission.
This may be caused by a number of things such as a bad fuel pump relay or potentially a faulty ignition coil. Ignition coils are coated with a varnish-like insulation that becomes brittle over time after being stretched then contracted repeatedly. The insulation develops small fractures that open when heated and close when cooled. When open, they allow shorting of coil windings and decrease or eliminate the coil’s ability to function. This type of temperature cycling happens because every time you shut the engine off, the fan stops running, the coolant stops flowing and the temperature under the hood rises. Every time you start the engine again the coolant flows, the fans turn on, and the temperature drops. When this heat dissipates and is absorbed under the hood, it is trapped causing this cycling effect. Other components that contain heat sensitive materials include parts like fuel injectors, igniters, and some sensors. Any of these may be potentially subject to this same kind of heat cycling problem which can be very difficult to trace. I would recommend having an expert from YourMechanic come to your location to take a look at your vehicle.
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