Hi All!

I am looking for some guidance with an issue with my 2008 Evo X. UK Model, FQ300.

If I am giving it the beans and get into boost and keep pushing through gears, I have an issue with the engine, after shifting only, the engine misfires a couple of times. It *feels* like a fuel issue, though I am not sure, hence my question. Only when in boost, only after changing gears, happens when shifting into 3rd and 4th under those conditions.

Bit more about the car; 60k miles, full service history, well looked after, previous owner stopped using it in ~2019 but kept it serviced and did ~500 miles per year until I bought it last year. It's had a new clutch which it needed.

I do not know for sure, but it may have been mapped in the past, it has an aftermarket cat back (records show the stock was corroded on a service inspection, previous owner decided to put a better sounding exhaust on, glad he did). I see no evidence of the boost solenoid being swapped. The engine hits redline at about 7600 RPM, which to my understanding isn't stock (correct me if im wrong), having driven similar cars in the past, 300hp feels about right, could it of had a map badly put back to stock causing these issues?

I have a bluetooth OBDII reader hooked up to torque pro, though the sensor readings I can get seem limited, the most useful ones that work to my knowledge are AFR and boost pressure, there is a knock sensor readout, it does not increment when I have this issue (though I am not saying this is reliable). No codes come up when scanned.

I have been slowly getting this car back to a fully loved state, I do want to get it to 350-380 hp, as I think all I'm missing is a boost solenoid and map, but I don't want to take it to a tuner with engine issues, obviously. As well as concern something is wrong.

Cheers!

 

Buy the open port 2.0, download Ecuflash and Evoscan. Log your car to see what the AFR and timing is under those conditions. If you cant do that then take it to a reputable tuner and have them log it. It may just need a tune
If you are mechanically inclined then get a boost leak tester and check for boost leaks too. Pay attention to the throttle body seals when performing the boost leak test as they tend to leak esp. on such an old car.
Then report back and see if one of the gurus can help you out

 

That's great, thanks for the reply. I will get a proper tool and get some decent logs. Anyone you'd recommend to take a look at them?

I was considering looking at the air path anyway and cleaning it, so I can check the seals and seating at the same time. I don't have a boost leak kit, but I do have a compressor so it's an option.

Thank you again.