Hi ,

Ive got a 04 Evo VIII UK spec FQ300 , after reading various posts i could resist putting a cat by pass pipe on and a blitz air filter , i didnt want to go crazy on the mods due to the obvious worry of voiding any warranty's.

The other day i was gently breaching the 140mph mark when the engine stopped sharply and then started almost instantly. Now it didn't actually stop but it was like when you lift of the pedal while on full boost . It has done it only once previous and afterwards it drives like nothings happened. And on both occasions i was in some kind of hurry with the pedal flat to the floor.

Someone has mentioned it might be a fuel cut off sensor or something im sure this is common knowledge amongst you regular turbo guys, what is it ?

 

Maybe your intake is causing you to run lean? Has this ever happened before?

 

Sounds like Fuel Cut.....

 

Fuel cut is what you experianced.

When the Mass Airflow Sensor shows you have more airflow than normal (way more than a stock car would run) it will completely cut fuel delivery.

Keith

 

the blitz air filter made it run much leaner and you hit fuel cut.

 

Running leaner would put him further away from fuel cut, not make him hit fuel cut.

Keith

 

what is your boost set at?...if ur foot was to the floor , the evo tends to over boost in fourth and fifth gear...so you could be running close to boost cut....and thats what happened..

 

Fuel cut is controlled by airflow and IDC, it is not controlled by air fuel ratio. If the ECu sees too much airflow it will shut down.

 

What wereyour RPMs at?

 

Like i said it has only happened once before and only when im flooring it 1st time i was in third i think and last i was in 5th and on both times the revs must have been about 6000 rpm.

My car is standard other than the cat bypass and air filter so i dont a boost gauge.

Is it doing any damage and what can be done to help it ?

 

your air filter might be throwing off the MAF sensor readings.

 

Are you positive your were at 6000 RPMS? It is very easy to hit fuel cut if your riding out a gear. Im not saying I don't belive you Lol I just want to make sure your positive!

 

I think it 6000rpm i definately wasnt lifting off the pedal and was goind for a top speed run lol.

 

And if the car is running lean, that means the ECU is seeing less air flow than the motor is actually getting.... putting you farther away from fuel cut.

Keith

 

Sounds just like fuel cut...when you hit the rev limiter, the engine just pulses, but fuel cut feels like you hit a wall, exactly what you described. It's your air filter...you need to get a tune.