violent jump

[evokev]

hey guys was wondering if anybody could help me....i have an evo 5 and lately when i drop a gear and accelerate hard the car makes a violent jump as it accelerates and then is fine again...mechanic reckons it could be fuel starvation...

any ideas????
all help appreciated

 

[stroker kid]

hey guys was wondering if anybody could help me....i have an evo 5 and lately when i drop a gear and accelerate hard the car makes a violent jump as it accelerates and then is fine again...mechanic reckons it could be fuel starvation...

any ideas????
all help appreciated

id say its fuel cuttin, wat boost is it at? a fuel cut defender is 1 way ta solve it

 

[evokev]

im not sure the car is pretty standard will try that....cheers for your help

 

[sponners]

probably fuel/boost cut.

search on mlr for more info.

(do NOT fit a FCD to rectify the problem)

 

[hairybeanbag27]

yeah my 8 dose it make sure your running v power and also when was it last serviced ?
dose sound like fuel problem though im going to upgrade the fuel pump and injectors soon

 

[evokev]

yea am going to change fuel filter to see does it make any difference if not going to upgrade the fuel pump

 

[sponners]

does it feel like hitting a brick wall then the powers returns again (quiter violent)?

what boost pressure are you running?


its actually caused by airflow.

induction kit? bigger exhaust? raised boost? these can all cause the fuel cut.

 

[evokev]

thats exactly what it feels like...car has standard exchaust and has ralliart air filter not sure of the boost cause the boost gauge not workin...can you adjust the boost?

any idea how to solve it

thanks for your help

 

[sponners]

where are you?

if the car has a aftermarket boost controller (electrtonic or manual) turn the boost down.

it is probably caused by either a air leak in the boost system or more likely the actuator is sticking (common fault)

if you search the mlr for actuator test you will find all the info you need.

 

[evokev]

i am in ireland...the car doesn`t have a boost controller
i will pass your info on to my mechanic see if he can sort it out
cheers for your help much apprieciated

 

[Steveatron]

Im having the same problem with my 5, its completely standard.

 

[crosser]

does it feel like hitting a brick wall then the powers returns again (quiter violent)?

what boost pressure are you running?


its actually caused by airflow.

induction kit? bigger exhaust? raised boost? these can all cause the fuel cut.

finally! i have only had my evo about two weeks and dont know alot about them. i am having that problem that you mentioned above with my evo 6. when pushing hard it makes a vilolent jolt (feels like hitting a brick wall) and cuts power then returns. it usually happens in higher gears when foot is flat to the floor.
the car has only got an induction kit, exhaust and dump valve.

any ideas what i could try? thanks ant

 

[Steveatron]

please help

There are so many idea to why its happening does anyone actually know why?
Beucase ive been told could be fuel, air flow the turbo its self and im just stuck cos i havent got enough money to be buying new bits

Plus mine usuallyt starts doing it when i go over 0.5 on the boost gauge like i can floor til it goes over that then when it does just jumps and shit

 

[sponners]

the boost/fuel cut is caused by too much airflow.

breathing mods such as exhausts/decats, induction kits all increase the airflow which can cause a fuel cut if the airflow is increased enough.

Fuel cut on the evo 6 is approxmately 1.2-1.3bar of boost. (will happen more in higher gears as there is more load on the engine (more load = more airflow)

a boost leak in the system will also cause this.

Try to avoid hitting the boost cut as it puts a lot of strain/shock on the whole engine/drivetrain.

another common cause on older evos is the actuator diaphragm leaks, and also the actuator rod itself can seize causing higher boost.

So if your over boosting then you want to check the actuator is operating properly, and also check for boost leaks.

If the above is ok then you need to fit a boost controller to turn the boost down or get the car remapped.

......DO NOT fit a fuel cut defender (these are bad news)


hope that clears a few things up for you guys

 

[Steveatron]

I had a post on here about My evo 5 which did the violent cut and I had my spark plugs upgraded and it sorted it! So try that

 

[MR.LANCER]

if its standard then your problem lies on the spark plugs or most likely the actuator it self

 

[beags]

Cant believe it read this yesterday evening and this morning my 4 started doing the same thing.

I have an intake system but no boost control, A Decat and downpipes.
Looks like a garage job then.

 

[ElDopesta]

Is this contagious????

El

 

[EVO_RON]

looks like it hope i dont catch it only just got mine running the way i want it lol my prob was a fuel pressure regulator

 

[rich_f]

when i had a problem the same as this (feels like hitting a brick wall) turned out to be boost selonid but seems strange if 3 + people have had the same problem in a short space of time but might be worth checking the pipes havent come off.