Need your help guys

[REX-ETR]

Hey guys hows it going? Just need some help with a weird problem i am having at the moment.

My car was running like a dog, put anymore than a quater throttle and it starts back firing, jerking back and forwards like crazy and blows black smoke (rich). I noticed that there wasnt a line off the wastegate actuator, so i rigged up a boost controller. Took her for a run and it was running like a dream and pulling hard. However the car ran out of fuel whilst idleing the other day. So i got the old jerry can out and put it to good use. Anyway took it for a drive and it was acting up doing the same thing. Back firing, cant put your foot down much without it jerking back and forwards, however if you just ease the throttle it will go to 10psi no problems, just when you try to give it a bit of stick. I am not quite sure if i can hear a vacum leak behind the intake manifold. It idles all over the show and was going up and down 5hg on the boost gauge yesterday. It revs fine on the spot with no hesitations. Just got me stumped as to why it worked fine after i put the boost controller on.

What do you guys think?

Its a vr4 motor in my cordia by the way running a wolf comp

Regards
Nathan

 

[JSTYLE]

fouled plugs.. or possibly wrong gaps.

Jon

 

[REX-ETR]

Shit forgot about that! had a look at them the other day and they were BLACK and signs of running veryyyy rich, looked pretty bad. Will change them tomorrow, running BP6ES

Regards
Nathan

 

[SIVART]

it must be tunning

my car is the same, I have gone through 3x sets of plugs

now trying BP7ES

even same boost wont go over 10psi

 

[Entaran]

What brand/size injectors are you using?

Any other fuel mods (pump, piping size?)

Goes for you too sivart.

 

[REX-ETR]

I am running VR4 blue top injectors, and a VL turbo fuel pump. Sivart my tune is tuned to run a bit rich, but the only thing i didnt get is it running fine one day and not the next. I found one vac leak and fixed it and can hear another so will also have to fix that tomorrow.

I am chewing thru petrol like anything at the moment though. 15ltrs lasted me two 10 min drives and the rest was idling.

Regards
Nathan

 

[Entaran]

Try getting an Adjustabel FPR to bring your fuel pressure back down.

The VLT pump will be pushing fuel through those lines like crazy, they're significantly more powerful than the vr4 pump from memory.

 

[REX-ETR]

Hey guys.

Yeah i have got a FPR here to go on along with a few other things when i get the time mate.

I replaced all the vac hosing with silicon hose today and replaced the plugs and she is back to normal and running like a dream.

However my car is tuned to run a bit rich, would BP6ES be too cold for it you think?

Regards
Nathan

 

[JSTYLE]

Hey guys.

Yeah i have got a FPR here to go on along with a few other things when i get the time mate.

I replaced all the vac hosing with silicon hose today and replaced the plugs and she is back to normal and running like a dream.

However my car is tuned to run a bit rich, would BP6ES be too cold for it you think?

Regards
Nathan

BP6ES are too hot.. run a set of BP7ES Minium.. if you want some decent power.. go to the set of BP8ES.. but id stay clear of the BP6ES as ive fried one before.

Jon

 

[REX-ETR]

Hey jon thanks for that mate. Shes back to the way it was. This is one of the new spark plugs after 10 mins of driving it. They all got near 1mm of black carbon on them, so it doesnt idle and bacl fires now. Once it gets to 8psi it backfires as if it dumps heaps of fuel. So i should try 7es before i take it in for a dyno tune?.