Mrnoonfruit

hi guys, im a newbie and have recently bought an impreza 2000 uk car with a few mods, the bloke i bought it from told me about a problem in 4th and 5th gears that was on the car.When you floor it in these gears it accelerates then all of a sudden its as if ive tapped the brake with my left foot, then she carrys on as normal. this has happened quite a few times now.I was told that it could be the coil pack,but i changed it and its still happening.I was then told that it could be my magnecor leads causing it and i should go bk to standard leads.
please help!!!
thanks guys

c_maguire

You need to tell everybody what model year the car is and what the mods are...
Kevin

dan83590

Prob fuel cut.

Do you have a boost gauge? What is the max boost?

Mrnoonfruit

Engine wise:Forged Pistons, Forged Conrods,Walbro Fuel Pump, Prodrive downpipe,decat and full system,bailys dump valve,piper X induction kit,Prodrive reampped ECU,Samco hoses,
Shes running about 0.8 bar boost

c_maguire

What year car is it? The Prodrive ECU on a 99/00 car is mapped for 1.1bar/16psi boost and wants super unleaded to run right
Kevin

Mrnoonfruit

she is a 1998 car. i run it on super unleaded

The rookie

iTrader: (1)

It sounds just like the overboost fuel cut I was getting, dropped the boost by 0.05bar - sorted....

Simon

Mrnoonfruit

Like i said, im a newbie, what does that mean exactly, what do i need doing?

Mrnoonfruit

ive been told today is hould by braided leads as they wont take in so much heat from the engine, anyone know anything bout these?

Mrnoonfruit

anyone???

scooby abuser

in theory thats right, but the casing of these leads are silicon based so heat shouldn't affect them, unless on has a broken or damaged core. Try metering all leads out and check they are all the same impedance.
I would get the boost checked incase it is overboosting, could cause long term damage, won't gat it in the low gears as the boost from the turbo is higher in high gears

klunker

iTrader: (4)

The first Subaru I test drove had this issue, he replaced the coilpack and it went a lot smoother the next test run............................................... .................................................. ...The HPI report on the other hand, stayed as bad as it was the first time.

Mrnoonfruit

thanks guys, the coil pack has been changed and its still doing it, im having new leads put on so hopefully that will sort it

Claaarkio

iTrader: (1)

Sounds more like Fuel cut to me, not electical shorting due to leads breaking down.

Watch the boost when you floor it in 4th / 5th see if it climbs up to over 1bar?

Dave

Mrnoonfruit

Ive had the coil pack changed, plugs, Leads and its still doing it, anymore help gratefully appreciated guys.

exvaux

iTrader: (1)

Ive got the same problem if i hold revs at 3k then floor it car hesitates and judders for a second then pulls away again no cel light

davesti330

I reckon it sounds like fuel cut. My mate had it in his 200sx and it felt like you were going to go through the windscreen on full boost. Am i right in thinking a fuel cut defender would solve it??

Mrnoonfruit

CEL is check engine light on dash?
no nothing comes on

Mrnoonfruit

Hi, what is a fuel cut defender?

exvaux

iTrader: (1)

dunno about the 98 but the 99 model the fuel cut is over 1.7 bar so i doubt id be hitting it

Mrnoonfruit

Dont know if this helps guys, but when i boot it, she boosts to 18Psi, then drops to 14Psi

Mrnoonfruit

guys im so pissed off, my local garage has tried everything thats been suggested, changed coil pack, plugs, leads, checked oil to make sure not too full, diagnostic computer says nothing wrong, but she still does it, im seriously think bout just getting rid. Please help guys

Claaarkio

iTrader: (1)

So thats 1.24bar on over boost, thats high. you will be hitting fuel cut i am sure!

on a version 2 the fuel cut is set at 1.1 bar, not sure on your later car but i bet 1.24 is higher or just about there!

you need to look at why you are getting such a peak when flooring the car.

Dave

classicscoob

iTrader: (1)

Dont get rid mate, there are enough enthusiasts on this forum with the knowledge to help and solve this problem

Mrnoonfruit

just spoke to someone and they suggested that the car is over boosting, how can i find out if this is the case?

Mrnoonfruit

Anyone know where i can get a HKS FCD from, also is it something i can fit myself, or do i need a garge to do it for me??

rossd001

I got the same problem on my 95 import wagon, but my car only seems to do it every now and then! Exactly the same symtoms as you are reporting but I only get it once or twice a week if that.

My guess is that if it is the fuel cut becasue of over boosting then yours must be well off the scale to do it all the time and my one is just peaking at the cut off point thus only doing it sometimes...???

Plus my one never does it at night?? Random comment, but all info helps??

Ayde

iTrader: (6)

Have you tried cleaning your boost solenoid out 10 minute job, a fouled up one gives the symptoms you are experiencing. Do this before you spend anymore money. Its common and im suprised no one has told you to do it yet?

Ayde

iTrader: (6)

Just to add my MY99 has done similar running std boost will hit normal pressure in 4/5th then pull back about 5 psi then back up to normal. I imagine as you are running higher boost this would exagerate the effect. Do a search for "Boost Solenoid" - its common and you will find a guide on how to clean it out. You basically unbolt the solenoid and disconnect the pipes and then get under the dash and connect a pair of the connectors (cant remember if its the black or green) turn on the ignition and the solenoid will start clicking rad fan goes on and off etc... Blow some WD-40 through it and catch with a rag. Turn of ignition and disconnect the plug under the dash. Disconnect associated pipes and give them a blow through too. Let it all dry out and then put it all back together. Do an ECU reset if you like. Think the solenoid gets fouled up if you rev excessivelly in neutral or 1st from memory.

rossd001

I wouldnt even know where to start!!!