Markfey

iTrader: (7)

My car is a version 4 sti.

The power is coming in and out mainly in 3rd, 4th and 5th.

1 second it's like a rocket, then nothing and then back in.

Extras added to the car is only a straight through exhaust with decat.

If not the injectors, any ideas what it might be?

moro

iTrader: (1)

If it's a fuel system, then it's probably fuel pump, not injectors. Might also be coilpacks, ignition leads and a ton of other things. Could you please give a better description - i.e. the moment it stops accelerating (the moment of "nothing") - is it rough like you've hitted a wall or is it mild, like it just accelerates slower? Any idea of rpm when it happens?

Markfey

iTrader: (7)

Just had new plugs NGK7's, new leads and coil pack fitted.

When the power dissapears it does feel quite violent. So ive been trying my best to drive it off boost.

I thought it might be a boosting problem but i've had that checked out.

moro

iTrader: (1)

Looks very much like ECU is cutting fuel due to overboost. Are you sure it isn't overboosting? And when this started to happen?

Markfey

iTrader: (7)

It all started a while ago. Looked under the bonnet and noticed an arch of electricity coming from the coil pack. Bought a brand new one. After fitting it i could still hear a a cracking sound.

Bought new leads and had a full service. While there i was talked into getting a hayward and scott decat pipe to go with the rest of my 3" system.

Now still have the problem but with no cracking sounds.

Can it over boost without playing with it?

TimH

iTrader: (11)

decat+no remap=overboost+boost spikes

overboost+boost-spikes=good risk of engine damage

imho

moro

iTrader: (1)

Yes it can overboost because of free flowing exhaust. Tim's right. The best option would be to get it mapped. Otherwise you need to lower the boost. One cheap way to do that would be changing the boost pill to a slightly bigger one.

Steve Whitehorn

iTrader: (13)

Snap

Markfey

iTrader: (7)

Cheers guys. Helps a lot.

I was hoping to get the walbro fuel pump, fmic from harvey and a air induction kit before the remap.

Am i right in thinking Mr jollygreenmonster is the man to speak to and it will be roughly £1000 for a simtek ecu and remap?

Any ideas once you've paid for the ecu, licence and remap how much it is for each remap after mods?

TimH

iTrader: (11)

Yep - approx £1000 for simtek, £150+VAT for map tweaks thereafter: plus any RR costs.

Markfey

iTrader: (7)

And the answer was......

Thought it best to update you all. After i informed the mechanic that i had brand new leads and plugs etc he was scratching his head with the problem.

It turned out the leads are total pants and can't handle high boost. He said they are some of the worst he's ever seen and they've even split within about 300 miles.

To name and shame the company Ignition leads - performance ignition leads UK i'm very upset as they stated numerous things such as capable of handling 600bhp etc. Used on rally cars.

Haven't got the car back yet but the mechanic is saying it's running beautifully.

Thanks for all your help guys, again........

moro

iTrader: (1)

Thanks for the update and glad to hear you're back on track!