Triple filtered

iTrader: (26)

Ok,

Its an MY00 uk turbo, maffless ecu so no probs there.

The car is absolutely murder to start from cold. Can take easily 10 times turning it over for 5 seconds at a time before it starts then runs like sh"t until its warm.

After that it starts and runs fine except for the poor fuel comsumption. I've had 5 Imprezas and this is by far the worst MPG. Even tickling it I struggle to see 30 miles from a tenner.

I'm changing the coolant temp sensor, lambda and knock sensor this week.

Anyone else got any ideas of other things it could be?

joz8968

iTrader: (13)

If those sensors don't get it sorted, then could it be the throttle position sensor (TPS) or neutral position sensor (NPS)? What about the idle speed control valve (ISCV) - may need a clean or new one?

Just guesses really...

joz8968

iTrader: (13)

Have you not yet done a fault code check?

EDIT: Scrap that (MAFless ECU)

markjmd

iTrader: (11)

Over-fuelling, causing plugs to foul, and consumption to go up? Would be worth taking a look at them, straight after a run up to temperature. Since fuel is always relative to air, how's that fed into the engine?

Triple filtered

iTrader: (26)

New plugs fitted. No difference.

Pinks with walbro fitted.

markjmd

iTrader: (11)

Those are pretty big injectors for a classic, I'd still bet on some serious over-fuelling going on (or not enough air). The only question is what's causing it.

Triple filtered

iTrader: (26)

It has been mapped to run these

Butty

iTrader: (2)

What do you mean "pinks with a walbro"? What pump type doesn't "pink"?
So when first mapped, did it cold start OK then and have acceptable fuel use?
Injector seals come to mind.

Triple filtered

iTrader: (26)

Pink STi injectors.

The car was already mapped when I got it.

No fuel is leaking from the injector seals

mikey30

i would have said temp sensor but you have replaced it...right???

Butty

iTrader: (2)

Pull the plugs out after leaving overnight and see if one (or more) stinks of fuel.

STi pink injectors fit a phase 2 engine? Is it a transplant engine from a newage car?
Perhaps a full description of all mods might help a bit with diagnosis.

Triple filtered

iTrader: (26)

Changed coolant temp sensor today.

Started first turn of the key.

Changed lambda too, old one was thick with soot (could scrape it off)

Started no probs and no stink of petrol. Taking it a good run now to heat up and see what sort of MPG I get now.

Happy days!!!

joz8968

iTrader: (13)

Let us know how you get on...

Triple filtered

iTrader: (26)

Took the car a run and it was as sweet as.

Revs are still up and down on tick over now and again so I'll be changing/cleaning the idle control valve next. Also wondering if its just a very dirty map its running as my standard JDM STi was like that.

Couldnt check the MPG as the immobiliser jammed on and had to reset it with the keypad. One thing after another just now

joz8968

iTrader: (13)

Yeah clean ISCV and also check the pipework that goes from it to the turbo inlet pipe - make sure it's not got crud in that could be restrictive (unlikely though). After cleaning the ISCV, using a thin art sable brush, mark with some white paint both sides of the its flange's positions relative to the IM - then you can try adjusting it about a bit (without losing the OEM reference position)...