Super lean

[paroxysm]

So after sorting out all the problems with my gf8 wrx wagon, i moved onto a sti. More problems haha

Felt super quick, faster than my mates evo 4. So i wanted to get it dyno'd to have some bragging rights.

They only got up to 130kw on the dyno before shutting it down, and told me the car was running super lean and they didn't want to rape it as they where too scared it would blow something.

The AFR was between 14 and 15 the whole run and they told me that it should be 11-12.

I'm planning on buying a walbro fuel pump and a fuel pressure regulator and then check the AFR after that.

If that dosn't work I'm going to look engine management as my ecu looks like a standard version 3 ecu.

Am I on the right track? And is there anything else that can cause running lean that I should look into?

[rex-leggy]

i would get the air flow meter tested first. it could cause the problem .

at least it did for me.

[sultan]

lol sounds like my car when i first bought it many years ago. it had a possum link in it, and i think the dude had bigger injectors when it was tuned and put in factory ones when he sold it. i ran it up on a dyno and they pulled out at 130kw too around the same afr as yours

[paroxysm]

 sultan said:

lol sounds like my car when i first bought it many years ago. it had a possum link in it, and i think the dude had bigger injectors when it was tuned and put in factory ones when he sold it. i ran it up on a dyno and they pulled out at 130kw too around the same afr as yours

Any suggestions?

[sultan]

have a look at the actual logic board inside the ecu case, it could be an aftermarket one.

otherwise, yeah start checking for faulty bits of gear. stuff i imagine could have an effect on afr: (as above) afm, fuel pump, vac leaks, injectors, etc

is there a boost tap/controller? how much boost is it running?

[Pappu1]

Checks for leaks etc

My mate Daniels suby was running lean and turns out had few leaks on intake and that sorted the issue

[paroxysm]

Yes has a manual boost controller.

Was running 13psi when i dynod it. I don't trust mbcs so i left it at 13.

Will have a better look at ecu in the morning

[Stoffa]

I would just run wastegate pressure untill you find the problem

[paroxysm]

Yea i am now. I just didn't crank the boost up before as Ive seen the consequences of mbc's in mates cars.

[Ninjr]

Dude, best thing to do ...

Go see Nick, get yourself a link g4 ... whack it on the dyno, tune it, power gains + safe tune = you winning lol

problem solved ... that or youll just be spending the money on a rebuild soon enough anyways haha

peace

[paroxysm]

Thats the plan in the long term. But tight on money right now so if i can get a cheap fix then i will till i can get link

[paroxysm]

Walbro is in and cars running sweet. Still gotta check the AFR though.

[EJ20T]

If the car was lean during the entire run id take a guess that its not the fuel pump, as if that was the case it would likely get leaner with increasing revs and prob develop a miss at high rpm and load. sure it doesnt have a air leak between the afm and turbo? bad afm or bad fuel reg, split vac line etc

[paroxysm]

Ye gonna do everything i can think of before dyno. But walbro is good regardless

[EJ20T]

have u checked it doesnt have a air leak, pointless changing stuff just to end up fixing a silly leak

[paroxysm]

Yea I have. But if it has nothing to do with the fuel system im going to need a fuel pump anyway for later

[Disruptz]

Possible leak in the intake? bad 02 sensor? bad maf sensor dirty/clogged fuel filter

Try if you know someone with same model etc try plugging in there maf sensor, see if that will fix it.

[evoetr]

Hey mate is this your new ride, my ex? lol I hope not lol

 paroxysm said:

Yes has a manual boost controller.

Was running 13psi when i dynod it. I don't trust mbcs so i left it at 13.

Will have a better look at ecu in the morning

If so get rid of mbc and go for a aftermarket computer, (possum link plus) etc

as your engine is one of a kind. Prodrive heads and cams from the late and great

Colin Mc'Crae Legacy's days. The block is a RS closed deck, balanced crank,

forged pistons etc. It was made to produce at least 450 to 500hp with the right mods,

eg: Turbo, ecu, fuel pump, fuel regulator, injectors, surge tank, wastegate.

When i sold it, it was tuned to be running rich as it was no use in doing anything else

unless you are prepared to do the right mods to get the potental from motor. Or tuned

to be durable so you could have 200kw, 250kw, 300+kw atw, the later meaning there

are chances of things going bang sooner than wanted.

I had most things except turbo and ecu, but sold them once i had decided to sell car, got

more $$$ selling them separate than with car. With the vf32 and mods you should be able

to get 250kw atw wheels and be durable without to much stress put on internals.

You are probaly looking at least upto 6-7 grand for mods and tuning time or there abouts.

Just a gestamate on what it might cost you.

[paroxysm]

Ye it is mate, came with a mbc in. Havnt raised the boost with it. just wound it right down to wastegate pressure after the dyno day

The only thing i think thats different from when you had it is that it has a VF30 now.

Pretty much stopped driving it atm as after I read about it on Qrafs previous posts I realised its not worth risking damaging it. It's going into the mechanics this week for some tests, fuel pressure, afm, o2 sensor, basically the things people have told me can make it lean

Just put a walbro in, next is fuel pressure regulator and maybe injectors, want to get it running richer asap.

Then the plan is to pick up alot of extra work over the summer and get a link + tune.

Really don't care what it costs me, still so stoked to have it

[paroxysm]

Mechanic reckons its running rich at idle and WOT now so I think the fuel pump worked. Old one could have been dieing.

MAF and o2 sensor and fuel pressures sweet.

Now time to get it back on the dyno, check how much power its putting out as is, and what the afr is on the dyno now

[QRAF]

also make sure the air/fuel gauge has been hooked up properly and doesn't have any bends in it and the fittings at the back are sorted.

[paroxysm]

 QRAF said:

also make sure the air/fuel gauge has been hooked up properly and doesn't have any bends in it and the fittings at the back are sorted.

Ye I wanna buy a new one, its so useless

[Dv8er - FSTWRX]

 QRAF said:

also make sure the air/fuel gauge has been hooked up properly and doesn't have any bends in it and the fittings at the back are sorted.

Bends? It should be wires not pipe I would have thought.

Is it running off a Narrow band o2 Sensor? New gauge won't do jack shit then. You need a Wide band sensor ideally.

[paroxysm]

 Dv8er - FSTWRX']

[quote name='QRAF said:

also make sure the air/fuel gauge has been hooked up properly and doesn't have any bends in it and the fittings at the back are sorted.

/quote]

Bends? It should be wires not pipe I would have thought.

Is it running off a Narrow band o2 Sensor? New gauge won't do jack s*** then. You need a Wide band sensor ideally.

Wires yes. Ye thats what I meant sorry. Wide band sensor and a nicer looking gauge

[QRAF]

Sorry i meant wires but they can still fark out is all a mean

No point replacing everything if the gauge your reading is giving misinformation is all.