I have been trying for over 3 months now to find the problem I have which is the cold start idle problem,running verrrrry rich,misfire under WOT and rev hanging.

Just to recap on what has been done

Maf changed 3 times
2 x water temp sensors (ECU sensor)
2 x oxygen sensors
2 x ICV
1 x TPS
Vac lines changed and checked
Timing Checked
Air filter changed
ECU changed 3 times
Sprayed around intake manifold with card cleaner to test for leaks.
New Coil packs and plugs

Just to recap again on the problem cold start idle is very low 400rpm tries to stall every 10-20 secs once warmed up ides at 700rpm but all the time running very rich and have rev hanging when pulling up at junctions etc and under heavy WOT and boosting 1.2bar I am getting misfire.

What else can it be?

 

Im guessing that by all the work that has been done its not showing any engine management fault codes? Have you joined the wires to get the fault codes? I know im probably well behind where you have already been.....

 

No codes at all I wish there was though :-)

 

Stuck injector maybe?

If possible, you could get a similar car and measure under the same conditions:
MAF voltage
Injector duty cycle
AFR with wideband

After comparison with your car you would have an idea what's wrong. For example:
If your AFR is different but the other values are the same, this it's probably an injector, you could then unplug injectors while the engine is running and see which one produces the biggest difference.
If the MAF and AFR are out, then the issue is the MAF or an unidentified leak.
If the IDC and AFR are out, then possibly an ECU or other unidentified sensor problem.

 

intake manifold gaskets?

 

sounds like you have a vac leak somewhere? has the throttle body been tampered with at all?

 

Sorry is it a classic - Try a fully charged NEW battery then reset ecu then about 10 mile off boost drive- mines was doing similar this sorted it right out - bad cell in old battery was causing havoc

good luck
iain

 

New battery installed last week and ecu reset.

Vac leaks all checked none present.

Did do some testing yesterday with a like for like car and the only difference was that my fuel pump was working much harder the sound was twice that of the other car.

 

I have just had a thought could it be the fuel regulator that is at fault?

 

Which MY and what mods??

Are these all new or used items, OE or aftermarket??

How far have you checked, have you had the complete timing cover and crank pulley off??

What ECU's have you used/tried??

What plugs did you fit, and what did you gap them too??

Could be the butterfly in the throttle body sticking due to it being gunked up. Could be caused by over filling the engine oil and excessive blow by contaminating the I/C and ducting.

Where is your oil level sitting, on the 'o' or on the '<' of the dipstick??

How have you concluded that you are running rich all the time??

 

Pulled plugs and all were sotted up big time and full economy is about 10mpg off boost.

 

What were the Used parts that you fitted?

 

I took them straight off a running car and I know this as I took them off myself.

 

??

Then the oil is over filled and as such could be attributing to the problem. It should be at the top 'o' when full.
Check the inlet tract and the T/B butterfly for contamination. It can also cause boost issues and lower the octane of the fuel.
BTW, what fuel are you using??

 

I only use v power

I will double check the oil the oil tomorrow.

So what do I have to do.

I do have boost issuse when I at WOT and hitting 1.2bar I get what i would call it (boost judder).

 

As you are remapped and running a little more boost/power, i would be running NGK PFR7B's at 0.65mm as the 6's can be a little soft and blow out at WOT.
Re-check the oil and drian down to mark. Remove the T/B to I/C hose and check for residue around the butterfly and in the I/C, clean with carb cleaner. Put some carb cleaner through the BCS too, from top to bottom.

 

sorry whats BCS?

 

Boost Control Solenoid mate.

It is on the drivers side turret on the Impreza, don't know about the TT Legacy. You may need to consult a Haynes or similar for location and operation.

 

OK cool is in the passenger side wing on a Leggy thanks

 

Update today i had a fuel pressure test done and theses are the results:

At Idle
Vac Line attached = 40psi or 2.76bar
Vac Line detached = 55psi or 3.8bar

Looking though my Haynes manual my idle pressure should be for Turbocharged engines:
Vac line attached = 34-40psi
Vac Line detached = 38-44psi

Looks a little high to me so what could cause this if there is a problem?

 

have you got an aftermarket dump valve fitted? also just to check, get some brake cleaner and spray all around the inlet/throttle/vac pipes etc ,this will highlight any leaks.

 

I would suspect the stock fuel pressure regulator,as the 55 psi value is way to high.
I know in the USA they sometimes dent the FPR to raise fuel pressure when IDC's are a bit on the high side, maybe your's got dented accidentally.