So just an idea,
It may fall off and drift to page 9999 in no time, but maybe people care.
Who has car questions?
Never changed your oil?
Unsure which fluids are best\should be used?
Been told a 'Job is hard' and think you're being ripped off?
Want advice\help on a DIY?
Discuss it here!
I'm a bit of an oil and fluids nerd myself, so feel free to ask... things.
I'm actually going to start this one off myself with a story, and to see if anyone can think of any bases I haven't covered...
To cut a long story short (it's still long...); working on a Stock Turbo'd EJ20;
Both banks on the passenger side are super lean.
Both banks on the Drivers side are fouled (but have colder plugs in them; 7's, and IMO subaru already specs one range colder than needed... so i'm not too worried here)
The drivers side proves the rail (at least on that side.....) is getting sufficient fuel pressure, as there is only one shared feed (otherwise we'd have a full lean condition, not just 2 cylinders)
First thing we tried was temporarily clamping the fuel return hose, which helped a fair bit. (I only wish I had a fuel pressure gauge, because those spiked levels are scary, lol)
We changed the fuel pressure reg (which could be blown through albeit slowly, by mouth pressure alone). And that helped a little.
I cleaned up the plugs and re-gaped them to 0.76mm. Yes, subaru specs 0.85, but just from experience I've found EJ's idle way smoother with a smaller gap. Timing is probably ever so slightly off in the tune to meet emissions.
Cracked open the fuel tank and checked the pump.
Someone had installed a Walbro 255 (nice....) and left the stock 'subaru negative fuel capacitor' setup hooked up. Its an oddball thing, so we removed the stock wiring and put the genuine Walbro wiring kit into the harness\pump.
Noticing the pump was less than 2 years old, and the fuel sock pretty clean, we threw him back in.
Next was injectors. One friend was certain; 2 injectors going at once would be 'near impossible' but the crud we found inside it were scary. I wish I got pictures.
we're talking large grain of sand deposits stuck to the spray, and 1mm thick crud around the entire injector in general (never good...)
The inside of the rail looked clean now though; so I'd say its buildup over the 15 years of running.
Some new injectors helped majorly. But we still had somewhat (< understatement) rough idle.
Injectors show similar Ohm's (good) and the wiring loom seems to have various identical reading on both positive and ground, between the 'good' side and the bad; so the loom seems A-OK.
Turns out, some numpty had the old style 'dumb' Idle air control valve at maximum adjustment. Calming that down restored warm idle near perfect.
So we're left with a car that hates life when cold.
We're yet to be able to inspect the plugs yet, its only done 20km (too soon, junior).
Anyone have any ideas of what we've missed?
I'm thinking the lean condition could be during idle only, because you tend to hear Boxer engines pretty clearly when they ping at high revvs.
Also that always open IACV that we re-adjusted lets its air in on the 'lean' side we found.
I'm running out of ideas to smooth this bad boy out entirely.
They only have a single Air\Fuel sensor, so that's the next trial. Subaru's are happy to have it unplugged and just run a little rich.
The Air Flow meter is a known working unit from a car that got a Speed Density tune and 'didn't need it'.
The only extra thing to add is that the engine does have 5~7psi lower compression figures on that side of the engine. So it could be leak down mechanical leaning.
But I'm thinking, to be that lean, we'd be smelling fuel in the oil and it's holding up pretty well.
Besides the A\F (o2) sensor, and the MAF, can anyone think of what we've overlooked?
Not a bad night of testing for 4 hours and 2 cans of coke :)
And feel free to ask questions! basic shit, tire pressures, fuel types, Octane ratings, whatever. Open the floor :)
Edited by Master_Scythe, 08 May 2015 - 11:09 AM.