Mike's 1991 Subaru Legacy SS

[kimokalihi]

Mine ran out of gas and I found someone to get some gas for me and put a gallon in and only filled up about 12 gallons. So 13 and I was out but when I'm on the empty mark it takes about 11.5 gallons. Even at 25mpg that's only 287.5 miles. I doubt you'll get that good of mpg. Maybe but you're using 4.11's right? You'd have to be cutting it much closer to running out than I'd be comfortable with.

[kimokalihi]

I get 22.5 mpg with 4.44's and diving mostly country 50 mph roads filling up on average 11 gallons I'm only getting 225 miles on a tank.

[mike-tracy]

Kimo, you know we have 60 liter/15.9 gallon tanks right? If you can't drive another 50+ miles without running out, you have a capacity problem with your tank, or with the pump getting all of the fuel in it.

[randomiam]

I get pretty poor gas mileage but are you sure you are calculating it right Kimo? Reset the odometer after your next fillup and then next time around, divide the miles driven by the gas it took to fill back up to get the actual number

Our tanks are supposed to be 15.9 right? I've noticed that you still have a good 3/4 gallons after its on E-- 22mpg x 15.9 = 350~ miles range

[kimokalihi]

I know. What could cause that problem? How many gallons do you put in when you're on E? I just assumed that was the desin of the tank.

[kimokalihi]

I get pretty poor gas mileage but are you sure you are calculating it right Kimo? Reset the odometer after your next fillup and then next time around, divide the miles driven by the gas it took to fill back up to get the actual number

Our tanks are supposed to be 15.9 right? I've noticed that you still have a good 3/4 gallons after its on E-- 22mpg x 15.9 = 350~ miles range

I know how to properly calculate mpg. I think you didn't see where I mentioned I'm on empty and it only takes 11 gallons. I ran out of fuel and it only took 13 gallons.

[mike-tracy]

When my fuel light comes on I have just under 3 gallons left. I give myself 50mile before I 'have' to fill up, and there's always a gallon or more left at that point

[kimokalihi]

Well that makes sense then. I wonder why I don't get that much fuel before I'm out? The tank came from an NA legacy but it should be the same.

[kimokalihi]

My fuel light doesn't even come on. I saw it right before I ran out of gas. Like within a minute or two of running out. And it went off before it ran out of gas.

[mike-tracy]

Yeah not saying that my light comes on the same as everyone's. But mine does come on when its supposed to.

[rob]

I asked Alphius his opinion on the problem, and based on my description he thinks it could be the cam or crank sensors. When he mentioned that, I remembered that the cam wire was spliced, and the ground wire goes straight to the body. Apparently a previous owner solved a grounding problem that way. I also accidentally tore off the plug for the crank sensor when I pulled the engine a while back, but I had soldered it back with shrink rap, so I'm not as worried about it.

Mike, do you still have one of your cam sensor wires grounded to the body?

-Rob

[Alphius]

Yes, he does. It's going to be fixed soon though. I personally think that the janky wiring on the cam/crank sensor wires could be the cause of the problem. The ECU loses tach pulse when it happens, so it is probably losing sync due to noise on the cam/crank lines or something similar.

On fuelchat, I easily achieved 300+ on a tank with my Turbo Legacy. All city driving usually got me 23mpg and highway got me 29 pretty easily. I was able to put in 14.5 gallons at the most, but I never really had the balls to push it any further and never ran out completely.

[rob]

Ok, that is a problem. The (-) signal of the cam/crank sensors is not ground. Both + and - should be directly connected to the ECU pins.

[Alphius]

Exactly. Hence why I told him to fix that a long time ago; he pulled some un-molested wiring out of a junkyard car to put in hopefully very soon.

[mike-tracy]

I will, I will. I have this Sunday off and plan to do it then. Previous owned claimed not to have 'rigged' the wiring like that, and the owner previous to that was Matt Monson, so I can't exactly blame them at this stage lol

[rob]

Yes, he does. It's going to be fixed soon though. I personally think that the janky wiring on the cam/crank sensor wires could be the cause of the problem. The ECU loses tach pulse when it happens, so it is probably losing sync due to noise on the cam/crank lines or something similar.

Ah ok. I misunderstood the previous comments about fixing as general wiring cleanup. This is more than just cleanup

Also keep in mind that both sensors require shielded wiring, with the shield grounding at the proper ECU pin.

Mike, I think you guys are headed in the right direction. I personally wouldn't waste any time thinking about other possible causes until you have this fixed. It is likely the source of your troubles.

-Rob

[mike-tracy]

Thanks Rob, I'll post how it goes on Sunday.

[Legacy777]

So this morning I bought some starting fluid for testing. WD40 and Brakecleen weren't flammable enough to pinpoint the source of the leak. Well turns out the driver side injector rails weren't seated properly in the manifold. I had a real bitch of a time with them last night, and ended up lubing the seals between the rails/manifold but apparently that wasn't enough.

So I seated them properly, and the huge hissing sound is gone, as is the horrible idle. My car can boost again Still have the full load/5k rpm spark cut, but the car is more than drivable. So long as I don't plant my foot I'm fine. Set mbc to 12psi till I get that one sorted out.


****
OK I'd like to explain how the car evacuated all it's fuel as it's something I've never experienced or read about, as well as added hours to how long this ordeal took. The passenger side rail was fully installed, and I had the driver side rail bolted down, but the rear fuel hardline wasn't connected. I turned the key on to 'ACC' for about 30 seconds, smelled fuel and realized I had pressurized the fuel system, so I turned the key off. I noticed the unbolted side of the rail leaking some fuel, but I figured that without the pump running it would run out of pressure and stop flowing shortly.

We ate dinner, and when I went back to the car, sure enough the rail wasn't leaking any more.... So after a crap ton of testing because it wouldn't start (including testing the injectors) Adam said, you sure you have fuel in there? I said yes, I filled up full yesterday, and have driven 145 miles (about half a tankful). Well, for some reason, the pressurized fuel system created a siphon effect that went on to drain the entire tank. Fortunately the car was outdoors and there was no real fire hazard. I ended up putting around a gallon of "mystery fuel" (from a gas can lying around) plus 14.8 gallons from the gas station.

I guess the takeaways would be:
-Don't work on a fuel system, in the dark, or when tired.
-Never, ever prime the fuel pump when a fuel line or rail is open.
-Always have a backup car in case you can't finish the job.

Mike,

Always make sure you use plenty of lube!


Regarding your fuel adventure.....so you're saying that you drained out close to 5-6 gallons? Was there a massive puddle or spill under the car? 5-6 gallons of gasoline is quite noticable? Also, the ECU does not get powered on with the key in the ACC position, only when it is in the ON position. Unless the wiring has been bastardized, which hearing about your other issues, might be the case, the ECU shouldn't have powered on with the key in the ACC position.

[Alphius]

The car was parked over grass (in my front yard), so the fuel went into the ground.
He turned the key to the "On" position, which primed the pump and started the siphon and then we went to dinner shortly after so nobody involved noticed it was still draining.

[beatersubi]

Thats a lot of fuel to siphon though a leak. Luckily most of it likely evaporated. But let us know how that spot on your lawn is after a week.

[kimokalihi]

Haha. Did it smell pretty badly when you got home and climbed out of your car? Do you have a well or city water?

[mike-tracy]

The car had been outside all afternoon with the hood open, so just our footwear smelled like gas.

[Alphius]

Yeah, my shoes smelled like gas pretty bad the next day.
I am on city water.

I will update you guys on the lawn after a week or so.

[cj91legss]

Im curious about the lawn as well...

Sent from my SGH-T989 using Tapatalk 2

[kimokalihi]

Unrelated but if you pee on the same patch of grass for a couple weeks it dies. This is from experience. Lived in a building with no plumbing for 3 years and working nights I would just pee outside rather than hastling with keys in the dark to get into the house.