Car with 2 year old gas, running rough..

[fleabag]

I've got a LS400 that I've had parked for about 2 years now b/c I didn't need to drive it until yesterday. Well first off it started pretty rough and then from then on, it likes to buck, vibrate and etc. under hard acceleration and when I have it in D, at a standstill and then have the brake partially depressed so that the car moves but is being slowed, but it does ok under very very light acceleration. I ended up getting a check engine light stating that I have an air fuel ratio lean malfunction. The tank was 3/4 filled before I started driving it yesterday and I'm wondering what could be causing this issue. The issue sort of gets better as the car warms up but otherwise cold vs. hot starts, the car runs the same.

The car ran perfectly fine before I stopped driving it about 2 years ago, I turned on the car I believe one year ago to see if everything is fine and keep it somewhat lubricated, didn't notice anything odd of the sort.

So I'm thinking it could be the following issues:

1. Bad/old Gas?

1. water in Gas?

1. something clogging air intake? (there were mice/rats inside of engine bay at one point)

1. fuel injector got dirty/broke?

Even better, it appears this car doesn't have a check engine light/code for missing/not working injector! Does 2 year old Premium gasoline really act this badly? Or is it just water? I dunno but I would like to hear your ideas!

I pulled the first code, 25 this morning before I ran the car, so that would mean that code was generated when the car was at running temperature. Just ran the car this morning for a short drive, turned it off and checked again, got two more codes, this time Code 24 and 26 as well.
Code 25:Air-fuel ratio lean malfunction


So when the car is started up, it's running rich, when it's at running temperature or under heavy load I suppose, it's running lean?

Thread closed due to necro post.

Zenmervolt - AnandTech Moderator

 

[boomerang]

Pull the top off the air cleaner housing and check for what the mice hauled in there. They may have built a nest and/or hoarded food in there.

They like to chew on wires too. You could have a hell of a mess on your hands.

Bad/old gas - check

Water in Gas - check

You've hit on all the high points. That old gas can't be helping the situation. Start with the air cleaner.

Edit: Draining the old fuel is going to be a chore. If you can get it to run decently, I would instead, top off that tank several times to see if you can get enough fresh gas in it to dilute the old stuff enough. I would throw a can of injector cleaner in the tank too. It may need a professional injector cleaning, but it would be an inexpensive thing to try. It may function to deal with the water in the tank too. Read the can, if not add some drygas or an equivalent product.

You'll want to change the oil and filter too. There will have been lots of condensation in the crankcase as well as the gas tank.

 

[fleabag]

Looked at the air intake, looks relatively clean, doubtful this would be the cause. One thing I noticed is that the exhaust smells rich yet it's giving a lean code. The engine feels almost as though not all cylinders are firing, leading me to believe that the car think's it's lean b/c not all cylinders are firing so it over enriches the mixture. Here is a site with all the codes: http://www.lexls.com/tutorials/intro/codereading.html

 

[boomerang]

Originally posted by: fleabag
Looked at the air intake, looks relatively clean, doubtful this would be the cause. One thing I noticed is that the exhaust smells rich yet it's giving a lean code. The engine feels almost as though not all cylinders are firing, leading me to believe that the car think's it's lean b/c not all cylinders are firing so it over enriches the mixture. Here is a site with all the codes: http://www.lexls.com/tutorials/intro/codereading.html

Well if the airbox is free of mouse flotsam, it's time to move on. Until you can get fresh gas in there any diagnosis is useless.

You say it doesn't seem to be running on all cylinders. That would be the first thing to deal with now, IMO. Get some fresh gas in it. When you pop the gas cap and stick your nose in deep and take a big sniff, what does it smell like?

You could be getting a lean code because you've got gummed up injectors. Injectors that aren't spraying any fuel at all. At this point your whole fuel system needs to be gone through. Fresh gas, new filter, injector cleaning, the whole works.

 

[Demo24]

Well you need to do a couple things. First of all get the oil changed, then get any other fluid topped off, might as well do a coolant flush while your at it. Then basically run the car as much as you can. I suggest running it until you get to 1/2 a tank, then fill up, and then keep adding more fuel when it gets just around that mark again.

Gas breaks down after awhile, and 2 years is really much to long to have kept it in there. I would not have even bothered with it if I knew it was that old, I would have tried to empty the tank somehow. Also I would not have started or driven it without at least an oil change.

and if it doesn't run better after some fresh fuel then its time to start with more drastic measures.

 

[boomerang]

Originally posted by: DEMO24
Well you need to do a couple things. First of all get the oil changed, then get any other fluid topped off, might as well do a coolant flush while your at it. Then basically run the car as much as you can. I suggest running it until you get to 1/2 a tank, then fill up, and then keep adding more fuel when it gets just around that mark again.

Gas breaks down after awhile, and 2 years is really much to long to have kept it in there. I would not have even bothered with it if I knew it was that old, I would have tried to empty the tank somehow. Also I would not have started or driven it without at least an oil change.

and if it doesn't run better after some fresh fuel then its time to start with more drastic measures.

I'm sorry but when bad advice is given like this I must voice my disagreement.

Don't worry about changing the oil at this time and the advice of flushing the cooling system is - well - just bad. It's not the slightest bit related to this problem.

Running the car trying to burn through bad gas, when it's not running on all cylinders is a recipe for plugged catalytic converters. Especially a lengthy amount of time as would be needed to burn through that much gas. My understanding is that they are extremely expensive for this car. DO NO DO THIS!

 

[Fern]

That old gas is likely a problem.

You may have water in it as well (condensation). The lower the tank was on gas (i.e., more air in it) and the more the temperatures fluctuated the more water you may have.

Fern

 

[Demo24]

Originally posted by: boomerang

Originally posted by: DEMO24
Well you need to do a couple things. First of all get the oil changed, then get any other fluid topped off, might as well do a coolant flush while your at it. Then basically run the car as much as you can. I suggest running it until you get to 1/2 a tank, then fill up, and then keep adding more fuel when it gets just around that mark again.

Gas breaks down after awhile, and 2 years is really much to long to have kept it in there. I would not have even bothered with it if I knew it was that old, I would have tried to empty the tank somehow. Also I would not have started or driven it without at least an oil change.

and if it doesn't run better after some fresh fuel then its time to start with more drastic measures.

I'm sorry but when bad advice is given like this I must voice my disagreement.

Don't worry about changing the oil at this time and the advice of flushing the cooling system is - well - just bad. It's not the slightest bit related to this problem.

Running the car trying to burn through bad gas, when it's not running on all cylinders is a recipe for plugged catalytic converters. Especially a lengthy amount of time as would be needed to burn through that much gas. My understanding is that they are extremely expensive for this car. DO NO DO THIS!

uh, oil breaks down after awhile as well. It hasn't run in 2 years, that oil is not up to the task of lubricating that engine anymore. Running it with that old oil in it is simply a recipe for disaster. The coolant works just the same way. And its always a good idea to change especially after sitting for so long.

Now if you noticed you changed position all of a sudden to attack me. I suggested he attempt to get as fresh gas as possible in there to start diagnosing the problem. Yes, it may be more serious such as clogged injectors. But you won't know that until you either a) take them out or b) try running it on new fuel. Now to find out the latter it needs to be run, hence having crap oil in there is going to be awful for the engine. It's a hellva lot easier to try running it to cycle fuel.

 

[fleabag]

Well I've emptied the tank and filled it up with 5 gallons of fresh premium fuel, still have the same issue. I find it very hard to imagine that a fuel filter would get clogged when the car is sitting. Before I nearly completely drained the gas tank, I got a look inside and it was very very clean.

 

[Jeff7181]

How long did you run it? Draining the tank won't remove all the fuel... you'll have a gallon or two left in the tank and there will be fuel in the fuel lines/rails. You could try fuel system cleaner too... chances are the injectors have some buildup that may be causing problems.

The alternative... drive it or tow it to a shop and pay them a few hundred dollars to fix (or at least diagnose) your problem to avoid ruining the engine and costing you a few thousand dollars.

 

[fleabag]

Originally posted by: Jeff7181
How long did you run it? Draining the tank won't remove all the fuel... you'll have a gallon or two left in the tank and there will be fuel in the fuel lines/rails. You could try fuel system cleaner too... chances are the injectors have some buildup that may be causing problems.

The alternative... drive it or tow it to a shop and pay them a few hundred dollars to fix (or at least diagnose) your problem to avoid ruining the engine and costing you a few thousand dollars.

Well when peeking inside the 22.5g tank, when I saw an inch of gasoline and checked the fuel gauges, it said I had like an 1/8 of a tank left of gas. So I drove the car around some more until it was below the E line and then filled it up with 5 gallons of gas, then drove around some more. The only thing I can currently think of to try is driving around with the MAF disconnected and checking the resistance values of the Sparkplug wires, distributors, and checking the coils, unfortunately on this car, doing the latter is going to be quite an invovled process, one that would appear to be very necessary.

 

[Farang]

You got to know when to hold em, know when to fold em,
Know when to walk away and know when to run.

..to a mechanic

 

[fleabag]

Originally posted by: Farang
You got to know when to hold em, know when to fold em,
Know when to walk away and know when to run.

..to a mechanic

the problem is, it's an LS400 and I don't want to spend mega $$$$ having him NOT repair the vehicle but instead, throwing a lot of parts at it, that is something any old idiot can do. What I want to do is diagnose the issues with the car like you're suppose to, checking fuel pressure, resistance readings, etc.

 

[fleabag]

Did anybody on this forum know that fuel filters will prevent water from going through them? I haven't been able to find too much information about this but from what I've read, a fuel filter will not let water pass which could in a sense clog the filter making it difficult for fuel to get through. Assuming the bad gas issue is resolved, what I want to know is, if the fuel filter is not letting water pass, is the solution as simple as removing the fuel filter, drying it out and putting it back in? I ask because I'm thinking the fuel filter isn't bad, it just has water in it and therefore all it needs is to get the water out. Since gasoline is heavier than water, any water that gets in the tank would automatically sink to the bottom, right? Pour a 1/4 cup of water in a 20 gallon tank and all of the water will sink to the bottom, right?

 

[dud]

Gas attracts moisture. Drain your tank and eplace with fresh gas.

 

[SithSolo1]

Any reason you didn't just drive it a few miles every so often? I mean we've had an STi since 2004 with only 6800 miles on it that stays parked 99.9% of the time, but we run it every so often, put in fresh gas, and change the oil.

 

[fleabag]

Originally posted by: dud
Gas attracts moisture. Drain your tank and eplace with fresh gas.

I siphoned out as much gas as I could, then drove around on that last bit, filled it up again, still had issues.

 

[StageLeft]

2 year old gas = terrible. I am convinced that major problems I used to have with my lawnmower were because I left the gas in without any stabilizer over the winter. 2 year old gas is garbage.

In the case of my lawnmower, I had to literally clean the carburator 5-10 times, it was getting to where I had to do it every time I wanted to use the mower. Even after removing the old gas I think residue and crap from the old had holed up in the motor and it took a long time to get rid of it. It's possible you've done the same in your case. Also possible I don't know what I'm talking about, though.

Any reason you didn't just drive it a few miles every so often? I mean we've had an STi since 2004 with only 6800 miles on it that stays parked 99.9% of the time, but we run it every so often, put in fresh gas, and change the oil.

Yeah, you definitely want to be doing that! Wow 6800 in five years or so is nothing!

 

[fleabag]

Replaced fuel filter yesterday, we'll see if this helped the problem or not. I blew on both fuel filters and found that the new one (tried first) was not very restrictive at all, I mean I could breathe through that thing quite easily. Blew through the other one and found it a bit more restrictive, but not a whole lot, the one thing I did notice however is the old one was much heavier than the new one. Does a fuel filter have to be really restrictive to cause an issue or can a little restriction be enough of an issue? Another thing with the replacement of the fuel filter was that like 2 gallons of gas came out, removing any additional water that could've been inside of the gas tank or hanging out before the fuel filter..

 

[dud]

You can syphon all the gas you want but if you have water in the line you'll still have problems. You should never let gas sit for too long (don't ask me how long "too" long is).

Good to hear that you have replaced the filter. Run it for a while and see if it improves.

 

[LTC8K6]

Have you tried a can of HEET?

 

[nakedfrog]

Originally posted by: dud
You can syphon all the gas you want but if you have water in the line you'll still have problems. You should never let gas sit for too long (don't ask me how long "too" long is).

I believe conventional wisdom puts it at six months.

 

[exdeath]

Two year old gas = pumping glue though your injectors.

 

[LTC8K6]

Sta-Bil might help too.

 

[Squisher]

First, extend your left hand and slap the back of it hard with your other hand, saying, "bad, bad, car owner."

Then get an oil change (and maybe a coolant flush).

Change that fuel filter. Then, I'd throw a couple of cans of injector cleaner in that 5 gal. of good gas that you put into that 1/8 tank shellac and drive it until it was almost empty. Then fill it new gas. Then remove every injector and do a full cleaning and change the fuel filter again.

But, then again I'm cheap. I don't like mechanics either unless they're working for beer.