old gas, wth did I do(stupid)..help

marty79

marty79

Well-Known Member
Joined
Nov 24, 2013
Location
Newton, NC
yeah go ahead slap me now
so yeah I'm stupid apparently. I needed to dispose of some old gas i pulled out of a jeep and well I put it in my suburban TBI thinking it would burn it out no problem mixed with some premium...well it burns but starting in the cold morning just didn't happen...like none, zilch, nada, ran like a turd holy hell starts all weird sounding and clappy till it clears up with RPMs.
so poured good gas down the TBI got it running and literally ran it till it cut off.
Poured in 5 gal of good gas last night about 8 when it died, started and ran fine. This morning no start, sounds like before all weird and clappy lol. SO what now...

In my defense (lol), I've bought tons of jeeps over last 20yrs that have sat forever to fix up and sell, they had bad gas too and never had this kinda issue with them so I guess I figured the SBC wouldn't either.

Is it because the TBI has injectors so far from the combustion chambers vs jeeps (regular EFI) having injectors right on the chambers so that's why it's giving me issues?
 
my next thought is to fill it up completely with new gas and "should be good" since I ran it pretty much empty but just making sure I'm not overlooking something. thanks for help.
I ran fine btw the whole time with the old gas, just starting in the mornings was very very rough otherwise you wouldn't have known except for the smell.
 
I have seen old gas that wouldn't burn, not sure how the molecule breaks down, or if the ethanol just holds that much moisture in the mixture.

All that being said, if you are sure the tank was completely empty when you put good gas back in, I would bet you fouled up the injectors and your spray pattern doesn't give you enough atomization of the fuel to fire off at start.

If you didn't get the tank empty, the old gas and water would be at the bottom of the tank and you might still be fighting the same issue (i.e. the engine stopped running because it was out of FUEL, not because the tank was EMPTY).

You could have fouled up an O2 sensor I suppose, try unplugging the O2 and see if there is any change.

At a minimum I would dose the tank with a heavy concentration of your favorite cleaner (chem12, seafoam, gumout, lucas)
 
shelby27604 said:
At a minimum I would dose the tank with a heavy concentration of your favorite cleaner (chem12, seafoam, gumout, lucas
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I put 2 lucas ones and 1 seafoam in the old stuff which really didn't seem to help with the starting issue.
Your right about when it ran out, most tanks have crevices so when it ran out, I'm sure there's still a little here and there in it. I'm just trying to figure out do I suck it up and drop the tank now with only 4-5 gallons or would filling it up all the way with 35gallons be good enough to mix with what little tiny bit was left in the tank? then it would suck to drop the tank lol
 
The volatile components in gas will evaporate over time, which is most of the problem that you're having. There are a lot of different compounds mixed together, and some evaporate a lot faster than other. The ratio of those are what makes summer blend gas and winter blend gas different. Combustion just doesn't work well without all of those volatiles.

If you have 4-5 gallons of old gas in the tank at the moment, I would pump it out with the fuel pump or a siphon pump.
You should have no problem diluting the small amount of remaining old gas with new gas, but I would put some fuel stabilizer in it (Startron or whatever) to help bind up any water that may have collected in the tank and may get disturbed.
 
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Fabrik8 said:
you have 4-5 gallons of old gas in the tank at the moment, I would pump it out with the fuel pump
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It had but that's gone. I put in 5 gal new gas now but still starting issues..so at this point I'm trying to figure out do I fill it all the way up to really mix the last bit that might be in there or did something foul out/get messed up for cold starts? Thanks
 
Change the fuel filter, fill it up with fresh gas, and run the hell out of it.

It's not rocket surgery.

Don't dump old gas in your vehicles.
 
I would attack it like this.
1. Verify the tank is only filled with clean/fresh fuel (pump it dry, drop it, jam a screw driver into the bottom and JB weld it shut...your choice)
2. Toss a fresh fuel filter at it
3. Verify cranking fuel pressure (someone will chime in with correct TBI pressure for starting)
-If pressure is good, I would think the injectors are gummed up....I have seen it happen on Vortec and LS engines with bad gas
-If pressures are no-good....might have roached the pump running gummy gas or water through it.
4. (And this is the most important step)....don't put old gas in vehicles, unless it is into the tank of the dude that stole your girlfriend in high school.
 
shelby27604 said:
step)....don't put old gas in vehicles, unless it is into the tank of the dude that stole your girlfriend in high school
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Lol thanks I needed to laugh good now
 
tknopp said:
How much did you really save by trying to use the old gas after having to buy 2 bottles of Lucas and 1 bottle of Seaform to correct your issue?
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Wasn't trying to save money, but use it up to clear my gas can lol. Lesson learned for sure
 
StretchASU said:
Old shitty gas in a vehicle when it was known to be old shitty gas. Why is this a thread?
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In my defense as stated, never had issues running it in jeeps before but this TBI don't like it lol
 
And now, questions about a 14 bolt set up wrong, Jerry Springer is going to come in here in a minute and pat the hands of all the little retarded kids, telling them that a 30 will handle a 40 and it's your parents fault.

I'm not going to hell yet, but it's warm here.
 
I did the same dumb thing several years back. Fill it up with 93 octane and dump a couple bottles of fuel treatment in and just run it.
 
drkelly said:
I did the same dumb thing several years back. Fill it up with 93 octane and dump a couple bottles of fuel treatment in and just run it.
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Weather you did it or just making me feel better, lol, I feel better already
 
I may have/had used so old or questionable gas, in my old CJ, or lawn mower. But, not in anything fuel injected!
BTW, I like "Mechanic in a bottle"! Works great for lawn mowers, anyway!
 
Mechanic in a bottle does work good. I poured a bottle in my generator before Florence and it was purchased in 1994...I've never been in the carburetor.
 
marty79 said:
Weather you did it or just making me feel better, lol, I feel better already
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True story. My van was shaking it was running so rough. Lights that I didn't know existed on the dash were lit up and flashing. I thought I was screwed.
 
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