My 1986 420 SEL 190,000 miles has been sitting for over a year. I keep it as a spare car in case my other car breaks down or needs repair. The last time I put gas in it was about a year and a half ago. I tried starting it the other day and had no luck. Just to make sure there was gas in it I poured about three gallons of fresh gas in it. Still no start.

Here is what I have done so far: some fresh gas, listened to see if fuel pumps are working(yes), shot starting fluid down throat of intake and it started right up but only for a second or two. I did this two or three times and it started every time.

I am assuming that this test would basically eliminate a major electrical problem? I also cracked the gas line from the fuel distributor to the cold start valve and there was fuel. I did not take it off but a small amount came spewing out and then I tightened it back down.

My questions are these: Could the gas have turned so ransit that it is no longer ignitable? Could the fuel system be clogged from setting so long without use? If so, should I start under the hood (injectors,fuel lines etc) and work toward the gas tank or start at the gas tank and work forward toward the engine? Should I drain the tank and put new gas in it?

The car has always started even after setting for some time but this time it doesn't even give a hint that it wants to start w/o starter fluid.

Even though I have owned the car for about 15 years I am still pretty much a rookie when it comes to MB's. If this was my 57 chevy I would'nt need to ask so many questions.

I know that you all have the answers because I have been reading lots of the threads.

Thanks Any help appriciated

If it starts on starting fluid then its for sure a fuel problem. I would bet on bad gas or varnish. Could be a plugged up fuel distributor or a stuck plunger or something. I wonder if you could get it started on starting fluid and keep it going a little bit on it....if it would get going and run on its own fuel after a minute of being helped out.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

My neighbor has a gorgeous classic car anno 1958 as a collector car but he sometimes takes it out for a drive, just around the block. He told me that a car should be driven at least once a month.

__________________
1996 E320 since 1/16/08, 171K miles as of Feb 2011

---------------------------------------------------------
1989 300CE - R.I.P. Dec 29 2007
Other MBs (sold): 1992 300E-24 - 1979 350SLC - 1984 230E - 1990 300CE

I agree, I have our Rav4 sitting around and I run/drive it at least a few times a month to keep the gas fresh and everything moving.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

More important for transmission seals etc. in an old car than most anything else.

__________________

Gone to the dark side

- Jeff

Agreed. Gotta keep those seals moist or they will be leaking like crazy.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

I keep this artical around to show my customers....


Does Gas Go Bad?
By ERIC PETERS, AOL AUTOS

Does gasoline really go "bad" if you leave it unused for a period of time? Some people are convinced this is just another urban legend, and that people who worry about "old gas" and spend money on fuel stabilizer are wasting psychic energy as well as cash.
But in fact, gasoline can degrade over time. That can lead to a number of problems, ranging from hard starting, to rough running, to no starting at all.

Here's Why
Unlike crude oil, gasoline is a highly refined product brewed to a certain chemical composition with very specific characteristics. One characteristic of gas is volatility, a term used to describe how easily and under what conditions the gas vaporizes so it can be efficiently burned in your car's engine.
" The most highly volatile components in gasoline also tend to evaporate over time. "
The most highly volatile components in gasoline also tend to evaporate over time. As they do, the remaining fuel's volatility and ability to combust properly degrades. The less volatile the fuel, the less effectively it burns in your engine. The result is diminished engine performance. Your engine may still start and run, but it probably won't run as well. The good news is, once the old gas has been consumed and the tank is topped off with fresh fuel, the problem should cure itself. Evaporation of volatile compounds can be limited by making sure the gas cap is secured tightly. For the same reason, be sure all portable gas containers are sealed tightly as well.

A More Serious Problem: Oxidation
Hydrocarbons in the gas react with oxygen to produce new compounds that eventually change the chemical composition of the fuel. This leads to gum and varnish deposits in the fuel system. These deposits and impurities can clog up gas lines and filters, as well the small orifices in a carburetor and the even smaller orifices in a fuel injector. Removing these deposits can be expensive and your vehicle may not run at all or run very poorly until they are removed.
Water Contamination
Condensation can form inside your gas tank and lines from heat cycling. Fuels such as E85, which have a high concentration of ethanol alcohol, may be even more susceptible to water contamination, as ethanol likes to draw moisture out of the surrounding air. Water contamination can be a problem at gas stations with light traffic due to a slightly different kind of heat cycling. The underground storage tanks experience increases and decreases in temperature. This can cause moisture to form and contaminate the fuel. When you fill up at such a station, you're pumping in the water along with the gas. Such low-traffic stations may also have other contaminants in their underground storage tanks, such as rust. They are best avoided when possible.
Water, of course, does not work too well as a fuel in an internal combustion engine. It will cause hard starting and rough running until it's purged from the system. It can also contribute to internal rusting of the gas lines and tank. The resultant scale and small particles can create a true nightmare, sometimes requiring the replacement of the gas lines and tank at considerable expense.

" Oxidized fuel often turns darker over time and may even smell sour. "
You can reduce the chances of water contamination by keeping your car's gas tank as close to full as possible, especially if the vehicle is going to be left idle for an extended period.

How Do You Identify Bad Gas?
One way is to eyeball it. Oxidized fuel often turns darker over time and may even smell sour. You can check stored gasoline by pouring some into a clear glass container and comparing it side-by-side with known fresh gasoline. If your old sample looks noticeably darker than the fresh gas, you have strong evidence the gas has gone bad.

How Long Does it Take for Gas to Go Bad?
That depends on a number of factors. For one, it's hard to know how old the gas you just bought actually is. It may be fresh from the refinery, or it may be a month old already by the time you top off your tank. Some gasoline is mixed with better or more oxidation inhibitors than others. It's a good rule of thumb to avoid leaving gas in your tank or a storage container for more than a coupe of months, if you can avoid it.

And if You Can't?
If you know gas will sit in your tank or a storage container for a couple months, then it's a wise move to buy some fuel system stabilizer and mix it in with the gasoline. Do it before you put the vehicle into long-term storage or before leaving your lawn equipment fuel containers sitting for the winter. The stabilizer helps prevent oxidation, the biggie that can turn gas into garbage that gunks up your system and leads to expensive repair work. Using fuel system stabilizer for extended storage is preferable to draining the tank and leaving the system dry. This can cause rubber hoses, gaskets and seals to dry-rot and crack, possibly leading to leaks and even a fire. In addition, a dry system can expose the insides of metal fuel lines and your gas tank to air and moisture, which can lead to or accelerate the formation of rust. Fuel system stabilizer is not a cure-all and it doesn't last forever. It must be mixed with fresh gas before the vehicle is stored, not added to already old gas. It can slow down the oxidation process and keep gas fresh for as long as 12 to15 months. If you're going to leave the vehicle parked for longer than that, you may want to drain the tank and refill with fresh fuel before returning the vehicle to service