We have a suspicion that a car we are trying to get started may have diesel in the gas. Is there a simple way of telling? Some type of separation in a glass perhaps, or maybe something entirely different that can be added to stimulate a separation? Possibly some type of a volume displacement technique? The gas has somewhat of a sweet smell and nobody has volunteered to taste it. : )~ Thanks in advance.
testing for diesel in gasoline.
Feb 03, 2006
7 Replies
The quickest, simplest solution, if your suspicions are strong, just drain the tank and put in gas.
I had a similar problem with a GEO Metro I purchased. The seller knew that his son had put 5 gal of diesel (stolen) in the tank, thinking it was gas. The seller had tried to pump out all the diesel using the in tank pump and then added 5 gal of gas. The engine would just barely start but no power.
I got this car for $150 and towed it home. Filled the tank Full with gas, replaced the spark plugs. Ran the engine for about 100 miles, cleaned the plugs again. Runs great now and is my daily driver. To do the job correctly, I should replace the catalitic convertor. I think intially I was getting some back pressure from the fouling of the convertor but it seems to be clearing out with time and hot exhaust. I doubt that it is doing its job and should be replaced.
Don't know a easy way to test, but regular gasoline can have up to 1 percent of anything in it, target is .5 percent - and usually does (kero/jet fuel, bunker oil, etc) if it arrived by pipeline and especially if you are served by the terminals that fill up at the end of a stub line. Batch interface transmix gets blended back in. On the other hand, once in a great while you will buy regular and get all or mostly premium that has been downgraded.
No, there is no easy way to be sure.
Gasoline and diesel are ranges of Cx's. They mix. They are almost the same. Your best bet would be to determine the specific gravity of the mix. Determining the Reid Vapor Pressure would be good, too. For about $150 you can have it tested for BTEX content. There are many other tests that can be run to determine Cx range of the blend but they are somewhat expensive.
Specific gravity is easy to do with a hydrometer. Refractive index is also easy to do. Vapor pressure is a bit of a pain to do in the kitchen but isn't a huge deal.
All of these, though, will cost you more than the price of a tank of gas if you don't have the equipment handy.
Pull out a quart of gas. Put it in a lawnmower. If the lawnmower won't start, the gas is bad. Drain it out of the lawnmower and put good fuel in, then run it for a while.
--scott
Excellent idea!
Similar to what I know of a TVO [tractor vapourising oil]
Huw
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