The vehicle was towed in as a crank/no start. Customer said they were driving and the vehicle started to run rough and make noise. They pulled over shut it off and it would not start.
After being on it for a few hours, I am certain the fuel is contaminated with some diesel. Also the vehicle has a full tank of gas. The fuel smells funny(not outright like diesel, but definitely not like gasoline either) and is extremely oily. I suspect it is a gas/diesel mix.
So a few questions:
1. How can I tell definitively if there is diesel or not?
2. Is there a test kit/empirical data of some sort I can present to the customer?
3. Will this necessitate parts replacements, or can the system be cleaned?
I replaced the spark plugs with new ones and am trying to start the vehicle with a Motor-Vac machine. It still wont start and the cylinders are flooding. Though now the fuel smells like pure gasoline. Is it possible the diesel could have damaged the injectors? I pulled the fuel rail and cranked the vehicle and the fuel from the injectors looks to be more of a spray rather than a mist.
Take a fuel sample, pour a small amount on a concrete floor. Light it and let it burn out. Diesel contaminated fuel will leave an oily film on the floor. diesel will generally not hurt gas injectors.
I don't know that it would definitively prove its diesel, but you could use a fuel quality test kit to check specific gravity. I'd think if it were way off of what it should be that would give you a bit more evidence. Does it look green or red like either of the 2 diesel dyes? I'd imagine the most definitive tests require lab equipment but hopefully some of this helps. My main question is how in…
Yes you are right diesel fuel pumps have larger nozzle but here at our area in kansas, some have small nozzle for pickup trucks ,cars . If he is able to see were they got the last tank of fuel see if others have same problem. Want to think years ago was a station that got the wrong fuel in to it's tanks , and had to pay out to get lot of cars , trucks fixed .
The quickest and safest way to determine if you have diesel mixed with gasoline is to take a fuel sample from the vehicle. Put a few drops of the fuel on a paper towel. Fan the paper towel back and forth through the air to accelerate the evaporation of the gasoline. If you are left with a wet oily spot, you have diesel fuel in your gasoline. If the spot evaporates and there is nothing noticeable…
Over the years i’ve seen a lot of this. One time a transport truck put diesel in the gas tank at a local station and it messed up a lot of vehicles. Some of them ended up at my shop. I just unhooked the fuel line and used the fuel pump in the tank to pump the bad fuel out. Then I put in good fuel in the tank. Used a little carb cleaner to get the car started and then it was ok. Never had to…
My own brother did this to his 2005 Grand Cherokee. Determined it was diesel using the method Matt mentioned above. Poured a bit of a sample on the floor and lit it up. Gasoline burned off and what was left wouldn't re-light. At that point I jumped out the fuel pump and emptied the tank, filled it with fresh gas and new plugs and it unhappily fired up after several attempts. Been fine ever…
I tried burning the gas on porous concrete and both the known good and suspected gas left behind a somewhat oily stain. That was inconclusive. I then tried it on a solid (painted) surface and the known good left behind a dry,scorched mark. The suspected gas left behind an oily mess. Almost looks like motor oil. Not sure if its diesel,but definite contamination.
The proper way to test this is to measure the specific gravity of the fuel... They sell test kits set up for this. Diesel is .8 to .9 ish specific gravity and gasoline is .73 ish. Here is the type of tool I am talking about. bradyinstruments.com/products/fuels… Another option is to put in a clear container to see if it separates.
My 1st response... talk w/customer, give my suspicions and ask how soon after last fueling... how was fuel paid for and do they have a fuel receipt. Whatever was pumped will be on receipt. And to verify you can always run a substitute gas supply can to see if starts. I didn't read anything about smoke. If it's burning diesel there should have been evidence of smoke... altho a lay person may not…
I use this tester. if the fuel is diesel and gas mix it will float lighter than diesel. Seperation is not likely to be a quick process Esprecisely post agitation. I agree with the burn if the fuels were separate but mixed will be pretty tough to tell. FYI most of the cases I have been involved with usually get referred to insurance due to the cost involved in the repair. Please post the ending.
My old shop used to do diesel clean outs for enterprise RAC. 9 times out of ten there was no problem after we drained the gas tank and tried to clear lines as best as possible. we changed plugs, poured in gas and They smoked like hell for a while and usually cleared out.
I recently had a no start on a 2010 Caddy. When the bad fuel sample burned, there where a lot of bubbles in the bottom of the sample and the bad burning fuel would "spit"
Must have had a lot of water in it.
Thanks Marlin, that makes sense.
We used cardboard for many years wet it let the gas evaporate fan or blower to speed it up if you want. The diesel fuel will stay behind when the gasoline evaporates
Hello, Rudy I've had a lot of experience with contaminated gas. - Simple test: collect a fuel sample on the end of your finger. Hold your finger up to the sun. If your finger evaporates dry, it's probably gas. If it's shiny, it probably has some level of diesel contamination. - The problem with specific gravity testing is that we don't know exactly how much diesel fuel is mixed with how…
On this vehicle, you turn the key once,then the vehicle will continue to crank on its own accord for several seconds in an attempt to start. I did this,repeatedly. Several times. The vehicle would not start, and the cylinders would be flooded with fuel. I surmised that perhaps there was too much residual diesel in the combustion chamber,preventing spark propagation. I spent a couple of hours…