Oil in Fuel - Need Advice

[sc mustang]

Unfortunately, I had some waste oil in a gas can without labeling it (yes I know).

My son decided he needed some extra gas while we were out of town and you guessed it - poured oil into his gas tank. Feels like he put maybe a cup or two into the tank.

94 GT now won't run. Will start and idle but you can imagine what the running is like. Emptied gas tank and refilled but injector system obviously isn't going to flush out because car barely runs.

Can the injectors be removed and cleaned or are they just completely ruined.

Any other advice on what to do - other than the obvious of label your damn waste oil !!!~

Thanks

 

[revhead347]

The injectors probably aren't the issue. You've got your work cut out for you. That gas tank has to come out, and be completely cleaned out. You need to blow all the fuel lines clear, and spin as much as you can out of the fuel pump. Change the fuel filter too.

Kurt

 

[HISSIN50]

The injectors can be removed and cleaned or you can try to clean/flush them while they're on the car (this is the route I'd go if it comes to it).

As Kurt noted, first replace the fuel filter and see what happens. The filter media is probably a nasty mess.

Good luck.

 

[toyman]

The injectors can be removed and cleaned or you can try to clean/flush them while they're on the car (this is the route I'd go if it comes to it).

As Kurt noted, first replace the fuel filter and see what happens. The filter media is probably a nasty mess.

Good luck.

I would concur with replacing the filter. A cup or two of oil with a full tank should not be an issue. Oil in the gas is common with two cycle engines. I really don't believe there is a need to drop the tank or clear the fuel lines. The injectors should be fine as well once the oil is diluted with a tank of gas. You mention that it idles fine so I'd suspect that the running under load problem is flow related due to a clogged gas filter.

 

[sc mustang]

Thanks for the help.

I did replace the filter tonight but it is still running very badly. The tank was nearly empty when he put the oil in it so I guess its possible the system is just too mucked up. I did pull a spark plug and surprisingly, that didn't look too bad. Any thoughts on fuel pump?

 

[HISSIN50]

I'd do a volume test if the pressure is ok.

 

[sc mustang]

Hissin,

I just went out in the garage and cut the old fuel filter in half. It looks remarkably normal to me. If the fuel filter looks normal and the plugs look normal, I guess the fuel pump is the next place to go.

What is the best way to do a flow check? Link ?

 

[sc mustang]

Fuel pressure on manifold gauge is reading 30lbs but unfortunately, I'm not sure exactly where it was before.

 

[Chythar]

31-32 is about right at idle. If you pull the vacuum hose on the fuel pressure regulator (plug the hose with your finger), you should be about 38-40psi. If so, I would rule out the fuel pump.

 

[BlownFiveLiter]

I can't imagine this would be the cause of the problem. I've used the remaining premixed gas for my snowblower in my cars every year, ever since I've been driving, so I don't have gas sitting in a can for several months, until winter comes around again. I'd probably add a few gallons of fresh gas and take it for a drive, to see if it improves, as the clean fuel circulates through the system. It should dilute the oil pretty much immediately.

Edit: Just for kicks, is it throwing any codes?

 

[sc mustang]

Thanks for all the tips. The tank was really low when the oil (very old sludgy oil) went in so its obviously plugged something up somewhere because despite changing the fuel filter and diluting the oil, it still won't run. Car was running perfect before so I know its fuel system.

I'll have to start from the fuel tank and start working my way forward. Will post after this weekend in case anyone ever does something this stupid and wants to know what I find

 

[BlownFiveLiter]

So were there any codes? I'd hate to see you go through all of the trouble chasing down a fuel system problem, and have it be coincidental that something else went awry, right around the same time as this.

 

[revhead347]

I can't imagine this would be the cause of the problem. I've used the remaining premixed gas for my snowblower in my cars every year, ever since I've been driving, so I don't have gas sitting in a can for several months, until winter comes around again. I'd probably add a few gallons of fresh gas and take it for a drive, to see if it improves, as the clean fuel circulates through the system. It should dilute the oil pretty much immediately.

Edit: Just for kicks, is it throwing any codes?

Premix oil is a totally different consistency than waste motor oil that has been sitting in a dirty container for a period of time.

Kurt

 

[BlownFiveLiter]

Premix oil is a totally different consistency than waste motor oil that has been sitting in a dirty container for a period of time.

Kurt

Yes it is. I just meant that it would dilute in the gas, so it shouldn't cause much of a problem.

 

[99FiveOh]

Yes, it would dilute in gas, but chances are good that the pump was able to pump the sludge through the lines for a little bit before gas was added.

Here's what I'd do. Pull the filter back off, put a pan under the tank. Put a little good gas in it and cycle the key. The pump will pump the fuel out and into your catch pan (most of it anyway ) and you can see for yourself when it runs clear. Once it's clear, hook it all back up, add some good 93 octane and try to run the car. Use some starter fluid if you need to help it fire up.

 

[sc mustang]

Just to clear up, the oil that was put in the car consisted of not only oil, but also grease, anti-freeze, and any other fluids that may appear in an old boat engine.

 

[sc mustang]

Continuing to post for anyone who may someday do something like this.

Pulled tank and the fuel pump/sending unit. This evolution is not as easy as it should be by the way and if anyone knows if I can get those little replacement clips for the fuel lines let me know.

Anyway, the waist oil had clearly clogged up the filter/strainer that is attached to the fuel filter. Feeling pretty good that this may be causing the lack of fuel.

Will know in a couple days when I get the thing back together. Will change pump just in case I damaged it with starved fuel !

 

[Adam95GT]

id replace the filter anyway while your under there. Id also blow out the lines while your at it to be sure. I dont think you have much to worry about on the return side.

 

[sc mustang]

Finishing up this thread for anyone searching in the future.

The filter/strainer on the fuel pump itself was it. Even with the oil diluted in the gas, it had already clogged up that filter pretty good and was preventing the car from running.

New fuel pump and strainer (30$ used) and new fuel filter (10$) and we are back in business. My son thinks its running better than before !

Thanks for the help