240SX '94 - pouring gas out the muffler

[honeybus]

Hi.

I have a '94 240SX up on jack stands and dirty fuel is seeping out of the rear seam of my muffler.

The car has not fired off in over a month; it has not even turned over in over a month (bad battery and bad starter)

I just replaced the battery last week and noticed that I had this fuel leak from the FRONT of the 240SX. It was facing nose down in my driveway.

I pushed it into the garage and put it up on four jackstands, with the nose now pointed upwards, and I notice the fuel is now coming from the rear seam of my muffler.

In the past 18 hours, I have captured 4-6 ounces of dripping fuel in a clear plastic container. I had the container replaced this morning, and when I get home after 8 hours, I will see how much is still dripping out.

Note: while I did replace the battery, I only had it connected for 30 minutes while I tested that the starter was truly bad. Then I disconnected the battery, and it stayed disconnected.

What would cause fuel to pour into the exhaust pipes?? Could it be that the fuel is pouring into the cylinder(s) and then oveflowing out some exhaust valve into my exhaust system??

What would cause such a massive flow of gas?? Constantly pulsing the fuel injectors ??

And what would constantly pulse the fuel injectors, even without the engine turning over?? A constant ground to the Fuel Injectors??

And where would this 'constant ground' be coming from??

Thanks

Barry sends
Modified by honeybus at 8:29 AM 7/24/2007

[180fan]

you could have a good sized leak near the rubber hoses at the fuel tank. Isolate where the fuel is coming from. There is not a constant flow of fuel in the system, but gas does turn into vapor and can pressurize the system that way, especially in these warmer summer days, and cause fuel to leak from a hole you've somewhere. Try opening your fuel filler cap to help relieve that built up pressure in the tank. then try to set it fairly level and find where the fuel is coming from that way.

[honeybus]

Thanks, 180fan.

This fuel IS coming from the muffler. Black gas!! There is NOTHING dropping on the muffler / tail pipe, so it is coming right from the 'front', through the exhaust system.

In May 2007, when mechanics were playing with the 240SX, trying ot get it started and then having it run for only 5 secs before it flooded out, there was plenty of raw gas coming out of the tail pipe. Like, P L E N T Y ! ! ! Raw gas and heavy white smoke.

And dirty gas would leak out from the front, under the engine area.

I first thought a hose was broken, but is definately coming through the exhaust system.

But since the 240SX had not even turned over in the past 4 weeks, where did this new fuel in the exhaust system come from, if not from an over flow from an open exhaust valve in a stationary (non-rotating) engine, where the cylinder was flooded so much that the gas came out the open exhaust valve!! (Battery replaced; starter not replaced; key on for a short time to prove starter is bad; results = gas on the ground!!)

Apparently, with the ignition turned on but the starter not turning over, my fuel injectors are running a constant flow because of a 'ground' problem.

But where is this 'ground' problem??

[cnichols]

Everytime you turn the ignition "on", the fuel pump primes the fuel system so that there is pressure when you attempt to start it. If you've been doing this constantly, it pressurized each time. How it's getting into the exhaust, I don't know, but it doesn't sound good.

[honeybus]

Thanks.

I am going to find the fuse that controls the fuel pump and pull that fuse.

Right now, I have one FI removed for replacment, so I have no line pressure.

Next, I want to check my compression and then I want to see if I am geting a solid signal or a pulsed signal to my fuel injectors by installing a home made NOID light at the fuel injector harness. I hope to see 'pulses' and not a steady light.

http://www.autozone.com/servle...9.jsp

http://www.autozone.com/az/cds...s.htm

Man, talk about taking a walk in the dark!!!

[honeybus]

I haven't had a chance to do the compression check and NOID light test.

I did look at the 'liquid' that I captured which was dripping from the muffler for the past 4 days. It doesn't appear to be gasoline. More like 'oil'!!!

I have four plastic containers with the liquid and I am going back to mechanic 'Choi' to get an idea of what this liquid is.

Four days ago, it was dropping at a rate of one drop per 12 seconds. Now it has almost stopped and each day there was a decrease in the amount dropped. The four containers have less and less liquid, and the last three containers were changed at 07:00 each morning. (the first one had only 18 hours captured, yet it is more than double the volume of the next container with 24 hours captured.)

Besides, if it was pure, dirty gasoline, it would have evaporated at the slow rate it is now dropping and not left any liquid residue.

If it is not gasoline, then it is back to the drawing boards.

[180fan]

got a picture of the mystery fluid?

[honeybus]

got a picture of the mystery fluid?

Lunch time, and I just got back from mechanic 'Choi' and the consensus is 'gasoline'...

So I threw away the four containers.

I should have about a tablespoon or two in the container under the 240SX when I get home, but I am going under the assumption it is dirty (carbon impregnated) gas from the exhaust pipes. It should be so small a volume I feel fine throwing a match into it.

I will post updates.

(three finger) Barry sends

[240sxmech]

first things first you need to pull the injector rail up with the injectors adn pressurize the system and se if any are leaking with out starting the car . I bet you a hundred dollars the fluid is coolant running ou tof your exhuast because like you said when it was running it had white smoke that is coolant mixxing in your combustion chamber .blown head gasket.

[honeybus]

first things first you need to pull the injector rail up with the injectors . . .

Thanks, 240sxmech You are absolutely right. The new mechanic I saw yesterday said that would be one of the first things he would do.

Unfortunately, pullin the fuel rail, or even pulling the valve cover off the engine are not within my mechanical skills at this time.

I bet you a hundred dollars the fluid is coolant running ou tof your exhuast because like you said when it was running it had white smoke that is coolant mixxing in your combustion chamber .blown head gasket.

240sxmech, the coolant has not gone down as might be expected, but I think I can check for a blown head gasket, and that is one think I will do. I don't think so, though...

See update below

I pulled FI #1 because it was the last one of two FIs I had recently replaced.

This was pulled a week ago - FI #1 was missing its pintle cap. The pintle cap probably got ingested. I bought a new FI and it sits on my workbench, ready for installation.

I took a piece of fabric and stuck it down the empty FI #1 hole.

The small piece of fabric came back SATURATED with gasoline!!!

This engine was not run or even turned over in the past month!! Only last week did I put a fresh battery in it to prove that the starter was bad. This fuel got down (where ever 'down' is) there testing a new battery, but not turning the over!!

((The pictures are small sized.))

The cloth is FIRMLY attached to this piece of hanger wire..



Now it is out of the FI hole, shown with a clean piece of blue towel paper.



This is how much was on the fabric. The fabric was dripping fuel.



The gas completely saturated the paper towel.



Next step is to pull the spark plug from cylinder #1 and see if gas is down the cylinder.

Anybody taking bets?!?!?! ((The compression is normally 182 - 187psi, so it is possible))

((From the experience with removing FI #1 when it was inoperative, I will not even consider pulling the two older FIs. FI#2 may come out easily, though..))
Modified by honeybus at 8:46 AM 7/27/2007

[honeybus]

Modified by honeybus at 1:00 PM 7/27/2007

[honeybus]

* * * * *

Update:

My pictures were pulled from the web site. Now I have to find some place to host them.

Sorry for the missing pictures..

* * * * * * * *

Well, I put a stick down the spark plug hole and I got fuel at about 1 1/2 inches of mark.

Stupid question, but does the 240SX fuel injector spray directly into the head?? when I put that wire through the FI #1 hole, is this going right into the head.

I am familiar with the air cooled VW bus, and the VW bus FI fires off into an intake manifold, and the intake valve open and ingests the air/fuel mixture. The VW fuel injector fires off four times for one cycle. All four VW fuel injectors fire off at the same time.

I was attempting to siphon off the fuel mixture in the #1 cylinder, but I guess as I was poking around, all the fuel finally went past the rings.

I checked the spark plug holes for #2, 3, and 4. They were normal, no liquid.

OK, the condition now is:

1 #1 fuel injector is out of its socket. Its rail is bare. 2 all other fuel injectors are disconnected from the harness3 the Fuel Pump 15amp fuse is pulled (is there only ONE fuse??)4 I have a fuel pressure gauge after the fuel filter5 all spark plugs are removed6 the battery is disconnected, and has been disconnected for over a week.

I connect the battery.

I try a compression test on #3. I turn the engine over 8 times. Compression reading is 250.

250 ?!?!?!? Damn, did I break something??

I go back for a second try. I turn the engine 8 more times. Compression reading is 160.

But wait!! There is oil all over the engine compartment?!?!? It has got to be coming from the spark plug holes....

I try covering the spark plug holes with a yellow fabric. It works a bit, after one or two turns, but #4 starts blowing oil/gas out the spark plug hole, and gets the porous fabric pretty wet.

So I layer some four pieces of blue paper towel over the open spark plug holes and then lay the yellow fabric over the paper, to keep them from flying off.

The engine didn't like this!! The blue paper and yellow fabric blew off the valve cover, and a gas/oil mixture flew all over the front and fenders of the 240SX. What a mess!! The blue paper squares were saturated with the gas/oil mixture.

Here are the pictures:

The blue paper towel is marked off in 1/2 inch increments



The stick from the spark plug hole picked up just about 1 1/2 inch of fuel



I put the stick in the FI #1 hole where the yellow fabric was in the earlier post, and I got almost 3 inches measurement.





* * * * * * * * *

I was getting oil/fuel blowing out my spark plug holes when I tried to do a compression check. I tried four times with the compression check before I tried this to get an idea how much was blowing out the spark plug holes.



I laid down four squares of the blue paper towel, so I could get an idea which cylinder was doing what.



I covered the paper squares with the yellow fabric, a very porous fabric



The cylinders spit out oil/fuel and saturated the paper and then blew the papers, yellow fabrics, and oil/fuel mixture all over the left side engine compartment



Barry sends

Modified by honeybus at 1:28 PM 7/27/2007

Modified by honeybus at 1:31 PM 7/27/2007

Modified by honeybus at 1:33 PM 7/27/2007
Modified by honeybus at 5:57 PM 7/27/2007

[94_240sx]

I have some experience with fuel system/FI before and all I can think of now is bad lower o-rings. If your lower oring is broken or torn, pressure from fuel pump is strong enough to flood gas into the cylinder. If I were you, I'd remove injectors and replace o-rings first since it's one of those fairly cheap try.

Check your coolant. If you see any white stuff mixed, you have a blown head gasket.

Oil in the cylinder might be because of bad valve cover gasket.

[honeybus]

I guess this is the final update.

My pictures were pulled from the web site I was using to host them.

Yes, my #1 Fuel Injector had a bad O Ring. Also, the pintle cap became lost, so I went out and bought another fuel injector. I just buttoned everything up an hour ago.

Now I am putting wheels back on and it is either going to work . . . or not!!

Bottom line: I drained FIVE GALLONS of oil/fuel mixture from the oil drain plug.

I hope with the new FI and fresh oil / filter, I will be ready to go.

Bye

Barry sends