Water In My Gas, Mystery???

[Dave Colangelo]

This has now happened twice so I figured there must be something up.

I went to move my car this evening and as I usually do I got in, started it up and let it warm up. I usually give it 5 minutes but now that its warmer out the needle lifted off after about 3 so I put it in gear and got going, get about 1000 ft. and the engine cuts out. I give it a second, let the car sit, start it right back up running fine, figured I would give it some time to warm up more, after another minute (just sitting there) the engine cuts out.

At this point Im thinking DME so i swap in my jumper and the car starts up fine. Let it sit for another 45 seconds to run, engine cuts out again. Its not the DME so I remove the jumper and put the DME back in.

Start the engine back up keep the revs on the higher side as it seems to be running better around there and get the car another 500ft (into its spot) and im sitting there for a minute and the engine cuts out again.

Now I'm getting frustrated, everything seems to be working fine, I had just driven the car 65 miles yesterday no problems what so ever and it has been working issue free recently.

I restart the engine, rev it up and keep it around 2K for a minute, then I let it settle back down, it chops a bit so I give it some gas. Play around with it for a minute and now its idling fine. Let it idle for 15 minutes with out any issue. After that I decide all is well and shut the car down.

I should mentioned I did notice a few drops as if something had kind of sprayed out of the exhaust.

Here is my theory: this stems from my recent venture into aircraft and what I have learned about moisture in gas tanks. I drove the car in the rain yesterday, and it sat outside in the rain for about 2 hours before getting it back to the garage where it resides. Today it was cool and much dryer out. I have about a half a tank of gas in the car, maybe a bit less. Is it possible that some how yesterday in the wet, moisture got into the gas tank and condensed today causing a deposit of water on the bottom of the tank? This water/moisture had to then be run out of the system and it was not until I got it all out that the car was running fine?

As I mentioned this happened about a month and a half ago however I got the car about 5 miles before it cut, then I only had to do 2 restarts before it ran fine. That was also during the very very cold January we had here in Philly so I think temp may have played a roll then as well.

Is there something else that could be up? Anyone have any experiences like this?


Regards
Dave

[emoore924]

It is unlikely that what you saw come out the exhaust has anything to do with the problem you're experiencing. Moisture/condensation seen from the exhaust, especially early on in the warm-up of an engine is normal. There are other more insidious reasons you can see moisture from the exhaust but I doubt those problems are what you're experiencing.

It could be water in the gas. In the winter, water in the form of condensation can form in the gas tank in a car that spends time parked outdoors. This happens especially in cars that are not driven a lot. Also, since it looks like you're in the mid-Atlantic region, you're exposed to ethanol fuel -- and ethanol fuel has a tendency to separate out and collect lots of moisture because of the ethanol. (Sta-bil for storage prevents this.)

So if you're not running your car a lot, and if you've had less than 1/2 tank (or so) of fuel while it has been warm and cold and warm and cold, and if you've had the ethanol fuel in the tank, you *might* have moisture in the fuel.

If this is your daily driver or if you keep the tank pretty full most of the time, I doubt you have a water-in-the-fuel problem if only because you're constantly cycling new fuel through the car.

Pull the fuel filter and see what's in there (blow through it and see if water and fuel come out, or just fuel). Then get back to us with what you find.

[Dave Colangelo]

You are correct, I am in the north east (Philly to be exact). I drive the car typically once or twice a week usually Sat and Sun but occasionally on weeknights as well. I usually run sta-bil when I park one of my cars for the season (I have a 78 911SC as well that usually gets rotated in, in the summer). Ill have to move to more regular use of sta-bil and ill see what effect it has. The warm cold warm cold issue happens here for sure as well.

Regards
Dave

[88Silver924S]

I doubt it is water in the gas, but never say never. I would look at ignition, especially the high voltage portion that affects everything such as the distributor cap, rotor and coil. I once had a distributor cap (on a '62 356B) that developed a carbon track (Google image "distributor cap carbon track") that had symptoms somewhat similar to yours. A rotor can also develop carbon tracks as can the coil tower. Wipe clean and inspect these components using a magnifier if you need to sometimes the tracks can be hard to see but the high voltage finds them especially if there is condensation moisture on the parts to facilitate the path to ground. If anything carrying high voltage is cracked that can combine with moisture and dirt to ground out your ignition.

Do you have an ignition immobilizer that is fussy? Also the connections for the reference sensors might be corroding? Is electrical contact corrosion a problem on your machine? Good luck.