Kinda started...

[donagain1]

Decided to turn my garage into a temporary cabinet finishing shop the other day. This dictated parking the '85 911 Cab 3.2 in the driveway alongside my daily driver. Except for rare occasions like this, she never (well, seldom anyway) goes outside to play in the rain and is always garaged overnight. Due to the PITA associated with drop cloths and cabinet parts all over the place, I kept her outside for three nights in the rain.

The be-atch is now making me pay for the indignity. Went to put her back to where she belongs, and she started fine, idled well for a scant couple minutes, then hiccuped, coughed, sputtered, and finally gave me the silent treatment. Attempts at restarting failed, though periodically sounded like she was thinking about it, but ultimately I was just cranking her to no avail.

I pulled and inspected the distributer cap, finding zero evidence of moisture. Fuel tank is about 1/8th full, though I suppose there could be some moisture in there, but it'd be hard to imagine why. The engine compartment is pretty much dry, except for drips beneath the A/C condenser grill. I pushed her back into her side of the bed, closed the garage door, left the engine compartment lid open and the driver's window open. My thoughts here being that if damp air affected the DME, it's connectors, or the relay, allowing it to sit in a nice dry environment might allow for her to forgive me and rev her engine. Generally though, if she continues to give me the same cold silent treatment that both of my ex-wives did, I might have to similarly resort to giving her some gifts. Anyone have an idea where to begin if the magic doesn't spontaneously happen?

[DRACO A5OG]

Did you smell fuel at the tail pipe? If yes, verify that you are getting spark and the plugs. If no fuel smell try swapping the DME relay.

If there is no spark, check the OHMS on the Ref/Speed sensors.

[donagain1]

Thanks for the prompt reply, Draco, you're usually pretty good help with these things. All good tips for sure, but after letting her stew for a while in the garage she decided to forgive me and kicked over with a roar after I twisted on her key. I won't say "problem solved" because it wasn't exactly, still being an unknown that just isn't happening any longer. I'll start the search for something which might have been moisture sensitive, but as is usually the case in these domestic disputes, I'm not exactly sure what I did wrong.

BTW, how's the weather down PV way? Are you guys still experiencing Jerry Brown's drought? He says we still are up here in NorCal, despite the rivers being swollen, reservoirs full, and a snowpack in the high Sierras that should last until April or May.

[SpyderMike]

My similar problem wasn't so much as water under the cap, but it was water making its way down the plug wires into the wire socket boots at the cap and shorting out each plug wire. This happened just about anytime I left it out in the rain. I put a small bead of sealant around each wire to boot interface and problem was solved. I noticed the new wires I installed last year are already have sealant there.

[DRACO A5OG]

Brother Don,

Yeah, I will not be surprised if Comrade Premier Brown still says we are in a drought, he needs to stay in control no matter what it takes. LOL. Heck even our local man made lakes are over filling now :-o.

Good to hear, SpyderMike may have something there, if the spark plug ports were filled with water it could cause havoc for you, it probably dried out now. Check out the plugs and put some di-electric grease around the rubber boots of the plugs and plugs them as well.

I know when I wash my engine from time to time she will act funny until I get her to operating temps then she will be well again.

[Quicksilver]

Originally Posted by SpyderMike

My similar problem wasn't so much as water under the cap, but it was water making its way down the plug wires into the wire socket boots at the cap and shorting out each plug wire. This happened just about anytime I left it out in the rain. I put a small bead of sealant around each wire to boot interface and problem was solved. I noticed the new wires I installed last year are already have sealant there.

This is where prepping the wires becomes so important. (I use this same method on everything I have that has plug wires.)

Before installing the wires pull each boot toward the end of the wire and rub a bit of dielectric grease around the mating area then pull the boot back into place. On connectors where you can't really move the boot just distort the rubber back while greasing with your finger. This will make a perfect waterproof seal between the wire and the boot.

Use a Q-tip to grease the inside of the boot where it will contact the plug/cap then you can install the wire. If you have a correct seal you should have some trouble getting the wire to stay on because the air trapped under the boot can't escape and it tries to pop it off. On the distributor cap you can pinch the side of the boot to 'burp' some of the air out. On the plugs they will usually stay because they are clipped onto the plug but rocking the boot from side to side can help some air escape.

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To the original problem...
Parking the car outside shouldn't be any real stress for the mechanical systems in a Porsche. I wouldn't be surprised if you find the failure is unrelated to the abandonment outdoors.

[ischmitz]

Ah - intermittent issues. As you said you haven't fixed anything and the nature of the beast is that'll rear its ugly head again when you least expect it. So I would still try to get to the bottom of this. In order of likelihood this can be:

- DME relay on its way out -> get a spare, use it and see if it resolves the issue
- One of the FW sensors (or both) -> when it happens you'l get no spark and no fuel. However, it was sputtering so this would point towards the speed sensor only:
- DME itself -> when it happens you likely will have fuel but missing spark or weak spark.
- fuel pump (controlled by DME relay). If the fuel pump can't make sufficient pressure either because it's on its way out or the DME relay is intermittent it'll make the car cough and sputter and almost start but it won't run. I have seen fuel pumps doing this. One day they run perfectly fine and then they produce low pressure and suddenly they work again. And the cycle repeats.

The DME relays are known to fail. Some of them intermittent too. It is a good idea to have a spare and they are less than 30$. So that is a no-brainer to get one if you don't have one already.

Depending on the age of the FW sensors I would go ahead and replace these. They are not terribly expensive if you get the BMW version and there are numerous examples where the original ones are failing due to hardened insulation cracking, etc. So if you don't have a record of yours being replaced before probably a good time to do that.

Ingo

[donagain1]

Again, good tips one and all. I tried to pull straight up on the plug wires at the cap to pop one and check for evidence of moisture/corrosion. None of them would budge, so I'm guessing there wasn't any dielectric grease smeared on there the last time the cap was replaced... or maybe there was and it's aiding in maintaining an airtight seal. Definitely something to take care of, as well as the other stuff when I finish with my current incarnation as a cabinet man and return to my life as a crappy golfer/occasional 911 tinkerer. For the present though, I'll just keep on running her occasionally when the weather is dry. Thanks again to all!!!

BTW, Ingo, FW sensors? It's an acronym I'm unfamiliar with. Are you talking about the speed/reference sensors that plug in kinda beneath the heater blower on the left side?

[ischmitz]

yes, FW for flywheel.

One more thing. If a 3.2 sits for extended periods of time (weeks) the injectors sometimes stick close. This will make for an initially very rough running or no-start car. You can tao the injectors with a screwdriver handle while an assistant cranks and that usually brings them back. Others use a 9V block battery to shock them open. As the engine sputters to live they eventually free up and run fine.

That's one of the reasons you'll find these cars need to be driven regularly to run smoothly.

Ingo

[donagain1]

OOOH... dang Schmitz, you may be on to something there! Given three days in high humidity because of the rain, there may have been some sweat suit up inside the fuel tank because the level was low. This may account for why she fired right up if there was good gasoline in the fuel line that got pushed into the rails first, then when dodgy gas arrived the injectors started to act up because of it. Later, after sitting a while they freed themselves up... maybe some injector cleaner run through them might help, unless it's a no-no with these engines. I'll research it, but for now I must go help Tom Brady get ready for the game today.