Hi all:
Here is my odyssey.
Mi emissions/safety inspection sticker expired, hence I drove to NYC for the tests.
(car is registered there, I am near Raleigh, NC). Great drive, 7 1/2 hours.
Test is done in a dynamometer, with a sniffer in the exhaust.
GOOD NEWS
Results:
HC limit 0.80 Car 0.29 (passed)
CO limit 15.0 Car 2.7 (passed)
NOx limit 2.00 Car 1.21 (passed)

Drive back yesterday - BAD NEWS
New Jersey - Blizzard conditions, but no problems.

Delaware, right after the toll for the bridge, car goes into limp mode.
(400 miles away from Raleigh, snowing, sleet, freezing rain, 29F, windy and Sunday)
Car has no response to gas pedal, cruising at 5 mph on I-95. Pull out at nearest exit
stop at Mobil gas station, pour some STP gas treatment/water removal, and fill up
with super+. Car idles like crap, all of a sudden, it is fine.
So I decide to take my chances, run like a rocket, go up the ramp to merge onto I-95
south. Right before merging, try to accelerate - NOTHING -.
Holy S@#$!!! there is a truck coming at what seems 100 MPH in the right lane, and I am
limping at 5 MPH. I pressed that gas pedal so hard, I thought my foot was gonna go thru
the floor. Nothing. Truck is flashing every single light is has (like 1000 of them).
His horn sounded like it was in my headrest. My foot is on the floor 1,2,3 seconds
(feels like an eternity) truck is approaching fast!!!.
God takes over and my car redlines, takes off faster than I have ever seen it.
WOW!!, it is freezing outside, windows open (29F) and I am sweating bullets.

Maryland went without problems.

Washington DC - Virginia (beltline I-495)
Doing 70 MPH center lane. Try to switch lanes to pass on left. No response, economy gauge
is red line, but car is actually losing speed. Oh NO!!
Wiggle my way to right lane, 65, 60, 55, 50.....5 MPH with no gas pedal response.
Stopped in shoulder, idles like crap. Wait 10 minutes, press gas pedal and nothing.
Well, I will limp until next exit (so I think). Let the car roll, try to accelerate,
it stutters, hesitates, a couple of thumping/bopping sounds coming from the engine
(NOT BACKFIRING, from air intake?). It "catches full power" releases, catches, releases
and finally takes off like nothing ever happened.
It did it once more in Virginia (40 miles from NC border)

North Carolina - Flew by at 85 MPH without problems.

By the time I got home (12 hour trip), I was more stressed than Saddam Hussein. Perhaps
like Osama must be feeling right now.

I just drove the car 80 miles to Fayetteville, it appeared to hesitate after filling up.
But just for a second.
Now I turn to you for help.
WHAT IN HEAVENS WAS THAT ABOUT?
What should I look for?

__________________
1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car
609 Certified

Check your fuel pump and relay.

Fuel pump relay looks good, it is 1 year old.
The pump sounds normal (normal hummm).
Took the car during lunch time, at a stop light noticed some hesitation. It made that strange bopping sound coming from engine compartment (not backfiring). As if the intake plate opens and slams close, and opens again. Bop, bop.. and runs fine.
Idles OK. I am at a loss.
I wonder if water could have gotten in the intake somehow, but it all looks dry now.

__________________
1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car
609 Certified

UPDATE:
Apparently the problems were moisture related, since all the strange gremlins happened during snow, sleet and rain.
I just drove another 300 miles (Fayetteville to Asheville, NC) without any problems (dry & sunny skies).
Something came back after 10 months thought, the oscillating idle (600 to 1100 RPM). With an occasional sticking at 1100 RPM.
Engine bay is very dirty with road salt. I will try to clean the idle control valve next weekend (this fixed the oscillating idle before), remove the potentiometer and evaluate it.
May be is time for a new pot, unfortunately I did not remember to check the duty cycle as the problem was actually occurring.
That would have pinpointed the problem in "real" time.
Will update.

__________________
1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car
609 Certified

The problem has not reocurred.

I cleaned and lubricated the ICV.
Oscillating idle is gone.

I am convinced the problem was caused by water in the system.

No more updates.

__________________
1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car
609 Certified

Don't experience it much in SoCal, but sounds rather like icing to me. Maybe you should check for the source of water entry.

Liked the truck episode description. If you change careers, I would look into screenwriting for adventure films.

Steve

__________________
'91 MB 190E 2.3
'08 RAV4 Ltd 3.5
'83 Lazy Daze m'home 5.7