SAM DACOSTA

Greetings fellow Rennlister's;

Help me by discussing this scenario. Last night I drove home on the wet streets of S. California (10 miles via 405 Fwy), the car ran with no issues until I reached 1/2 mile from home, then it cut-out while driving 4 times within the last 1/2 mile from home (but was able to re-start immediately).

There was no standing water that I drove through, did not have to use wipers home nor had any issues prior to these events. I have the under tray removed, could that has allowed excess water to get into something that would cause a stall? When I got home and garaged the car, I looked into the engine compartment and it was not excessively wet.

I decided to drive it again to work today, the roads were wet, no standing water, no wipers either and it drove without any issues. What's happening here guys?
Please share your thoughts and logical solutions.

Thanks...

ilko

With all the rain you guys have been getting it's likely that you have water getting to your ignition wires somewhere. To test where the problem is start the car, get a spray bottle full of water and mist the engine bay in the dark. You may have to do both sides (top and bottom). Most likely you will get arching or sparks. That's your problem wire.

John Boggiano

My money's on a dodgy DME relay.

I once had that happen (well, I've had it happen more time than I care to remember, but on this particular occasion...) in just the same circumstamces; I was convinced water had got in somewhere.

Willie P

if the wires have never been replaced (likely), it could be time!

Rocket Rob

There have been some threads about various stalling issues. I'm assuming that this is not the classic lightweight flywheel issue. I would first suspect you have a faulty DME relay.

https://rennlist.com/forums/964-foru...gen-senor.html
https://rennlist.com/forums/964-foru...e-is-cold.html

I hope this helps.

SAM DACOSTA

I'll do this test tonight when I get home and report on it's success tomorrow.

SAM DACOSTA

Wires are knew, were replaced 4,000 miles ago with the engine rebuild.

SAM DACOSTA

LWF issue has already been solved. DME relay is a thought.

I'm going to conduct a test recommended by 'ilko' before I consider the DME relay. 'ilko' said "With all the rain you guys have been getting it's likely that you have water getting to your ignition wires somewhere. To test where the problem is start the car, get a spray bottle full of water and mist the engine bay in the dark. You may have to do both sides (top and bottom). Most likely you will get arching or sparks. That's your problem wire."

SAM DACOSTA

I'll look into the DME relay after conducting a test tonight on finding a faulty ignition wire.

jimq

is the O2 sensor factory or aftermarket? Some aftermarket ones dont seal out the water as good as factory.

SAM DACOSTA

You touched on something regarding my O2 sensor. It's factory but I had pulled it last week to install a 'Cat bypass' and now you have me wondering about a proper seal. I'll look into that as well.

911Jetta

Think back to anything that you may have recently changed on the car... BTW, what are your Cat bypass impressions?

Have you chipped your car recently?

I had the exact same problem a couple months back. Car drove great, then all of a sudden it would stall (even while driving down the road). Very minor at first, then the frequency increased. Searched RL, and thought the symptoms pointed to a bad fuel pump... started to change it... but didn't have a good feeling about it? Had it towed to my shop (was completely drivable, but worried about stalling in the middle of the hwy). They searched and searched... finally they opened the chip DME and it wasn't seated properly! When I installed the chip, I was so worried about breaking something, I didn't push it all the way in. The stalling didn't happen right after the install, so I didn't link the cause/effect at first... the other clue for me was that the stalling occurred after hitting a bump in the road.

Here's a thread I posted about it: Fuel pump dead? Man graciously finds his limit

Good luck! Now I'm off to search through all the sunroof threads...

ian89C4

+1 on the O2 sensor.

I had the same problem before. The car would just randomly stall. I did the mist test on the wires in the dark and no reaction. I ran out of options so I took it to the P-car shop. He plugged her in and it came up with a faulty O2 sensor. Replaced it and no problems since. You may also check the O2 connection in the back bottom left corner of the engine compartment.

SAM DACOSTA

The 'cat bypass' definitely has increased the audio tone of the Porsche As for performance related increase, there seems to be better throttle response but it's subjective to this car (header, exhaust, chip, air box upgrades). I've had it for 6 months and wanted to just hear it... However, my neighbor is not amused when I leave for the gym at 5:00am., so maybe it might just be a 'Auto X, DE/TT' upgrade.

Regarding chip upgrade, it was done along awhile back, so I'm not leaning to that being the issue right now. I found no arching wires last night, so I'm now looking into the DME relay. I just do not want to just start changing out everything, especially with this 'one time' scenario.

SAM DACOSTA

I also did the mist test last night but saw no arching. I will address the O2 sensor over the weekend.

Thanks..