Car shutting off while driving.

[911gt700]

I was wondering if anyone had this problem. My car shuts off while I'm driving. I've been told it might be my fuel pump or ignition switch (currently has 30K miles.) with brand new plugs. It has been upgraded to 700hp package. Any ideas before I start throwing money at it would be appreciated. Just changed alternator, battery, reflashed the ecu but the problem still exists.

thanks,

Jason M

[Loren]

:welcome:

Usually and ignition switch manifests itself as many other electrical problems. So, it absence of that I would suspect the fuel pump - assuming non of the aftermarket installed components are causing the problem.

[GT2IAN]

I had the same problem,turned out to be the MAF sensor.The standard MAF sensors seem to do this with certain types of aftermarket air filters[mine is an Evoms].My "check engine "light would come on briefly and then go off.Cheers,Ian

[wross996TT]

I had the same problem,turned out to be the MAF sensor.The standard MAF sensors seem to do this with certain types of aftermarket air filters[mine is an Evoms].My "check engine "light would come on briefly and then go off.Cheers,Ian

I have never heard of a MAF causing a car to shut down...go into limp maybe, but not shutdown...my guess is fuel related....either pump or ruptured fuel line in the tank.

[ericinboca]

I was wondering if anyone had this problem. My car shuts off while I'm driving. I've been told it might be my fuel pump or ignition switch (currently has 30K miles.) with brand new plugs. It has been upgraded to 700hp package. Any ideas before I start throwing money at it would be appreciated. Just changed alternator, battery, reflashed the ecu but the problem still exists.

thanks,

Jason M

I would lean toward fuel too. Any more color you can put around symptoms? Does it start OK? Does it shut down only when hot after being driven a lot? Does it restart easily?

[wross996TT]

I would lean toward fuel too. Any more color you can put around symptoms? Does it start OK? Does it shut down only when hot after being driven a lot? Does it restart easily?

Good point...perhaps you are starving the system of fuel because of your mods and flash...since you have a 700 package, what fuel pump is installed? Have you scanned for codes?

Edited July 31, 2009 by wross996TT

[911gt700]

Just finished the 30k service with new coils and spark plugs but the problem is still present. I always get the christmas tree(all lights) before the car turns off. That's how I know to restart the car right away. It has happened while traveling 70mph and in bumper to bumper traffic.

Do you think I should replace the fuel pump? or someone told me that it might be by ignition switch(since the car turns over right away).

It currently has the evoms gt700 package with the hitachi maf conversion. Symptoms 1. It starts right away.

2. All my lights appear before the car shuts off.

3. Sometimes when I run it hard and sometimes driving for 5 min. Very erratic!!

I have the durametric software and no codes not even right after the car shuts off!!

Any help would be much appreciated.

Jason

[2LOW4]

Caution Thread Resurection:

Any resolution to this?

My 2001 has done this twice in the last couple weeks, have had car for 2 months. First time was city driving, had drove a couple miles taking it easy to warm up. 4th gear downshifting into 3rd coming up on railroad tracks, car stalls with all the dash lights lit up. Turned key and it started right back up.

Second time fully warmed up, funny almost same place coming from opposite direction. Just cleared railroad tracks and was accerating away going through the gears, hitting about .7 bar at upshifts. Hit 5th and it just dies. Started right up with a turn of the key.

Researched here and on 6Speed, came to conclusion it was most likely plugs, coils, or both. Bought a Durametric and logged missfires for a couple days, nada, nothing not a single one. Only faults that show is clutch switch and a spoiler fault, sure they are old as clutch switch seems to work ok and the spoiler operates fine.

Since I've heard fuel mentioned multiple times think I will try and log fuel pressure or another fuel parameter with the Durametric.

It hasn't happened in over a week but am a little gun shy.

Thanks,

Steve

[2LOW4]

Playing with the Durametric today in the driveway. Letting car warm up checking out some "actual values", boom quits running.

went to ECU faults and had 1:

moduleType = MotronicDME78

DTC Count = 1

Fault Number:P1571

Description:Porsche fault code 39 - Immobilizer

Same symptom as other shut-offs. Engine just quits and all the dash lights come on.

My alarm also has the "one honk" when locking with key button. Got 4 faults in "alarm module" which will not clear, erase faults is grayed out in the alarm module menu.

9X6 Alarm Selected

About to get fault codes

moduleType = AlarmI32

DTC Count = 4

Fault Number:21

Description:W lead (DME immobilizer)

Repair Infomation:

Repair Infomation:Status: not present

Repair Infomation:Frequency counter: 1

DTC Count = 4

Fault Number:49

Description:K lead

Repair Infomation:

Repair Infomation:Status: not present

Repair Infomation:Frequency counter: 4

DTC Count = 4

Fault Number:60

Description:Central locking limit position

Repair Infomation:Lock not reached

Repair Infomation:Status: not present

Repair Infomation:Frequency counter: 1

DTC Count = 4

Fault Number:33

Description:Interior sensor faulty

Repair Infomation:

Repair Infomation:Status: not present

Repair Infomation:Frequency counter: 1

Think any of these alarm faults could be causing the immobilizer to shut the car off? Especially the W-lead and the K-lead which sound like part of the immobilizer.

Thanks,

Steve

[Loren]

P1571 Immobilizer - open circuit/no signal

Possible fault cause

- Open circuit in wiring between DME control module and alarm system

- Short circuit to ground or short circuit to B+

- Alarm system control module faulty

[2LOW4]

Thanks Loren!

Worth checking out, it seems to just stop the engine any time.

[wross996TT]

If the module was faulty it wouldn't start, so I'm guessing a short somewhere...check ground wires.

[RFM]

Turbo fuel pumps exhibit such symptoms, in some cases, when they fail. Nothing prevents you first to check the DME and pump relays anyway.

[2LOW4]

My thoughts exactly. The "K-Lead" and "W-Lead" are wires maybe?

Also, it has aftermarket non-Porsche radio. There are two amps in the floor of the trunk under the removable "floor board". Lots of wires, while they look to be connected and routed ok, it just doesn't look professional. Think I'll pop the radio/AV unit out and look at the wiring behind that. It's a Pioneer AVIC NAV unit and see how the wiring comes from the amps.

Thanks for all the help and ideas. :renntech: Fuel system next!

If the module was faulty it wouldn't start, so I'm guessing a short somewhere...check ground wires.

[911gt700]

I had RSS reflash the ecu with the evoms software and still got the shutting off issue. Had Al & Ed check the wiring for the system and everything is solid. Fuel pump next on agenda.

[Tunegoon]

Thread resurrection: Keyfob stopped remotely opening car...replaced battery. Still won't unlock doors, but car starts fine. However, sporatically (twice), once after a quick stop and another at a stop light...car goes dead. Just stops running. No warning, no error lights. Turn key over and instruments work, but won't restart. Have to take key out and wait a few seconds, then car starts up again. New immobilizer 2 years ago. Not throwing any codes at all. Scratching my head. I'm leaning towards immobilizer, but open to suggestions. Both times, full premium fuel, and problem didn't come up again for over a day. Can't find any rhyme or reason as to why. Thoughts? Thanks! 2002 996 Turbo. 41k miles. No mods.

[wross996TT]

First, start your own thread. Second get the codes read...just because nothing is showing doesn't mean codes aren't registered. Could be many things.

[Tunegoon]

first: The problem with my car is the same as the title of the thread...therefore, starting a new thread would only lead people to suggest I go to this thread.

second: the post says that there were no codes thrown...codes were read, and nothing showed up.

Anyone have any constructive help or similar experiences not covered in the thread?

[Loren]

first: The problem with my car is the same as the title of the thread...therefore, starting a new thread would only lead people to suggest I go to this thread.

second: the post says that there were no codes thrown...codes were read, and nothing showed up.

Anyone have any constructive help or similar experiences not covered in the thread?

What did you use to read the codes?

[Tunegoon]

Actron Pocket Span Plus

Hey Loren!

[Loren]

Does that show pending (engine) codes?

That reader will not show any alarm/immobilizer codes - you would need Durametric, a PST2, or PIWIS tester for that.

[phillipj]

Try using honey instead of vinegar when you want help... Just sayin... :cheers:

[Tunegoon]

Thanks Loren...good to know! Amateur mechanic here...learning a lot!

PhillipJ...I really usually do use honey and am quite grateful for renntech and Porsche enthusiasts in general for the help. Replied to the earlier post in the same manner as I received it. Probably should've taken the high road. Felt it wasn't someone trying to help, just someone not being nice. Perhaps I took it wrong, but I've looked at it a few times and it still reads like a pissy/negative post. My apologies if I'm in error. I'm just trying to save myself some money and asking for help...and do it the correct way.

You are correct...honey works better and you won't see a reaction post like that from me again.

Now, off to get the codes read with a Durametric Code reader!

Tony

[Tunegoon]

Apologies to Wross996TT. I've re-read again and maybe I read something into your post that wasn't there. Can we call it used car frustration? ;-)

[phillipj]

Tony,

No worries. Glad to have you on the forum.. :welcome: