swmic

Rick,

Great news and thanks for posting your solution! These cars can really test your patience. Let's hope Rob found his problem.

Cupcar#12

No Love again for me - infact acter the inital ride it got much worse.

back to the drawing board - (and off to the shop next week as i formally give up and am letting them trace it down and fix it.)

i'll look at the Hal sensor tonight and rewire the connector to the ACU again but am not expecting much right now.

Smokin

Rob.... Sorry to hear that. Thanks for your help with mine. I still can't believe the difference. Jason burned me a chip a long time ago. It helped greatly but it would still stall out and have the "hiccups" every now and then. NOW I see the true value of Jason's chip! It worked like a charm! Having the LWF used to make my 911 stall out. I spent some time over the past two days TRYING to make it stall... It wouldn't! It sure is nice being able to stop at a light or intersection and not have to worry about watching the rpms to make sure it didn't stall. Even then... With the AC on... I'd still stall out at times when I was in traffic.

Thanks for the help. I appreciate it greatly! I hope you get yours sorted soon... And with as little expense as possible!

Smokin

Rob,
What did you ever find out on this? My Hall Sensor code is back as well as the cutout upon acceleration. Sometimes it dies... Sometimes not... It may run fine and then, all of a sudden, it idles fine but dies when I hit the accelerator.

I was playing around with the Hall Sensor connection this weekend after it started dying on me again. The code is back and the sensor connector is loose. (The part on the distributor)

Just wondering what you found....

Cupcar#12

mine was weird... it left both adrian, my mechanic and me scratching our heads.
The wiring loom to the ACU was shorting out against the grounded ACU box - to fix it i remounted the ACU box (insulated) and rewrapped the loom (no wires were cut or appeared to be exposed.

the problem went away and has not reoccured.

durring the course of my investigations i bought 2 extra ACU's - i could send you one to try and see if that fixes your issue.
Have you tried bypassing the ACU DME cut off circuit yet? that would eliminate it as the cause.

Smokin

Rob,

I still haven't had a chance to get to it yet. We had friends from out of town come in this past weekend and I couldn't get to it. I'm shooting for tomorrow or Wednesday. I'll keep you posted...

bmohr

same issue of engine cut out during highway drives. I haven't updated my MAF sensor yet..it does touch other components so I figure that is the culprit, but honestly the car doesn't cut out due to bumps. It's just a random cut out. Actually, it seems to happen when I've had a slight engine overfill condition. Not sure if there is anything related there. I'm going to do the TSP to the MAF, then look at the O2 sensor and report back.

PCar SBA

Keep in mind that the entire drive train moves ever so sligtly every time torque changes. This movement is enough to influence the connector to the MAF. So the cut-out can be very random and still it is caused by the MAF even if you are not going over a bump.

Another known culprit is the O2 sensor connector. It too can make the car stall. Try re-seating both connectors and see if it makes a difference.

bmohr

Will do, thanks for the advice and reply. I have to tackle this and sort out an exhaust smell coming into my cabin as well this weekend. Argh. I'll post my results.

KirkF

I took my 964 for a drive on Sunday and also noticed it randomly cutting out for brief periods.
Looks like I have a long list of possible culprits to investigate...


Sigh

Kirk

gchristofi

May or may not be relevant, but I recently 'invested' in an bmw e30 325 as a track car. These do seem to share much of the same heritage as our 964s and use motronic DMEs as well. It is fairly common for these to gradually fail due to dry solder joints that cause intermittent cut outs.

On the faulty DMEs I've come across so far, I could usually reproduce the problem by tapping the case whilst the engine was running.

Just a thought......

sml

My car had random cut-outs whilst driving.

Dropped off my DME unit to local TV repair guy, all solder joints on the circuit boards were resoldered for $30, installed and problem solved.

Out of the many many solder joints, he said he saw a few dodgy looking solder joints near the big black wiring harness connection socket thing.

gchristofi

Yes, that ties in with my experience too, although since I can get the bmw DMEs for about $15 I have been using my own soldering 'skills' to mixed results

Last few 964 DMEs I have seen for sale were £400 +. Talk about Porsche tax!

kenloen

as you got nothing to loose..

take the clock out of the dashboard, strip the pcb's apart and resolder everything in there. Beware there are 3 poles soldered in that connect the inner pcb to the outer pcb, use solder mop to disconnect before pulling apart.

cured my longstanding electrical issues. everything from being unable to open the doors in the morning (from total electrical cutout), being unable to disable the alarm and start, xmas tree effect, sometimes just the tiptronic would go into safe mode, misfire, stereo cutting out - and issues hitting potholes.

I replaced all sorts of components (some necessary) and it was this finally resolved.

good luck!

bmohr

hmm, i'll keep that in mind. For now, its' the MAF tsp fix, o2 sensor and connection checks. Then i'll move onto the DME and clock solder points. Seems like these are all worthwhile pre emptive repairs regardless of the final "fix". Many thanks for the inputs.