If and when the problem returns in addition to reading codes I will check for spark.


I hope so.... although did the very scientific wiggle of the loose hall sensor union whilst running the engine and couldn't reproduce the fault.

Guess I'll just get a really good breakdown/recovery policy for the trip to the Continent

 

I strongly suggest following through on the TSB AB-Oz linked to earlier in the post (if you haven't already) — because I didn't do 100% of the documented procedure (I re-seated the AFM wiring but didn't ziptie its connector as shown), it took $100 wasted with the shop to re-identify and re-apply the already "applied" solution! My rough-running '89 was going through seemingly identical problems as yours until this fix stopped the issue cold.

 

It sounds like the problem I had last weekend in Brussels...

My car would loose power on occasion, especially after going over a bump. It got to the stage where I pulled over and got the car recovered to the Porsche dealer who managed to trace it to a loose connection on the sensor at the rear of the air flow sensor next to the air intake (silver box).

They took the connector off and compressed the fittings again (need doing periodically) and the car never missed a beat in the 300 miles I drove home. Cost 160 euro's to fix, which was a great relief.

I would get that sensor off and tighten it or use cable ties to compress it on to the fixings...

Hope this helps.

 

I have the same issues as you guys - but I cant solve my problem. It idles ok, it drives ok, but when I put my foot down whilst driving at 40mph - it goes flat and wants to cut out - when I release the peddle it continues to drive OK. Is this fuel related or electrical ?
i replaced the DME relay, fuel fliter and cleaned the rotors and dist cap ?

Please help !

where do I connect the scantool device on a 1990 911 ?

 

aussiehussey —i'm strongly convinced you're seeing that same AFM cable connection issue mentioned above in the thread and covered by the TSB. Go follow those instructions, especially the KEY part about zip-tying the connector, and see if the problem magically goes away. That's exactly what happened for me.

 

Same problem here but it ONLY happens at track days! I have the Autothority Mass air sensor so I guess I'll just check the connections and make sure the wire insulation is not near other hoses(?!)

white rsa

 

Check your battery ground strap, I recently had a misfire and a charging problem, replaced the ground cable and cleaned all contact points, all problems gone.
Hall sensor in distributor will be for the sequential injection, if disconnected ecu will just go into batch mode.

 

Thanks for your insight. It appears my problem is the transmission control module. Does anyone know where I can buy one from and does this sound familiar ?
where is the control module located ?

any help is much appreciated - new to 911's

 

i'm following this thread with interest because we have the same problem with my friends car and we haven't found the problem yet. So I bump this question from above.
- What is the transmission control module? What does it do and where is it located?! I never heard of this part before on a C2.

 

Just a shot in the dark. My Dad had a similar problem with his '92. We checked almost everything. Just for the heck of it we put a timing light on both sets of wires and found the distributor belt had been slipping and eventually broke. This was causing the same symptoms. Have you looked at this?

 

Yes we have, and it's OK.

 

AHA!

Sorry to hijack your post, but....

I've had a continuing problem with an eratic dead miss lasting anywhere from what feels like one plug failing to fire to a couple of dead rpm's (throws you out of your seat back). Car runs excellent otherwise, very smooth and strong. Problem is intermittent, may go for an entire commute with no problem, then miss a half dozen times on the next short trip. My hall sensor connector had become loose and I wire tied it to the dist, but I've been wondering if it was the problem. Based on this info, maybe I should just go ahead and replace it to make sure.

Other symptom was that my stereo system would lose memory settings, indicating a loss of power. Also, it seemed to happen more frequently when resuming speed after lifting off / deceleration. The problem has continued through an engine rebuild, so I feel like it is "ancilliary related" parts (see below).

I have replaced inition system from coils through rotars and plugs (which fixed a multitude of problems), recent fuel pump, recent oxygen sensor, three new fuel relays, cleaned ISV, cleaned MAF, and made modification to connector on MAF.

I had narrowed down to:

fault in battery or cables (big stereo system amp?????)
ISV malfunction
throttle cable adjustment = ISV malfunction
injector(s) malfunctioning

Any suggestions - ANYONE????

 

Have you checked the grounds? I've read where replacing the main ground cable from the battery to the chassis made a difference even though it seemed to be okay. Loosing battery settings sure sounds like a power interruption problem.

 

Aftermarket chip? Are they staying plugged in? Idea from my mechanic. Claims he solved same problems by re-seating the chip.

white rsa

 

doesn't anyone know what the "transmission control modul" mentioned above is?