I think I fixed it! (wasn't the DME)

[MonkeyBoy]

Some of you may recall a problem I was having with my engine cutting out at random. Two weeks ago it started doing this every time I drove and I played with it a bit and think I may have fixed it. First thing I did was check the harness to the mass airflow sensor to see if the update had been done - and it had - but I noticed that the connector came off without requiring me to push on the metal spring lock. Also, there was a hose back there that was up against the connector and not in it's holder.

At the same time I noticed that one of my other Bosch connectors didn't have a metal spring clamp on it. I apologize for my mechanical ignorance, but it was the one connecting to one of the "clusters" of spark plugs. I pulled out the connector and noticed that the middle of the three female connections was spread apart too much to make decent contact. I squished the connectors together to make better contact and reattached it.

Not sure what I did exactly, but my car has been working great for the last two weeks.

[Ted Stringer]

looks like you headed off a huge repair bill.

------------------
Ted Stringer
nuke3@juno.com
'84 911 Targa aka pocketrocket

[91C2wrencher]

MAF update? what year is your car? does this update apply to the 964?
thanks

[MonkeyBoy]

My car is a 90 C4. I received the following info from Tom Sharpes on the 964 smartgroup:

Air Flow Meter Cover Causing Erratic Idle, Loss of Power Technical Service Bulletin

In part, this is what is says:

Possible Cause: The air flow meter wiring harness protective cover contacts the engine ventilation hoses causing current flow interruptions on the plug terminals.

Vehicle Information: The protective cover on the air flow meter wiring harness plug was discontinued from production date February 13, 1990. VIN's 96 - LS 45 1659 Coupe 96 - LS 46 0409 Targa 96 - LS 47 1072 Cabriolet

Repair Information: 911 Carrera 2 model year 1990 and 911 Carrera 4 model years 1989 and 1990 prior to the above VIN's should be modified when the engine is removed or when working on the air flow meter, even if no engine performance problems are present.

The bottom line is to first look at your air flow meter housing (next to the air filter box on the left), if the fix was completed they should have put a black dot on the housing. Key word here is SHOULD. I checked mine and it did not have it, so I became concerned because they recommend that the engine be out of the car to do the repair ! YIKES.

I got my trusty digital camera and squeezed it through the small places near the airbox just enough to get some great clear pix of the connector they are referring talking about. Mine had the repair done. I don’t know how to post pix to this site, so if your interested I can email them.

They recommend this connector be fixed even if you are not experiencing any problems because it will sooner or later.

The problem is the wires get pulled by an interference with a couple of hoses causing the wires to pull out to the connector just enough to break contact intermittently and causing all of the problems. But when they make full contact again the problem goes away (usually about the same millisecond you pull into the Porsche service bay!)


[This message has been edited by MonkeyBoy (edited 08-20-2001).]

[MonkeyBoy]

Just want to report that I'm fully convinced that this problem is fixed! It's been several months now and the car runs like a top. Original problem was detailed on the thread:
http://www.pelicanparts.com/ultimate/Forum3/HTML/009545.html

Thanks again for everyone's help. I recently learned that this intermittant problem was the reason that the PO sold the car... and why he sold it to me so cheap!