King James

As many of you know (from a few of my previous posts), I've got an 82 Weissach 5sp that has been OOC (out of commission) for going on 2 years following a TB/WP change...Current state is this:

-Starts right up but will not stay running w/out accelerator floored. This creates a condition where (with pedal floored) the AFM flap bangs a few times, engine barely chugs along, then suddenly roars to life and runs fairly well between 2000-3000 RPMs. I am unable to keep it steady in that range, having to keep pumping pedal to keep reving...if I let off the pedal, she dies.

I've checked EVERYTHING I can think of and everything checks out...which brings me to this:
I have checked the Rennlist archives and keep coming up on the infamous 'Green Wire' as a potential culprit. Including the old thread in which Jim Bailey states that basically, the symptoms I am experiencing (acting like a vacum leak, etc.) can be the result of a faulty Green Wire.
I've had my 928 for 5+years and have never changed it, the PO kept meticulous records but doesn't detail anywhere that he changed it, yet it looks bright green and by way of visual inspection looks fairly new....

At >$100 a pop, I'd rather determine whether or not this is the issue vs. just starting to throw money at 'maybe it's this, maybe it's that'...

Is there a way to definitively test the 'Green Wire' to tell if it's working correctly?

I would love to get this bad boy back on the road instead of locking it up for another Wisconsin Winter and trying to remember what all I've tried to do to it next Spring...that's unbearable to even think about!

Help...

hacker-pschorr

IMO after 25 years it's time to replace it. I ordered a replacement green wire for both of my 928's, just haven't installed them yet.

a4sfed928

I think you would have to have an oscilloscope to look at the voltage wave form to be 100% sure. Do you have a timing light or o-scope?

dr bob

You can check basic integrity with an ohm meter, but the wire itself is pretty toasty if it's the original. The green wire is likely not the source of your woes, however. The 'starts right up' statement might steer me away, but a new one as a PM item would be very reasonable. Enzo (Erik) is in your neighborhood (GB) so a little road trip and experiment might be in order if you really don't want to invest in a new wire to test. The drive up and back twice will cost about the same as a new green wire delivered, though.

hacker-pschorr

Wow, did not see Milwauke in his sig.

There are a few very knowledgeable 928'ers in the milwaukee area.

I agree it does not sound like a green wire issue. Just saying I would replace one that old on a perfectly running car.

King James

Ok, So it doesn't sound like a green wire issue (although consensus indicates it would be wise as a PM item)
Thoughts on what it might be or...Enzo (Erik) mentions 'very knowledgable' 928 guys in the area? Man, I would love to get a 2nd opinion on what is happening here, any Milwaukee area Rennlisters got their ears on and wouldn't mind giving me their 2¢ ?

Thanks for the replies, as always I appreciate it!

KJ

Chuck Schreiber

Change it out. It will probably last another 20 some odd years!
My 79 only has 64K on the clock and my Green wire was toast!! Bare in at least 3 spots and the connectors fell apart when I disconnected them.

Jean-Louis

Where are you located in Milwaukee?
I am in waukesha

SwayBar

Sounds like to me the cam timing is off.

Garth S

+1 .... at least on one cam, which is why it starts - but runs like crap: also, check the static timing, and confirm that the advance comes in smoothly and completely by ~3000 rpm ( with vac lines off).

King James

Hi Jean-Louis!

I'm right down the road in Wauwatosa...

Jean-Louis

OK let's try to get together

Bernie

+2 on the cam timing.
Since it hasn't run right after you did the timing belt!
Is it possible that one or both cams may not have been perfectly aligned when you installed the new belt?

Cheers
Bernie

Jean-Louis

KJ who did the TB job on you r car?

SMTCapeCod

Cam timing, seriously? I'm thinking clog in fuel delivery. Jean Lousie is a great resource, you are fortunate to have him nearby -- and he's fortunate to get his mits on a weissach!