John Speake

Certainly having a model to use would make the task of making up a new one much easier. You will be able to source all the 2 and 3 pin connectors from Roger. But you will have to reuse the two 25 way connectors.

M. Requin

I think this discussion has really gone in a productive direction, and I hope that if you do try a rebuild you will document it here.

gronkX

If I do a rebuild, I'll make sure to document everything. Anyone got a donor they can spare?

But I don't know how productive it is (for me) - car is still sitting in the garage not running

gronkX

Update:

I was looking for details on what was involved in taking out the wiring harness, and ran across one thread about how many of the "intermittent starting" problems were related to the CPS, and that wiring the connectors together directly (rather than leave the female end in the bracket) might help.

So I tried that, and lo and behold: the car started right up.

M. Requin

Thanks for the followup!

worf928

That's good news. When I posted, the other day, about the injectors, when I was done I remembered your 'no spark' observation.

You do realize that moving the CPS branch of the harness around and suddenly having the car start is another sign that your existing engine harness is near-end-of-life? You've likely got a break in one of the two (non-shield) wires and moving the harness around gets better (or worse) contact.

One way to check is to wrap a bit of safety wire around the CPS harness branch (or coat hanger, I guess) that's long enough so that you can wiggle the harness when the engine is running. If you can wiggle the harness with the wire and the car dies, then you know, for sure, that you've got a harness issue. If the CPS is pretty new then you know it's on the engine side not the sender side.


Maybe it is coincidence, or may it's something specific to the S3s, but about 7 years ago I dealt with these exact same symptoms on a customer S3 car. Long story short, after two repairs to the CPS branch of the harness that worked for a while, I discovered a third intermittent break in the leads deep in the harness. A good used harness from Pelican (? probably, can't remember) was the final solution.

From then on my rule of thumb has been: one harness repair is fine. another one just like the first is a sign of trouble. three means it's time to stop wasting time and money and replace the harness.

Good luck.

gronkX

So I ordered a used wiring harness, but it was in no better condition than the existing one.

Instead, my mechanic replaced all of the FI connectors, and checked & repaired the CPS connector. Again, the car started & ran for a few days, then died again.

Other than putting it up on bringatrailer (which at this point I'm seriously considering) is there anything else I've missed?

I guess the next step will be to ship the computers off to get checked & rebuilt. Or hoping prices for aluminum go up

Kiln_Red

What is the behavior of the tachometer during cranking when the result is a no-start?

SMTCapeCod

Is it fixed, or sold?

hwyengr

I'm pretty sure this is the Vanster BaT car.