Thermo Switch Location -- 88 5KSQ

[Huw Powell]

On 2/8/2011 11:05 AM, Tony Hoffman wrote:
> The NF engine is not covered in teh 5000 manual, IIRC. it will be
> covered in the 100/200 manual. Only the later '88 5000's got that
> engine, and I don't believe that's how it was originally planned.

87s got it, too.

> Nonetheless, it uses the same setup as the turbo cars, and the 2.0 FWD
> 80/90's. We always called this system the CIS-motronic system.

No, it is CIS-E3.

> That is, the ECU controls the firing of the cold start injector. I'd
> start by checking for power and ground at the cold start injector while
> cranking. The power side usually comes from the Starter, while the
> ground that used to come from the thermo-time switch now will come from
> your ECU.

I should look this up in my 90Q Bentley...

But anyway, it was a "very cold" start problem IIRC, and I'd suspect 
fuel pressure leakdown (via injectors or more likely check valve), and 
you just can't get enough fuel into the cylinders.  I think on my black 
90Q with similar issues (very hard start when 15 dF after -15 dF nights) 
I used to try "turn on the ignition, let pump run for that few seconds 
that it usually does" x about 5 in case that would build up a bit of 
pressure.  Can't really remember if it worked or not, it was a few 
winters back.

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/