Struts replaced ... now won't start? [4kq]

[SJ]

Two things come to mind with "cold start then dies" symptoms:

One: you have an air leak.
The car starts because the "choke" injector gives it extra gas. But this
injector cuts out after a few seconds, leaving you with a lean mixture and
the engine dies.
When I had this same problem, I found the rubber boot leading from the air
flow sensor/fuel regulator assy to the intake manifold had cracks in it  . .
. in the bellows area. Silicone rubber cement fixed that temporarily until I
got a replacement from a junkyard.
Or, you may have air leaks someplace else. Like an ISV valve stuck in open
position, or disconnected/broken/cracked vacuum lines.

Two: A sensor is telling your ECU that the engine is warm.
The engiine starts up with extra juice from "choke" injector, but then dies
because the ECU is being provided with wrong info from defective temp
sensor, which is telling the ECU that the engine is warm . . .so the ECU
leans out the mixture and the engine stalls.

I think on a cold engine, the sensor should read zero. The Bentley gives you
instructions for bypassing this sensor . . I think its a short for cold
engine and 14k ohms for warm engine . . . . .but dont quote me on this.
I think on the earlier cars this sensor was called the thermoswitch, which
the ECU used for open loop operation before the Oxygen Sensor kicked
in(closed loop).

Hope that helps with your troubleshooting.

SJ
85 4k - - sold but still on the road
88 5kq
90 100q

> Message: 12
> Date: Mon, 4 Nov 2002 07:27:58 -0800 (PST)
> From: "Bob H." <rjh_tsi at yahoo.com>
> Reply-To: bob at hodgeman.org
> Subject: Struts replaced ... now won't start?  [4kq]
> To: quattro at audifans.com
>
> The car's been up on jack stands for about a month and a half while I
> found the time to replace the strut cartridges (thanks to everyone who's
> helped with that effort).
>
> Now, after charging the dead battery, the car won't start.  Well,
> actually, it starts, runs for a second or two, then just dies.  If I give
> it any gas during the few seconds that it is running ... it dies
> immediately.
>
> I've charged the battery three times now, and I get about 10 good cranks
> per charge.  And, it still hasn't started.  I didn't touch anything under
> the hood, except that I had disconnected the negative battery terminal.
> That looks to be making good contact, though.
>
> Ideas?
>
> -Bob
>  '86 4kq beater