CIS Guru - Advice Need (strange problem)

[sukchew at cox-internet.com (Chuck Blue)]

The first thing I would check would be the Aux.air regulator.You might want 
to test the control pressure regulator.It is supposed to only operate during 
warm up but check it anyway.
ole blue
----- Original Message ----- 
From: "Cory Langford" <Cory_Langford@bcit.ca>
To: "Scirocco List" <scirocco-l@scirocco.org>
Sent: Monday, February 13, 2006 10:18 AM
Subject: CIS Guru - Advice Need (strange problem)


> This is a little long, but if you know CIS please read....
>
>
>
> Just when I think I have everything worked out again, the mk1 has to be a
> vw and get an attitude :)
>
> I need some suggestions from those old skool CIS gurus out there...
>
> Here is the scoop:
>
> Straight CIS with the following changes:   Turbo'd so fuel added via Audi
> 5K press reg.  Replaced the bosch Coil with a Blaster 3.  That is it.  It
> is still straight cis.
>
> Problem:  Car runs fine when first started.  When engine (and engine bay)
> is coolish car runs GREAT.  Nice power, great torque, etc.
>
> When the car starts to warm up (oil temp at about 90 deg. cel.  water temp
> about 1/2 way) car starts to idle high (this morning 2K).
>
> When the car gets to operating temp for a little while (couple minutes
> into 100 deg cel. oil temp and water temp just over 1/2 way on the gauge)
> idle drops to about 1200.
>
> When the water temp rises a bit (and engine bay temp) - oil temp stays at
> 100, water about 3/4 (ie: when driving in traffic) car starts to bog at
> 2-2500 again and idle rolls significantly (1000-300 roll).
>
>
> Here is what I have done (I thought it was a fuel delivery problem at
> first because it started to lean out when warm).
>
> Replaced the fuel pump (it was just starting to buzz, nothing bad but
> figured why not)
> Replaced the Pressure reg with a Volvo turbo on I had on the shelf
> Replaced all 4 injectors
> Replaced the fuel pump check valve
> Replaced the fuel filter.
>
> Problem persisted, so replaced the Volvo fuel press reg with one I snagged
> from a good working CIS turbo engine just in case it was an issue.
>
> Problem persists.
>
> This weekend I was going to start looking at electrical (as I think I have
> exhausted the fuel area).  But time did not permit any work on the car.
>
> I thought I would start with a new coil maybe?  Plug wires?  I can't see
> them being an issue. Blaster 3 coil is only about 2 years old, and the
> wires were replaced at the same time with a new bosch set.  The cap, rotor
> and plugs are about 2 months old.
>
>
>
> Here is the strange thing I noticed this morning on the way into work:
>
> It did its usual idle rolling, etc.  BUT This morning the free way was
> uncommonly light on traffic so I decided to wind it up.  I gave it a real
> good run.  Oil temp rose slightly (as it does when the turbo heats) to
> about 110 deg. cel.  Water temp dropped drastically, nice cold wind into
> the rad at high speeds.
>
> What I noticed was as soon as the water temp went down to about 1/3-1/4
> the car kicked back into the "good" mode.  Idle smoothed out, power
> restored at 2K, etc.  Oil temp was still up, but engine bay temp was way
> down.
>
>
> Now from personal experience, rolling idle when everything else has been
> checked (timing, mixture, base idle, etc) usually means a vac. leak in a
> CIS car.
>
> So now I am starting to think I should be looking for a vac leak that
> presents itself when the engine bay heats up, and seals itself when the
> bay cools.  A great thing to search for :)
>
>
>
> Any Ideas?  I am running low on things to change...
>
>
> Cory Langford
> '86 Roc turbo,
> '78 Roc turbo - Daily driver project,
> '65 Ghia Coupe
> 95 Eurovan, etc, etc... :)
>
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