200 cold start problems

[Geraint Lloyd]

Ameer,

cheer for the tip. for some reason I had excluded the
CPR/WUR from my
diagnostics.
I just checked the resistance of the CPR element and
it measured at 12 ohms.
I just replaced the CPR with a 'known good' UK spec
Golf 2 GTI CPR (EV
engine) which has the same hot and cold control
pressures as the bentley
tells me i should have for the MCII. the EV CPR read
22 ohm which eems
much more like it!. the car seems to start a bit
better, although i'll
have to wait for the morning for the definitive
answer.  

the difference between the 2 CPRs is that the golf one
has no brass
aneroid chamber on the back and has no manifold
pressure hose connections.
the MCII  CPR has the manifold pressure outlet, but it
is plugged.

If i stay close to sea level(!), can anyone think of a
reason why what I
have just done is a terminally stupid idea?
I intend to run like that until I can pull the MCII
CPR apart and try to
replace the element with that of yet another EV CPR
that I have lying
around. I'm assuming that the heater elements are the
same, but does
anyone know any different?

failing that i'll try and find someone locally with a
spare 10v turbo
CPR that i could buy, beg, borrow or steal.
maybe someone who navigated me to 2nd place on the
greenhorn rally on
Wednesday  in the aforementioned EV golf and has
megasquirted his URQ?
who knows?

it looks like the mixture has never been adjusted
(hole still has OEM
metal plug) shouldn't the ECU and lambda probe sort
all of that out. I
agree that i need to check the mix at some point soon,
but if it's at
stock base setting, it can't be that far off can it?

Geraint


Ameer Antar wrote:
>
> The WUR actually could be causing your problems
since that's what
> regulates the mixture until the engine warms up. I'm
not sure how warm
> the regulator was, but 3.2 bar is pretty high if it
was cool. At least
> for the 5000 turbos, the cold control pressure
should start around
> 25psi and go up to 55psi when warm. The higher the
control pressure,
> the leaner the mixture, so it may be that the
control pressure starts
> too high for the engine to run right when cold.
>
> If you did change out the injector, you definitely
need to adjust the
> mixture a bit. Also you should check for vacuum
leaks. Good luck.
>
> -Ameer
>
>
> --------------- Original Message ---------------
> Message: 3
> Date: Sat, 15 Jul 2006 17:35:34 -0700
> From: John Larson <westcoast at mypowerpipe.com>
> Subject: Re: 200 cold start problems
> To: geraintlloyd_qc at yahoo.ca,  quattro at audifans.com
> Message-ID: <44B989D6.7040506 at mypowerpipe.com>
> Content-Type: text/plain; charset=ISO-8859-1;
format=flowed
>
> so far i have checked
>
> Injector leaks - OK
> Sys pressure 5.8 bar
> cold control pressure - 3.2 bar although it wasn't
> stone cold, but i
> dont think it's a CP issue so wasn't too careful
there
> resid pressure 3.4 bar afer 30 mins
> check valve pressure 3.2 bar after 30 mins
> i cracked open the cold start valve, and WUR
> connectors after the car
> had sat for an hour or so, i got a spray so there's
> pressure there.
> cold start valve is getting 12v whilst cranking
> the 2 black coolant temp sensors are giving the same
> reading, although
> for the price i will change these v soon.
> I lifted the flow plate with the pump on and the
> injectors spray nicely
> (they are spanking so i guess that's normal) and
shut
> off without dribbling.
>
>
> haven't checked the CSV flow rate, yet, but te car
> starts ok when cold,
> but has already started the same day
> I am about to test the WUR resistance, but am pretty
> sure that it will
> be ok.
>
> as i say, I guess that it's fuel pressure, but the
> tests seem ok
> I'm thinking
> 1 accumulator
> 2. pump check valve
> 3. temp switches (but not convinced)
> 4. stuck CSV, but the economy seems reasonable. I'll
> pull it off in
> about 10 minutes
>
> anyone got any better ideas?"
>
> Have you checked the mixture after it's warmed up? 
New injectors
> nearly always require moderate to substantial
adjustment of the
> mixture screw inside the airflow meter. This can be
done by monitoring
> the voltage at the O2 sensor while it is unplugged. 
The voltage
> should be around .5v.  With the wire attached, it
should rapidly
> fluctuate from around .2 to .8v or so. Is this a
CIS-E car?  Have you
> checked the infamous "spare" fuse in the side of the
fusebox?  It's
> NOT a spare.  I can't even recall how many of those
I've found missing
> over the years.  The cold start valve should ONLY
activate at temps
> below 30-40 degrees F, and then only for 5-10
seconds, and only while
> the starter is engaged.  John
>
>
>
>
> ------------------------------
>
>  
>

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