[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re:(long)audi 5000 Turbo warm up regulator?



>From: "Winggee" <winggee@hotmail.com>
>
>how much does a audi 5k warmup regulator usually run for? used, new, etc?

New, the dealership would prolly tear you a new one. Used, in the junkyard 
it sells as a "doohickey" for about $5.

>and what does it exactly do? does it use the cold start valve as an extra 
>injector? how does this compare with a stock one off one of our cars?

No, it does not use the cold start valve. That was not designed for this 
purpose. The "Load sensing" control pressure regulator (found also on Audi 
Coupe GT's and 5000 turbo's, etc.) has a vacuum port to the intake manifold. 
When there is boost (or low vacuum), the CPR causes the mixture to be 
enriched.

If that satisfies the "how" part for you, then yer done. Enqiring minds read 
on, but be forewarned that it gets somewhat hairy here on out. I'll do my 
best to keep it simple. This is all for CIS, not CIS-E BTW.

The CPR (AKA, warm up regulator) regulates the (you guessed it) control 
pressure. So WTF is control pressure? Well, it's sorta like this. Control 
pressure is the fuel pressure that is "on top" of the plunger. System 
pressure is on the bottom, and as the airflow plate pushes up the plunger, 
the system pressure flows to the injectors. Now, the Control pressure is 
pushing against the plunger, resisting it's upward movement. Here's the 
basic idea--- decrease the control pressure, and the plunger is allowed to 
travel further up and more fuel gets delivered to the injectors. This is how 
it enriches the mixture.

So what does the CPR do? It basically bleeds off fuel from the control 
pressure side, and returns it to the tank. That's what the 2 lines are, one 
if from control pressure, and the other goes to the fuel return line. Inside 
the CPR is a diaphragm that does the "bleeding" and connected to the 
diaphragm is a bimetallic strip. The bimatallic strip is wrapped with wire 
from a heating element connected to +12V when the ignition is -On-. This is 
what the electric plug is for.

So, when the car is cold, the diaphragm is open, and fuel is bled off. 
(yummy cold start enrichment). After 2-3minutes the bimetallic strip has 
been heated enough to close the diaphragm and shut off the bleeding. Unless 
you live in Alaska or something, and it's -20F outside, in which case the 
motor is _very_ cold. Then (because the CPR is bolted to the block) the 
enrichment will last until the motor is mostly warm. If you live in 
reasonable climates the CPR can be relocated anywhere you want, and the car 
will drive just fine.

Lastly, the Audi one (there are different ones, you want the one with the 
vacuum ports on the side, not just the top) basically just has a vacuum 
chamber connected to the diaphragm, so that at positive manifold pressure, 
the CPR bleeds off some fuel and enriches the mixture. A good idea on a 
Turbo car, questionable if any improvements for a N/A car.

Whew, that was longer than I planned. But now you know, and knowing is half 
the battle!!


Jonas
85 Scirocco 2.0
78 Scirocco 1.8
For direct reply: jonas@metabolex.com
http://www.geocities.com/scirocco2l8v

_________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.

Share information about yourself, create your own public profile at 
http://profiles.msn.com.


--
Email problems to: scirocco-l-probs@scirocco.org  To unsubscibe send
"unsubscribe scirocco-l" in the message to majordomo@scirocco.org