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Re: '89 200TQ: control pressure regulator help needed

In a message dated 96-12-16 19:06:14 EST, you write:

> The Control Pressure Regulator is a very low tech piece of equipment.  It 
>  consists of a pressure regulating diaphragm valve that has a heated
>  lic strip which controls the outlet pressure.  On your 200Q you should
>  have some vacuum (actually boost) lines connected to modulate the control 
>  pressure as manifold goes above atmospheric.

No, it does not have, although Bentley shows them.

Steve, thank you very much for a quick response. I do have some additional

>  If you have a Bentley it will include a copy of the graph showing control 
>  pressure given a cold engine and measured over ambient temperature.
>  this graph shows an acceptable pressure range that increases with 
> temperature.

It does it only from +20 to +70C. Bentley does not go into negative
The trouble is, my car has problem keeping the warm-up idle at negative
I have checked the pressure in accordance to Bentley.
SOB meets the spec, although consistently on it's highest margine:

Fuel pressure (valve on the gage is open, gasoline flows through the gage):
at +20C = 23psi (1.6 bar)
at +50C = 51psi (3.4 bar)

System pressure (valve is closed):
at +50C = 95psi (6.6bar)

So, the control pressure regulator senses the temperature by it's own body (a
bi-metal strip) and not with a separate dedicated temperature sensor? It
seems to me that somebody posted a similar problem, that turned out to be a
poor connection between a temperature sensor and it's plug.

>  I had occasion to disassemble one of these and found that there is a slug 
>  in the side of the casting that adjusts the bias on the bimetallic strip.
> You
>  can adjust the mixture by varying the control pressure by playing with
>  slug ... but be careful ... as you can imagine it is difficult to back the

>  slug out once it is pounded in!  You may end up needing to take apart the 
> CPR.

I'd like to take it apart to see what's inside. Can I reuse the whatever
gaskets I'll be taking apart or do I need to get them beforehand?


Igor Kessel