Warm Up regulator for 964 Porsche 911 Turbo, 1991
Discussion
Can anyone help me. I've just purchased a 911 turbo, (964 year 1991). I've taken to have the 1 bar boost spring and the garage reported a warmup regulator broken. This part is £670 + VAT!!!
Not only that the warm-up valve we are being told has a big hole in the side and is leaking fuel!!
Does anybody know what is going on here???
Not only that the warm-up valve we are being told has a big hole in the side and is leaking fuel!!
Does anybody know what is going on here???
911Dan said:
Not only that the warm-up valve we are being told has a big hole in the side and is leaking fuel!!
Does anybody know what is going on here???
Errr, you may need a new warm-up valve????
I am not sure how they work, but if that's what the man says... if you don't believe him, get it booked in elsewhere and see if they concur.
You may be able to get the part cheaper at a dismantlers/breakers or as a factor part through Eurocarparts.com (perhaps).
Otherwise you'll have to bite the bullet. The Turbos are normally a bit more expensive to run; comes with thye territory (and performance) I'm afraid.
please tell me what a "warm up regulator valve" is please? 
Well you did ask...
Control pressure (or counter pressure) is the pressure that is metered to the top of the fuel plunger on a K-Jet system. By changing the counter pressure, the resistance to plunger movement is changed, allowing enrichment and enleanment of the fuel mixture to the engine. On a car equipped with K-Jet, this pressure is controlled by the warm-up regulator.
The warm-up regulator only compensates for engine temperature and is therefore a rather coarse control of fuel mixture. (Some K-Jet warm-up regulators also have a vacuum port to help with the acceleration enrichment and deceleration enleanment function.) Typical control pressures on a K-Jet warm-up regulator are 55 psi with the engine at full operating temperature and 20 to 30 psi on a cold engine. (The colder the engine, the lower the pressure.)
A car equipped with K-Jet Lambda also changes control pressure with a warm-up regulator (with pressures similar to a plain K-Jet system), but also controls lower chamber pressure in the fuel distributor by bleeding pressure through a frequency valve. By modifying lower chamber pressure, a change in volume of injected fuel is made, enriching or enleaning the mixture. The frequency valve is nothing more than an electrically duty-cycled fuel pressure regulator controlled by an on-board computer in response to an oxygen sensor signal. This system provides a more precise and rapid control of fuel mixture. Typical duty cycle on a properly running engine is 45 percent to 55 percent duty and fluctuating. A quick test of this system is to start the engine and test the frequency valve for vibration or noise -- it should vibrate. Also, unplugging the oxygen sensor will put the system in open loop and fix the frequency valve at a 50 percent duty cycle.
Dontcha just love google?
Basically isn't a warm-up regulator an additional injector, or another similar means of enriching the mixture, that operates when temperature sensors say the engine is cold? The K-Jetronic system is probably more complicated as Dom's googling also mentions leaning off the mixture as well. Like most tech stuff it's 100% accurate but was probably generated by translating from German via Japanese, using the same cunninglinguist that does flat-pack assembly instructions.
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