Rainer-TR250 Posted March 22, 2008 Report Share Posted March 22, 2008 Gents, I hope somebody out there can help: I bought a TR250 and noticed that the vacuum valve (connected on one side to the vacuum retard capsule, and on the other side to inlet manifold piping system) is missing.... It seems that this valve is not available at any of the numerous parts dealerships. Now my questions: (1) Would it cause any problems if I simply blocked the vacuum lines from the retard capsule and the manifold (and if yes: what kind of problems), or (2) is anybody aware of a valve (maybe from a different vehicle) which can be used instead ? Thanks, Rainer Quote Link to post Share on other sites
Tom Fremont Posted March 22, 2008 Report Share Posted March 22, 2008 Hi Rainer. There is no need to employ the retard capsule on the distributor; it is only ever intended to function at idle. Very, very few cars still running employ this valve today as most owners haven't a clue to its purpose or benefit, which is to pull the idle down to a delightful purr and satisfy emissions regulations when idling due to the retarded timing ( minus 14 degrees approximately ). What's more, the valve is susceptible to internal swelling and dysfunction due to absorbing crankcase fume condensate which works its way back to from the inlet manifold. It will eventually dry out and resume working, but to ensure its " health " one should depress the throttle pedal slightly when switching off the engine so as to vent the residual vacuum harmlessly ( patent on this method belongs to me ). If you elect to dispense with this feature you can close off the vacuum supply line and set your static timing to 10 degrees BTDC or less, depending on fuel grade and audible pinking. When I operated this system I got the best results from using retard only - no vacuum advance. If you can find a good valve ( saw a couple on ebay NOS in the last 5 years ) you can have a real rarity in a functioning vacuum retard, and the best idling example to be had. It makes a cute sort of wriggling movement when actuated by the 1st bit of pedal action Quote Link to post Share on other sites
Rainer-TR250 Posted March 22, 2008 Author Report Share Posted March 22, 2008 (edited) Hi Tom, thousand thanks for the fast and comprehensive response ! You gave me assurance that until one of those hard-to-get-by valves crosses my way, I will try without and change timing to 10 degrees BTDC (at idle - with strobe). Thanks again - and all the Best Rainer Edited March 22, 2008 by Rainer-TR250 Quote Link to post Share on other sites
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