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mark houghton mark houghton is offline
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Join Date: Jul 2008
Location: Central Washington State
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Originally Posted by Benny771 View Post
23 degrees outside 55 humid. Car cold (overnight +) wur unplugged before test.

Valve closed 6.5 bar

Valve open 2.7 bar
Seems to me your cold control pressure is too high; without looking in my manual, I seem to think that 2.3 is the upper range of acceptability. At 2.7, you would not see adequate enrichment (remember, the higher the control pressure the less the fuel metering arm will move and the less fuel will be delivered). That could cause problems with your cold running conditions but have no impact once she's warmed up. If you know of someone that will lend you a known good WUR, then swap it out to at least put the WUR out of the equation.

Spend some time looking for vacuum leaks and/or intake air leaks. You might find something there. Unfortunately, these cars take a certain amount of trial and error before you find the culprit, since different system problems can cause similar symptoms.

Listening check: Your symptoms are hard cold starting, poor running until warmed up, and hard re-starting when warm, correct?
Mark H. 1987 930, GP White, Wevo shifter, Borla exhaust, stock everything else. The result of a massive Pelicanite good will fire recovery effort. Truely an open book, ready for the slippery slopes to modification.
Old 07-07-2011, 03:22 PM
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