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mark houghton mark houghton is offline
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Join Date: Jul 2008
Location: Central Washington State
Posts: 3,893
The "Old One" speaks great wisdom, grasshopper.

But as long as we're talking fuel pumps, consider this CIS conundrum: If fuel pressure drops, then the air flow metering arm will deflect more, relatively speaking. That's pretty much what the WUR does by dropping the pressure ("control" pressure). So if you lose pressure, wouldn't you see a rich condition because the arm deflects more and allows more fuel to flow? Ahhhh....grasshopper....what's really happening when one loses a pump? Do we lose pressure, or is pressure sustained with only one pump running and all we lose is fuel volume to the injectors...thus, leaning as you've experienced?

Just an open ended question, as our 930's will run OK - to a point - with only one pump, but I wouldn't trust it on boost.

Wax on, wax off....
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.

Last edited by mark houghton; 10-11-2010 at 08:21 PM..
Old 10-11-2010, 08:13 PM
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