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mark houghton mark houghton is offline
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Join Date: Jul 2008
Location: Central Washington State
Posts: 3,861
If you had a serious vacuum leak I would think your idle AFR would show it as well, but maybe not. Try squirting starter fluid or brake cleaner around all the intake injector blocks. Perhaps your wrench over-torqued them and cracked a couple to where they're sucking air.

Couple other thoughts: I wonder if the metering arm is moving freely. Almost sounds like it's not, since you go instantly lean when pressing on the gas. If the arm doesn't pull down in response to air flow then you wouldn't be getting the fuel needed. Don't know why this would be affected by a top end rebuild, though, but you never know. Pull off the air cleaner and push down on the metering plate to see if it moves freely. And/or, start the car up and push down on the mixture adjusting screw to where it contacts the metering arm and push further to see if your car will stumble from being overly rich.

One other thought: There is a frequency valve back behind the fuel distributor that's part of the Lambda system. If perchance your wrench had unplugged the wiring to it, you will see a very lean condition that cannot be corrected with any amount of adjustment. Do a listening check: Turn the key but don't start the engine. Force the pumps to run by pulling the green connector behind and on the left side of the fuel head (it connects to the metering arm via a micro switch). Pulling the plug will make the pumps come on as well as the frequency valve. You should be able to hear the valve's obnoxious buzzing. And while doing this test, go up front and pull each fuel pump relay one at a time and listen for the affected pump to stop running....just to confirm that both pumps are operating.

That's a start, anyway. More help to come I'm sure.
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 04-06-2013, 05:53 AM
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