1996 Chevy Lumina random missfire codes/poor mileage

1996 CHEVROLET LUMINA
143,000 MILES • 6 CYL • FWD • AUTOMATIC
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RBLUMENTHAL
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I suspect a fuel issue, but after testing pressure, the regulator, filter and pump, I am at a loss. The car send random missfire codes on several different cylinders. The pump, regulator and filter (just replaced) all check out as normal. The engine cuts out at higher RPMs with no load, and then fires back up, then cuts out over and over again. it will also start loping at various times and then run smooth again. The code pops up, then the engine runs fine and the code disappears. I am at a loss. Checked vacuum lines, repaired one, and now I am not sure what to check. Mileage has dropped from 27 to 16 over the last 6 months. No smoke from the tailpipe. Ideas?
Jul 4, 2009 at 12:40 PM
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BUDDYCRAIGG
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for you to have lost MPG, it's not a problem of fuel not getting to the engine.

it's either getting too much fuel and the sparkplugs cant ignite the mixture from leaking injectors,

or the spark is weak, or not there at all, from failing coils or ignition control module.
Jul 4, 2009 at 6:29 PM