1990 Lumina no start

1990 CHEVROLET LUMINA
223,000 MILES • 6 CYL • FWD • AUTOMATIC
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GOLFNGUITARS
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1990 Lumina 3.1 wont start. It was hesitating or stumbling for a few days, and finally stalled out one day while driving. Started right up the next day and stalled out when fully warmed up. Now it won't start at all. I have fuel pressure, I have spark, I don't seem to have fuel at the injectors. I removed a spark plug while someone cranked the engine, no fuel odor, plugs were dry. I replaced the Ignition module and coil packs, no difference. I replaced the ECM, no difference. The crankshaft sensor was changed 4 years ago.
Assuming the crankshaft sensor is operating correctly, what would cause the injectors to not fire? Unfortunately, the injectors on this engine are under the plenum. So it would take some time to get at them. I am stumped. Many other sensors have been recently changed. MAP, ECT, TPS, IAT, plugs and wires. It ran great before this.
May 5, 2011 at 2:45 AM
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RASMATAZ
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determine if its a fuel or spark problem
May 5, 2011 at 6:04 AM
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GOLFNGUITARS
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I have correct fuel pressure at the schrader valve. I removed one plug, I have strong spark. I will test other plugs for spark this afternoon. The injectors are under the plenum. I would prefer not to remove that unless absolutely necessary. When I removed the spark plug, there was no fuel odor as the engine was being cranked. I removed another plug immediatly after cranking and it was dry also.
May 5, 2011 at 5:52 PM
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GOLFNGUITARS
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I am able to get at 2 injectors without removing the plenum. I have no voltage at the connectors with the ignition key on. I tested for shorts, and both connectors are shorted. What's my next step? Again, I have spark and fuel pressure.
May 7, 2011 at 8:21 PM
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OBRIEN 22407
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hey i had the same problem as well. and have changed everything. come to find out that the reason the injectors are not firing is because if one injector goes bad on your car it sends a single to the computer telling it to not respond. which cause the injector wires to have no voltage to them. need to take the top plenum off and test each injector with a volt meter. need to turn volt meter to 2000k on ohm then test each injector they should test the same if one or two reads different then they are the ones that are bad.
Sep 21, 2012 at 2:00 AM
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GOLFNGUITARS
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Yes, you are correct. Last year I solved the problem by removing the plenum and testing the fuel injectors with an ohm meter. One was shorted. I installed a new fuel injector and all is well. A year later, I decided to change all the fuel injectors as well as the fuel pressure regulator, and the car idles remarkably well. Probably the best it ever has since new.
Sep 21, 2012 at 3:52 AM
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