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1990 Buick Skylark Question: backfires and quits running

 

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mxdg74, Kelso, WA, March 15, 2009, 11:52
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I have a 1988 Buick skylark,the coils are good the o2 censor good,module good, new plug wires, new crank censor, fuel system checks ok. but it still back fires and dies, anyone know why.

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    dandd March 15, 2009, 12:33
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    This car had a pattern failure with Mass Air Flow Sensors, if it is a V6 engine. I worked at a GM dealership and we used to fill shopping carts every week with Bad Mass Air Flow Sensors from dying and back firing Buicks and Pontiacs. Do you ever have a Check Engine Light on? Get a scanner and look at the Grams per Second of Air going into the engine. It is usually listed as GPS on the data stream. When the sensor acts up, the data will go very, very high from say 4-6 grams at idle to over 20 or more. I am assuming that you output checked the coils, meaning that you are sure that they can put out 80,0000 volts, no problem. ( you can use a spark tester for this )Ohm checking them is very inconclusive. Also, you definitely need to have GM wires. Most after market wires will not handle the high voltage. You should also check your grounds, especially for the module and where it mounts. You should also check the idle air control counts, it should be about 20 in drive. If it is low 0-5, it can indicate a vacuum leak which will cause a lean misfire and potential dying. Theses are a few of the things to check for in these cars.

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