Oldsmobile Cutlass Sierra 1991

How long since a tune-up? Any applicable mil codes? When the problem occurs, if it cranks good but won't start, have a helper crank it, while you visually check for spark at the plugs. If you have spark everywhere use a gage and check fuel pressure. Find out what your missing when the problem is ongoing, spark--fuel-- whatever. You can check for spark by using a known good plug or spark tester. You pull plug wire loose from spark plug, stick spark tester in plug boot, ground metal part of tester to metal part of engine. Engine cranking watch for spark.

To check mil codes, use jumper wire between A & B terminals of datalink connector located, probably at lower edge of dash. Then turn the key to on, no further, no crank. The mil should start flashing, you count the flashes to get the codes. Your looking for two digit codes.