car wont start when cold

When the problem occurs, I'd have to do some basic tests. 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. Any applicable trouble codes? How long since a tune-up?

To check for spark, you can use a known good spark plug or spark tester. Pull spark plug wire loose from spark plug. Stick tester in the plug boot. Ground/touch metal part of tester to metal part of engine, engine cranking watch for spark, check more than one plug wire.