I have an 89 pickup 4wd- 22RE engine. It is very hard to start when it's cold (<25F) outside. If it starts and is warmed up it always starts and runsgood. When it's cold, the engine will just crank, but not start. The cylinders do not fire at all. Then after 5 min or so it suddenly starts and runs fine. I'm afraid it won't start at all one of these cold days. Is there a thermal sensor or something like that, that may be acting up? Is this a fuel injector problem? The distributor rotor , spark plugs and wires were changed last month. The connections look good. Thanks for your response.