Try connecting a voltmeter OR test light to the plug on the cold start injector & operate the starter. UP to 60F there should be a voltage signal for at least 1-2 seconds. WITH a cold motor (30F) the signal should last 10 sec durning starter operation.

THE coolant temp sensor can also cause hard cold starting.
AT 65-70F the resistance should be around 2500ohm.

ALSO have the valves been adjusted lately?? Tight intakes will make the engine hard to start as well.

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