97 Sierra K1500-Long Start After Warm
 

When truck sits for a long time, like over night, in the morning the engine will normally start. When I go to work and it sits all day it will start right up. If I drive somewhere, like the store, when I try to start it the engine will crank for about 10 seconds. If I go to another place it seems to get even harder to start. Seems the hotter it gets the harder it is to start. The engine is cranking normally just not catching fast. Tune up was done last summer. New everything. Some times the engine will make a loud pop, like a backfire, after it's been run around for a while. Anyone have any thoughts? Truck has 170,000 miles. Runs fine once it's started.

Fuel pressure regulator....its under the upper plenum...around $60

leaky injectors

I'll start with the regulator first. I was leaning toward a fuel problem. Put in new filter last summer so figured it wasn't that. Had a new pump put in a few years ago and I can hear it when the key is turned. Thanks

9 years later....
 

Check you starter amps on restart, if they are high that could be your problem. Replace the bulky starter....