2000 GMC Sonoma difficult to start

start
sonoma

#1

3 times when allowed sit from Friday evening until Monday morning and having less than quarter tank of gas, pickup was extremely difficult to start. Almost ran battery down and had to sweat bullets, wait some time and keep trying. All other times starts beautifully and runs smoothly. 50K miles. Passed CA inspection 2 months ago. Driveway has slight slope (less than 10 degrees).


#2

Sorry. I forgot to include my question. Does anyone know what might be the cause? Is it something to do with fuel line…vacuum…fuel pump? Any thoughts would be appreciated.


#3

Have some troubleshooting supplies (starting fluid, spare spark plug, and timing light) available. When the engine is slow to catch, spray some starting fluid into the intake. If the engine catches for a bit and then dies, you should look at the fuel system. Check fuel pressure. If the engine does not catch, take off one of the spark plug wires; insert the spare spark plug; ground the base; and see if you have a strong blue-white spark. If you have spark, attach the timing light, and see where the timing mark falls with respect to where it did on a successful start. All of this should steer you closer to determining which road to head down on trouble shooting.

Post back your results and we can help further.