2000 sonoma troubles..4.3L

[skaz]

hard starting when cold (if at all)..it has a brand new fuel pump ..coolant temp sensor the complete distributer has been replaced ..mass air flow sensor good tune up the computer has been checked by warming it up then put back in cold truck.. once in a while it will start if the key is only turned for a split second? if it's held any longer reguardless if it has been previuosly running it will crank forever..possibly the ignition switch? why only during cold weather?..near my wits end

 

[Molson02536]

hard starting when cold (if at all)..it has a brand new fuel pump ..coolant temp sensor the complete distributer has been replaced ..mass air flow sensor good tune up the computer has been checked by warming it up then put back in cold truck.. once in a while it will start if the key is only turned for a split second? if it's held any longer reguardless if it has been previuosly running it will crank forever..possibly the ignition switch? why only during cold weather?..near my wits end

Re check your fuel pressure at the shredder valve, Vortec engines need 61 to 66 psi (or maybe get by with a little less) .. even if you can 'hear' the fuel pump runs it may not provide adequate fuel pressure. You did mentioned that it's a new pump so re check the ground wire to the fuel sending unit. A bad ground will cause you to have a weak pump pressure.

Keep us posted and good luck.

 

[cody123]

i has the same problem it turned out my fuel pressure regulator went bad and it only got worse as it got colder its all part of the spider injection system

 

[skaz]

turns out it was the ignition switch it would be fine if it was warm weather but once it got cold out it ...............it acted up /thanks all