97 Tahoe hard to start.

I have a 97 Chevy Tahoe with a Vortec V8 and it wont start while cranking. I can crank the motor with the key and it wont start but when I let the key off its as if the motor catches and starts on the last spin after letting the key off. I can spray starter fluid in th intake and crank and it will start while cranking. when i turn the key to the "on" position (dash light on but not cranking) I can hear the fuel pump run for a couple of seconds and then stop. I have replaced the oil sending unit and the fuel pump relay. Once it starts it drives fine and does not hesitate, lack power or stall. I can drive on the streets and highway just like normal. If I park it and let it set for any more than 5 to 10 minutes I have to use the starter fluid to get it started. I will be checking the fuel pressure while cranking and would like to know what the pressure should be while cranking and then while running. I have checked to see if I have spark and could swear that I do but I am going to check again just to be sure. Any other ideas for what to look for? Thanks for your help in advance.

i would replace the fuel filter first since it's cheapest and if that doesn't work then your fuel pump may not be putting enough pressure you have to test it and see how much psi it's putting out should not be lower than 31 if so you have a weak pump and it will need to be replaced, Good Luck and :welcome:

sounds like a dead spot in your keyswitch. next time you crank the engine try backing off on the key a little bit. as keyswitches wear you tend to lose your constant on when the key is turned all the way

makosnax said:

sounds like a dead spot in your keyswitch. next time you crank the engine try backing off on the key a little bit. as keyswitches wear you tend to lose your constant on when the key is turned all the way

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I second that. It definitely sounds like an electrical issue to me.

I'm pretty cheap sometimes, had a 98 jimmy that had a bad ign switch, pulled it apart and filed the contacts down to fix it......

Check fuel pressure and take voltage readings across the ign siwtch....