Cranking Engine for too Long Before It Starts

[dyeager535]

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another thing you guys need to look into is the oil pressure sending unit. it "shouldn't" allow it to start until a certain amount of oil pressure is built up.

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No, thats if the fuel pump relay fails. If it took oil pressure (the switch requires around 5 psi) to start, EVERY start would take a long time, and GM didn't design the systems that way.

I'm not sure what would happen if you *disconnect* the temp switch connector. Jumping the two wires makes it go "full hot". If the ECM looks at voltage to throw a code as well, instead of ONLY using voltage to determine engine temp, then this won't work, but it won't hurt anything either. Just try it on a cold engine. Scanner would still tell you right off the bat what the sender is telling the ECM the engine temp is.

 

[hawkeye649]

Sounds too meeee like a failed fuel system relay and that your truck is running on your oil pressure switch.

First thing first, old trucks can have allot of crap that mysteriously appears in the tank. Pull the fuel filter and see if it's clean.
Have you taken a preassure reading of the lines to see if it's up to snuff? I can dip into my 1991 gm service manual to see what "acceptable" PSI is but I think it to be around 44PSI.
If you have tested it, did you turn it to RUN, let it prime, and leave it over a 15min period? Did it hold pressure?
This is would rule out a ruptured fuel pressure diaphragm...

I wouldn't "accet" 4-5 seconds. I'm thinking of trying to trouble shoot why my rig takes up to 1 second, it's annoying. It used to be as fast as you could turn & release the key.

 

[70~K5]

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I wouldn't "accet" 4-5 seconds. I'm thinking of trying to trouble shoot why my rig takes up to 1 second, it's annoying. It used to be as fast as you could turn & release the key.

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My '95 454 TBI motor has always taken about 5/6 turns before it would fire fom new. I've just asumed that's the way it is with FI. Now with a carb motor, give it a couple of shots from the acecelerator pump and it would fire real fast. /forums/images/graemlins/thumb.gif

 

[84_Chevy_K10]

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I wouldn't "accet" 4-5 seconds. I'm thinking of trying to trouble shoot why my rig takes up to 1 second, it's annoying. It used to be as fast as you could turn & release the key.

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My '95 454 TBI motor has always taken about 5/6 turns before it would fire fom new. I've just asumed that's the way it is with FI. Now with a carb motor, give it a couple of shots from the acecelerator pump and it would fire real fast. /forums/images/graemlins/thumb.gif

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That's the way my TBI rig has always been as well. Unless my K10 with the Q-jet sits for a week or something, it fires immediately.