Cold start issues

[DTOWNZ]

I have a 1997 chevy 1500 that won't start without starting fluid first thing in the mornings. Once I get it cranked up and it runs a couple of minutes then it will start up every time with no problem. I have had the truck for almost a year and this has been an issue for quite some time now. My question is "what can be causing this problem"? I have yet to test the fuel pressure but am wondering if this could be due to a bad fuel pressure regulator.

 Thanks for reading and any info on this would really help a Bow Tie guy out.

 By the way the engine is a 4.3 Vortec

[Justin101714]

Get a pressure gauge on it. Turn the key on, after a minute the pressure shouldnt drop significantly. If it does, you know you have a regulator problem. You also need to check the fuel volume while you’re at it. You could have pressure but low volume


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[DTOWNZ]

4 minutes ago, Justin101714 said:

Get a pressure gauge on it. Turn the key on, after a minute the pressure shouldnt drop significantly. If it does, you know you have a regulator problem. You also need to check the fuel volume while you’re at it. You could have pressure but low volume


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Thank you for the reply but how do I go about testing volume?

[Justin101714]

The gauge should have a button on it releases fuel as the engine is running. Drain this fuel into a graduated container. I’ll get the spec soon. I’m almost at work


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[Jsdirt]

Yep, my guess is either the regulator, or the pump itself is tired.

[Justin101714]

Also let’s not forget the possibility of a restricted fuel filter.

 

Okay, around 50-60 psi of pressure while cranking the engine.

 

Key on engine off 60-66 psi

 

Didn’t find specs on volume yet. Still looking. If you pressure is below 50psi while cranking, replace the pump. The spider system under the intake just doesn’t like less than 50.

 

 

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[DTOWNZ]

8 minutes ago, Justin101714 said:

Also let’s not forget the possibility of a restricted fuel filter.

 

Okay, around 50-60 psi of pressure while cranking the engine.

 

Key on engine off 60-66 psi

 

Didn’t find specs on volume yet. Still looking. If you pressure is below 50psi while cranking, replace the pump. The spider system under the intake just doesn’t like less than 50.

 

 

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Yeah I was looking online that it needs at least 50 psi. So I am going to get a presure tester today.

[Doug_Scott]

Do you hear the fuel pump when you turn the key on first thing in the morning?  To me, this sounds like the fuel pump timer that is used on startup is not doing its job.  Fuel pumps are generally only active when engine is running.  This safety item is bypassed when key is turned on before engine starts.  Listen for fuel pump before cranking the engine over.  It should run for at least 10 seconds with key on, engine off. 

[DTOWNZ]

2 hours ago, Doug_Scott said:

Do you hear the fuel pump when you turn the key on first thing in the morning?  To me, this sounds like the fuel pump timer that is used on startup is not doing its job.  Fuel pumps are generally only active when engine is running.  This safety item is bypassed when key is turned on before engine starts.  Listen for fuel pump before cranking the engine over.  It should run for at least 10 seconds with key on, engine off. 

Yes the pump runs when key is turned on it just won't start without a shot of starting fluid first.

 

[Jsdirt]

Fuel pressure & volume test first, and if that checks out, then you have an air leak somewhere.

 

Fuel pressure would be the first place I'd start if this was in my shop, and then go from there.