No fuel pressure=no fuel=no start! 
Lost
Thread Starter
Cruising
Joined: Oct 2009
Posts: 13
Likes: 0
From: camp lejeune NC
Lost
I have a 1986 that absolutly does not want to start when cold. With a couple shots of starting fluid, it starts right up. Should I start with the cld start injector? The second half of this story is that when I turn the key to the on position, Sometimes I hear the fuel pump running and sometimes I dont?
Team Owner
Joined: Jan 2003
Posts: 20,335
Likes: 264
From: Summerland B.C. Canada
I would diagnose the fuel pump relay circuit. It sounds like you may be powering the fuel pump via the oil pressure switch. Here is some good reading, you will a PDF reader, such as Adobe.
http://members.shaw.ca/agent86/Fuel%...elivery-8A.pdf
http://members.shaw.ca/corvette86/Co...0View%2086.pdf
http://members.shaw.ca/corvette86/Fu...mDiagnosis.pdf
http://members.shaw.ca/corvette86/Fu...l%20System.pdf
http://members.shaw.ca/agent86/Fuel%...elivery-8A.pdf
http://members.shaw.ca/corvette86/Co...0View%2086.pdf
http://members.shaw.ca/corvette86/Fu...mDiagnosis.pdf
http://members.shaw.ca/corvette86/Fu...l%20System.pdf
Team Owner
Joined: Jan 2009
Posts: 73,568
Likes: 33
From: Somewhere in Mo
St. Jude Donor '09-'10, '14
Be more specific on sometimes you hear the pump run. Do you hear the pump run the first time you turn the key on, or just sometimes?
Could be the circuit, could be the relay is going bad and could be in the pump itself. You'll have to do a complete pressure test of the fuel system to determine if it's fuel related.
And of course it could be the cold start injector. If it starts with ether it sounds more like a fuel delivery issue to me.
Could be the circuit, could be the relay is going bad and could be in the pump itself. You'll have to do a complete pressure test of the fuel system to determine if it's fuel related.
And of course it could be the cold start injector. If it starts with ether it sounds more like a fuel delivery issue to me.
Melting Slicks
Joined: Feb 2006
Posts: 2,753
Likes: 15
From: backwoods upstate ny
check fuel pressure to see if this might be your doll's heart ache.
Thread Starter
Cruising
Joined: Oct 2009
Posts: 13
Likes: 0
From: camp lejeune NC
Thanks for the ideas on where to start. I should have been clearer. when I turn the key on, i dont hear anything for the first few times I try to start it and then out of the blue, I hear the pump running.
Drifting
Joined: Jun 2010
Posts: 1,853
Likes: 8
From: Westerly RI
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Thread Starter
Cruising
Joined: Oct 2009
Posts: 13
Likes: 0
From: camp lejeune NC
No, I still have to spray it with starting fluid. After it starts, it runs great. I can take over countries with no problem but I am no mech. I know the components pretty good but dont know troubleshooting real well.
Race Director
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
Do what Agent said first....
It sounds like your fuel pump relay has failed. In that case, the oil pressure switch should act as a backup and energize the pump once about 4 psi is reached during cranking....unless it has failed as well....or your car is taking a long time to build oil pressure for some reason during cranking. By spraying ether in the throttle body, you're able to start the engine, thus building oil pressure rapidly and closing the fuel pump circuit. My concern is why isn't this happening during cranking? Granted, it will take longer to start the car, but it should start. How many miles are on this engine, and how much oil pressure do you normally see at idle?
It sounds like your fuel pump relay has failed. In that case, the oil pressure switch should act as a backup and energize the pump once about 4 psi is reached during cranking....unless it has failed as well....or your car is taking a long time to build oil pressure for some reason during cranking. By spraying ether in the throttle body, you're able to start the engine, thus building oil pressure rapidly and closing the fuel pump circuit. My concern is why isn't this happening during cranking? Granted, it will take longer to start the car, but it should start. How many miles are on this engine, and how much oil pressure do you normally see at idle?