C4 won't start without Starting Fluid
Team Owner
Joined: Jul 2004
Posts: 28,462
Likes: 3,288
From: Hartford WI
Burning Brakes
Joined: Oct 2017
Posts: 823
Likes: 106
From: Somewhere near Fort Wayne, Indiana
@64Scout You are correct. Per the FSM, ECM closes the fuel pump relay if pulses from the ignition are detected. In parallel, the oil pressure switch also provides power when pressure is reached. Either will run the pump. ECM turns off the pump after 2 sec. if no pulses detected. Turning the key to "on" will run the pump for 2 sec. and charge the fuel system. Calling this "priming" is not a bad description.
Burning Brakes
Joined: Nov 2016
Posts: 761
Likes: 79
From: Buchanan GA
Well, I can promise you that my L98 sure didn’t like to start even here in the Georgia summer when that 9th injector wasn’t working. I am well aware that they were all batch fire until the LT-4 came on the scene.
Thread Starter
Intermediate
Joined: Dec 2013
Posts: 28
Likes: 5
Update...
Installed the new pump and it works well!
Even with my weak battery, I get 40 psi during the 2 second initial pump cycle in the "on" position
Then the engine starts immediately once I turn to "start". Then, the "at-idle" pressure is reduced by the regulator to about 32 psi.
Revving the engine takes it back to 40 psi.
Hardest part of the job was getting the 26 year old fuel hoses off of the pipes. Thankfully I have a pair of external retaining ring pliers I bought 30 years ago.
I was able to use them to push the hose off of the pipe with these. (These are the inverse of pliers. Squeeze them and the open and have big flat thin "jaws").These pliers come in handy for lots of things!
Installed the new pump and it works well!
Even with my weak battery, I get 40 psi during the 2 second initial pump cycle in the "on" position
Then the engine starts immediately once I turn to "start". Then, the "at-idle" pressure is reduced by the regulator to about 32 psi.
Revving the engine takes it back to 40 psi.
Hardest part of the job was getting the 26 year old fuel hoses off of the pipes. Thankfully I have a pair of external retaining ring pliers I bought 30 years ago.
I was able to use them to push the hose off of the pipe with these. (These are the inverse of pliers. Squeeze them and the open and have big flat thin "jaws").These pliers come in handy for lots of things!
Safety Car
Joined: May 2001
Posts: 4,757
Likes: 1,647
From: Fairfax Virginia
Hello again 49er,
It is great that your fuel pump is working properly now! Having the right fuel pressure is CRITICAL to these beasts.
While working on my older Corvettes I have become really good at stuck fasteners. I use something called KROIL OIL that I buy from Eastwood. Using Kroils and heat will take virtually any fitting off or loosen any bolt. The trick is to use heat to help the penetrating oil to be pulled in. I use a torch normally for a little heat but a hot air gun will do the trick in a heartbeat. Keep a fire Extinguisher handy so your pride and joy doesn't burn. I soak the fitting the day before and then soak it again and heat it up then wait a few minutes and all is done.
By the way, replace any hose that is thirty years old! On my 1988 the fuel line rusted shut internally. What fun it was to figure that one out. It sounds like you know what you are doing but just in case I will list the three most valuable tools for owning a C4 Corvette.
1. Factory Service Manuals
2. Fuel pressure gauge set
3. Volt Ohm meter
And a bucket of money never hurts either
Good Luck and enjoy your Running Corvette for all it is worth! It should run really nicely now so get out there and enjoy that Beautiful Corvette!
Best regards,
Chris
P.S. Thanks for telling us what was wrong and how you fixed it!
It is great that your fuel pump is working properly now! Having the right fuel pressure is CRITICAL to these beasts.
While working on my older Corvettes I have become really good at stuck fasteners. I use something called KROIL OIL that I buy from Eastwood. Using Kroils and heat will take virtually any fitting off or loosen any bolt. The trick is to use heat to help the penetrating oil to be pulled in. I use a torch normally for a little heat but a hot air gun will do the trick in a heartbeat. Keep a fire Extinguisher handy so your pride and joy doesn't burn. I soak the fitting the day before and then soak it again and heat it up then wait a few minutes and all is done.
By the way, replace any hose that is thirty years old! On my 1988 the fuel line rusted shut internally. What fun it was to figure that one out. It sounds like you know what you are doing but just in case I will list the three most valuable tools for owning a C4 Corvette.
1. Factory Service Manuals
2. Fuel pressure gauge set
3. Volt Ohm meter
And a bucket of money never hurts either
Good Luck and enjoy your Running Corvette for all it is worth! It should run really nicely now so get out there and enjoy that Beautiful Corvette!
Best regards,
Chris
P.S. Thanks for telling us what was wrong and how you fixed it!
Team Owner
Joined: Jul 2004
Posts: 28,462
Likes: 3,288
From: Hartford WI
Hello again 49er,
It is great that your fuel pump is working properly now! Having the right fuel pressure is CRITICAL to these beasts.
While working on my older Corvettes I have become really good at stuck fasteners. I use something called KROIL OIL that I buy from Eastwood. Using Kroils and heat will take virtually any fitting off or loosen any bolt. The trick is to use heat to help the penetrating oil to be pulled in. I use a torch normally for a little heat but a hot air gun will do the trick in a heartbeat. Keep a fire Extinguisher handy so your pride and joy doesn't burn. I soak the fitting the day before and then soak it again and heat it up then wait a few minutes and all is done.
By the way, replace any hose that is thirty years old! On my 1988 the fuel line rusted shut internally. What fun it was to figure that one out. It sounds like you know what you are doing but just in case I will list the three most valuable tools for owning a C4 Corvette.
1. Factory Service Manuals
2. Fuel pressure gauge set
3. Volt Ohm meter
And a bucket of money never hurts either
Good Luck and enjoy your Running Corvette for all it is worth! It should run really nicely now so get out there and enjoy that Beautiful Corvette!
Best regards,
Chris
P.S. Thanks for telling us what was wrong and how you fixed it!
It is great that your fuel pump is working properly now! Having the right fuel pressure is CRITICAL to these beasts.
While working on my older Corvettes I have become really good at stuck fasteners. I use something called KROIL OIL that I buy from Eastwood. Using Kroils and heat will take virtually any fitting off or loosen any bolt. The trick is to use heat to help the penetrating oil to be pulled in. I use a torch normally for a little heat but a hot air gun will do the trick in a heartbeat. Keep a fire Extinguisher handy so your pride and joy doesn't burn. I soak the fitting the day before and then soak it again and heat it up then wait a few minutes and all is done.
By the way, replace any hose that is thirty years old! On my 1988 the fuel line rusted shut internally. What fun it was to figure that one out. It sounds like you know what you are doing but just in case I will list the three most valuable tools for owning a C4 Corvette.
1. Factory Service Manuals
2. Fuel pressure gauge set
3. Volt Ohm meter
And a bucket of money never hurts either
Good Luck and enjoy your Running Corvette for all it is worth! It should run really nicely now so get out there and enjoy that Beautiful Corvette!
Best regards,
Chris
P.S. Thanks for telling us what was wrong and how you fixed it!
