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Discussion Starter · #1 ·
I have a 95 caprice with a 4.3
I just replaced the fuel pump,sock and filter.
Now the car starts but only with extended cranking almost like its sucking the fuel up instead of pushing it.
I can hear the fuel pump prime when I turn the key.
I think I have to start from zero so hopefully someone can help with my questions?
Which wire in the weatherpack connector should have 12 volts?
Where is the regulator at?

Thanks
 

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IIRC the purple wire should have 12 volts, the pressure regulator is on the fuel rail on the drivers side. Get a fuel pressure gauge and check fuel pressure for low pres. or dropping pressure, which would indicate a problem with pump, check valve in tank, or leaking injector(s). hth
 

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Purple wire is for the fuel gauge. Gray wire is for pump power, and will only have voltage for a second or two while the key is turned forward or until car is running (then power will be constant). If you can hear the pump priming, power is not the issue. Maybe there is a problem with the flexible hose inside the tank (Kinked or leaking) causing you to lose pressure. Check fuel pressure with a test gauge. Should at least be 38lbs or better when key is turned on. If pressure is lower, or quickly drops, then it's time to drop the tank again.... Did you replace the wiring inside the tank for the fuel pump? The connections have a history of overheating and melting, and not making good contact...
 

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Discussion Starter · #4 ·
K so here goes:

I checked fuel pressure today and it reads 38 lbs with the key turned to start(priming)
soon as its done priming I start losing pressure pretty quickly!
Like if I left the key on without cranking it will be back at zero in about 10-15 seconds.
If I turn it to crank the pressure builds up and when it hits around 40lbs the car will start and it maintains 38lbs the whole time.
I did not replace the flexible hose in the tank cause I thought it wasnt replaceable
I admit I didnt search till i was done reinstalling the tank and had problems.

Any ideas what to check or replace next I really dont want to take the tank down again unless I have to???????
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Could just be a defective fuel pump. They have an anti drain back valve built in which maintains pressure when you prime the system. If it's bad, you'll lose pressure just like you are describing. You can drive it like this for awhile. I drove a car for a year like that. If you turn the key on and off a few times before starting, I bet it'll start right up every time. But you're gonna have to drop the tank again to fix it right though. Hope you got a warranty on the pump. Also check the wiring harness inside the tank for signs of melting at the connectors while its down. Check condition of the flex hose and make sure it's seated tightly on the pump (before returning the fuel pump). Make sure the hose isn't gonna kink when you reinstall the sending unit.

Not sure if the flex hose is available separately from the sending unit. Maybe someone else here will post some info on it
 
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