threads
Page 1 of 1
Full Size Truckin General \  need help with sbc 350

need help with sbc 350

Full Size Truckin General General Discussions
views 405
replies 9
following 4
 
jreme34   +1y
i put a short block 350 in my 90 fullsize i have edlebrock 4 barrel carb and my issues are when i turn the key my adjustable regulator shoots up to 6lbs of pressure and the carb get the first shot of fuel then the regulator falls to 0. the truck will start and run for a few min and then die i have replaced the fuel pump and played with the regulator so if anyone has had this problem or has any knowledge on this it would be greatly appreciated
unusualfabrication   +1y
You said when you turn the key the reg shoots up to 6 psi then falls to 0 psi, is the key just on or is the truck running when the pressure bleeds off? What fuel pump are you running? It sounds like the fuel pump isn't staying on so when the initial burst of fuel is gone the motor stalls...
jreme34   +1y
it is a stock internal fuel pump and it doesnt hold any pressure when it is running jus the first blast of fuel to the carb when u turn the key and it shoots to 6psi and falls to 0 even when running the gauge reads 0 well chris i was sure thats why i repalced the fuel pump this is my first engine build so i dont know what it could be....if it the regulator clogged carb or jus scrap internel stock pump and go with a external pump
unusualfabrication   +1y
Well it sounds like your getting fuel to the carb, if the regulator was clogged you won't have any fuel in the carb and it wouldn't run. When you turn the key to the on position it primes the carb, then when you turn the key to the run position the fuel pump should stay on. To me it doesn't sound like the fuel pump is staying on when the key is in the run position. You should be able to hear the fuel pump running so check for that (or have a friend check if you can't) after you start the truck. An easy way to check it is to take off the gas cap and listen to the filler neck after you've started the truck, you'll here the pump whining if its on.
jreme34   +1y
would there be any reason that the fuel pump would stop pumping like a fuse or relay? when you turn key to on position it kicks on i can hear it but not sure about when the truck is running if it staying on ill check tomorrow and get back with ya i appreciate the help
bodydropped   +1y
Edited: 11/19/2011 12:29:50 AM by bodydropped

you need to run a different fuel pump or rewire your stock one, the factory fuel pump setup is setup to when the keys on to turn on and once the motor is running it has a delay to run long enough that if it sees no oil pressure that the pump will shut off. till you get that problem fixed it will keep doing this
unusualfabrication   +1y
--------------------------------------------

bodydropped said:

Edited: 11/19/2011 12:29:50 AM by bodydropped

you need to run a different fuel pump or rewire your stock one, the factory fuel pump setup is setup to when the keys on to turn on and once the motor is running it has a delay to run long enough that if it sees no oil pressure that the pump will shut off. till you get that problem fixed it will keep doing this

--------------------------------------------

Thats right, I forgot this was a FI motor and you switched it to a carb.
jreme34   +1y
now that makes sense...i put a mechanical oil pressure gauge on it and it doesnt read any pressure there...what would be the best solution to rewire the fuel pump or get a different one and does anyone know how to rewire the stock one since it is brand new...and thank you tj ...like i said this is my first motor build
scottpow   +1y
The fuel juice runs through the oil pressure sender for safety reasons. If you have an accident you don't want the fuel to be pouring all over if the engine is dead but the key is still in on position. There is a solution I just can't remember off the top of my head.
jreme34   +1y
--------------------------------------------

scottpow said:

The fuel juice runs through the oil pressure sender for safety reasons. If you have an accident you don't want the fuel to be pouring all over if the engine is dead but the key is still in on position. There is a solution I just can't remember off the top of my head.

--------------------------------------------

that is another good point def dont want that and thanks for everyone so far for sharing their knowledge and if you can think of it lmk...any other ideas or knowledge would be much appreciated....
Page 1 of 1