Fuel pump stays on

[BigIron002]

Hey just threw a 383 in my 93 Suburban and now the fuel pump stays in been fighting it and no change. Seems to run alright feels doggy not anything better then the old 350 that was pulled out and seems to want to die and hesitates. Any help is appreciated. Thank You

 

[GoToGuy]

Have to more specific, turn key to run, pump primes, then to to start, truck. Truck starts normally.
Since we can't see or hear it , ya tell us or describe what's going on.

 

[BigIron002]

When you hook the battery up and fuel pump is on key on key off it’s on. Only way to turn off is with the fuse be the relay. Unplug the relay and it’s on. Start up idles alright seems to wanna die out when your out driving around. Thank You

 

[PlayingWithTBI]

When you hook the battery up and fuel pump is on key on key off it’s on. Only way to turn off is with the fuse be the relay. Unplug the relay and it’s on. Start up idles alright seems to wanna die out when your out driving around. Thank You

Sounds like your Oil Pressure Shut Off Switch is either shorted out internally or the wires going to it are. It s/b on the China Rail near the distributor. Maybe the wires got pinched when installing the intake manifold.

What throttle body and fuel pump do you have? Are you getting enough pressure at idle and when under load.

 

[Caman96]

. ‘ , “ - ! : ; / - ’

 

[BigIron002]

All the stock put a new oil pressure sensor on while I was I was in there and set back to zero for base timing.

 

[Scooterwrench]

. ‘ , “ - ! : ; / - ’

I don't think they teach punctuation in schools anymore.

 

[Scooterwrench]

All the stock put a new oil pressure sensor on while I was I was in there and set back to zero for base timing.

AC Delco or elcheapo chinesium?

 

[Caman96]

I don't think they teach punctuation in schools anymore.

Nope, just indoctrination.

 

[PlayingWithTBI]

All the stock put a new oil pressure sensor on while I was I was in there and set back to zero for base timing.

There are only 3 ways to get power to the fuel pump -
1.) Through the Fuel Pump Relay. You disconnected the relay and it stayed on. Unless that wiring is shorted, we can move on.

2.) The Oil Pressure Switch is sending power to the fuel pump. It's wired to bypass the FP Relay as a backup. Try disconnecting it and see if the pump keeps running. Check the wires there too.

3.) by applying 12 VDC to one of the terminals (I forget which one, maybe pin "G" but, you can Google that) on the ALDL connector. This is the most unlikely cause.

You need to verify fuel pressure 1st, then get a scanner and look at what's going on - not just timing...