Upgraded Fuel Pump for 1990 SCSB 5.7

[SuperSpore]

I need to upgrade the fuel pump to something better. It's hard to start, and the fuel pump is due to go out.
I did some research some time ago, some shops were recommending a 1996 vortec fuel pump ACDelco ep381, because it will increase LPH, and solve some issues.
Will there be an difference on the install, or will it swap in the same as the standard pump?
thanks

 

[someotherguy]

Before throwing parts at it, some troubleshooting would be wise. You may not have a fuel delivery problem at all.

As far as the '96 pump, that is a much higher pressure pump; I would not even consider it unless you had extensive engine mods and had an adjustable pressure regulator on your TBI unit. The Vortec pressure spec is 58~62 psi.. your TBI is 9~13 psi.

Get a good quality pump (AC Delco or Delphi only) spec'd for your specific application. Also get the new strainer sock, and a new filter. Be 100% sure you replace the short section of rubber hose between the pump and sender with hose included with the pump; if you use the wrong hose here the fuel will eat it quickly and you'll be pulling it again soon.

Richard

 

[SuperSpore]

Thanks for response.
The trouble shooting is in needing to change it every few years, on every obs truck I've had. There has to be a better pump, or a known solution for this.
I normally ignore the symptoms, wait until they fail, and need to tow it and I end up pulling the gas tank with a lot of fuel in it.
I want to try something new this time. lol

 

[someotherguy]

Lift the bed this time instead. No need to drop the tank. There's a number of ways you can do this; some use a big block of wood and jack the front of the bed up after removing all the bolts and loosening the rearmost ones but leaving them threaded in, to prevent it from sliding backwards. Instead of a jack you can use an engine hoist. You can use ratchet straps suspended over garage rafters or a strong tree limb (USE ALL NECESSARY CAUTION and do not put your body under the bed until you have a secondary securement method like jack stands.) I have done several short beds by crossing ratchet straps in an X in the stake pockets and lift the center with an engine hoist.

If you must drop the tank for whatever reason (bed bolts rusted to hell, or in other people's case it's an SUV, etc. etc.) then spend a few bucks on a cheap siphon bulb hose and you can drain the tank into however many 5 gallon cans you need to; makes it so much easier to handle an empty tank.

Richard

 

[evilunclegrimace]

Thanks for response.
The trouble shooting is in needing to change it every few years, on every obs truck I've had. There has to be a better pump, or a known solution for this.
I normally ignore the symptoms, wait until they fail, and need to tow it and I end up pulling the gas tank with a lot of fuel in it.
I want to try something new this time. lol

If you are only getting a few years out of a pump, there has to be a reason that they are failing. Try cleaning the tank out making sure that there is not any water or sediment in the tank. You can do this by Jacking the truck up so that the front end is higher than the rear and that will cause and water to go to the back of the tank and then you can siphon the water and any sediment out even if the tank is full

 

[Dropped88]

You can run the vortec pump on the tbi without any issues it helps fix a lot of the fuel volume problems with TBI under hard throttle.

And the regulator has no issues with holding the proper pressure

 

[Schurkey]

Thousands of years ago, the "hot setup" as espoused by another forum was to replace the TBI pump with the ACDelco EP241. Supposedly "fixed" all sorts of problems with the TBI pump.

I crammed the '241 into my '88. Been there for years. Works great. Downside is the pump outlet is not the same size as the TBI pump outlet, so the hose connecting the pump to the rest of the hanger tubing gets stressed some. There is no concern at all about the OEM regulator being able to control fuel pressure.

I'd use the Vortec pump if I were doing that job again. Hopefully, the pump outlet size is the same as the hanger tube size, so the hose is a simple fit. Use "Fuel Injection" clamps instead of those hateful non-shielded worm-gear disasters. And the hose itself is "special" because it's rated for submerged-in-gasoline use.

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If your fuel pumps are only lasting a couple of years, SOMETHING ELSE IS WRONG.

1. I always install an in-tank wire harness to replace the (typically corroded) wires inside the tank.

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The new harness is often "generously" sized. It's like spark plug wire kits--the replacement wires are always longer than the OEM wires.

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2. Always clean the inside of the tank. Contamination--rust particles, dirt, grit, and water--are the leading cause of in-tank fuel pump failure. And always install a new filter sock on the new pump.

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3. I refuse to replace an in-tank fuel pump without verifying AT LEAST the voltage supply to the pump, as close to the pump as practical; and verify the voltage on the ground wire as close to the pump as practical, WITH THE PUMP RUNNING (assuming it runs at all.) Better still is to verify voltage AND amperage draw. And the best-possible diagnosis is to use a low-amperage probe connected to an oscilloscope, which then allows you to examine the current draw of each individual bar on the fuel pump motor armature, and calculate the fuel pump RPM.

Low supply voltage--or high resistance on the ground side--makes the fuel pump motor run slowly, reduces fuel pressure, and in general is bad for the fuel pump.

4. New fuel filter with a new fuel pump. Restriction in the fuel supply makes life hard on the pump, causing excess wear and higher operating temperature.

 

[PlayingWithTBI]

I'd use the Vortec pump if I were doing that job again. Hopefully, the pump outlet size is the same as the hanger tube size, so the hose is a simple fit.

Yes. the EP381 from a 96 Vortec is a direct fit plus the one I got came with the hose too.

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[SuperSpore]

Thanks for the responses.

 

[SuperSpore]

If it matters to anyone, I did the EP381 install and it was a direct fit with no issues.
It solved the hard starting problem, and it is more responsive.
Totally worth for me.
Thanks to everyone that replied.