Inline Fuel Pump Question

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08-15-2015
Boulky12

Inline Fuel Pump Question

I'm swapping a Vortec 350 w/4l80e in my 93(originally 2.8 tbi/5 speed)

Motor and Tranny are in. Now I'm on fuel delivery.

Originally I was planning on just swapping the fuel pump from the donor truck but its way bigger than the stock tbi pump and wont fit in the tank.

So now I'm thinking to run the stock tbi pump with an inline pump such as this one: http://www.summitracing.com/parts/vp...91bx/overview/

This pump has maximum of 85 psi. The CSFI injection runs at about 60-65.

So can I just install one of these with a regulator and I'll be good to go?

Really appreciate the help. Thanks
08-16-2015
Bigdav160

You're not going to be able to suck through the old pump. That means you'll need to extend your pickup tube.

I can't say I've ever noticed one fuel pump being much different in size than others. I believe the ACDelco ep381 is a popular choice for in-tank pump with a Vortec.

Your vortec injection has a pressure regulator inside the intake manifold
08-16-2015
Boulky12

Quote:

Originally Posted by Bigdav160

You're not going to be able to suck through the old pump. That means you'll need to extend your pickup tube.

I can't say I've ever noticed one fuel pump being much different in size than others. I believe the ACDelco ep381 is a popular choice for in-tank pump with a Vortec.

Your vortec injection has a pressure regulator inside the intake manifold

I dont understand this. Are you saying stock tbi pump is not going to keep up feeding the inline pump? Can you clarify.

The fuel pump from the Full size was way bigger than the s10 fuel pump.

The regulator inside the intake will automatically regulate the pressure?

That little thing is an in-tank pump?
08-16-2015
Nasty-Z

Depending on what year the donor truck was the sender assembly will be different that the earlier years , i.e , it will be a pump assembly and will not fit the earlier tanks .

If I was doing the conversion I would run a aftermarket Walbro 255 such as the GSS340 or even the Airtex E3270 will be fine for your swap , both should be less than $100 depending on where you buy.

I am not a fan of external pumps , they are in the tank for a reason , keep it there .

TOM
08-16-2015
Boulky12

Quote:

Originally Posted by Nasty-Z

Depending on what year the donor truck was the sender assembly will be different that the earlier years , i.e , it will be a pump assembly and will not fit the earlier tanks .

If I was doing the conversion I would run a aftermarket Walbro 255 such as the GSS340 or even the Airtex E3270 will be fine for your swap , both should be less than $100 depending on where you buy.

I am not a fan of external pumps , they are in the tank for a reason , keep it there .

TOM

Donor truck is a 2000 (Gmt400) 3/4 ton.

So any of those pumps you mentioned will fit in the stock S10 Gas Tank?
08-16-2015
Nasty-Z

Quote:

Originally Posted by Boulky12

So any of those pumps you mentioned will fit in the stock S10 Gas Tank?

Yes sir , I run the GSS340 in my '92 S10 , It has been there from the beginning , TPI350 , Carb 383 , now a TBI 434 . Absolutely no fuel pressure problems.

I have the E3270 in my Blazer with the TBI 496 as it what was in stock when I did the tank , no problems there either .

Before you say they are TBI , I run more TBI pressure than most ................ They work.

Be sure you get the filter sock for the Walbro if you go that route , it is larger than stock so a different filter is required , the bottom of the hangar needs to be "massaged" a bit but fit and function is fine.

TOM
08-16-2015
Boulky12

Quote:

Originally Posted by Nasty-Z

Yes sir , I run the GSS340 in my '92 S10 , It has been there from the beginning , TPI350 , Carb 383 , now a TBI 434 . Absolutely no fuel pressure problems.

I have the E3270 in my Blazer with the TBI 496 as it what was in stock when I did the tank , no problems there either .

Before you say they are TBI , I run more TBI pressure than most ................ They work.

Be sure you get the filter sock for the Walbro if you go that route , it is larger than stock so a different filter is required , the bottom of the hangar needs to be "massaged" a bit but fit and function is fine.

TOM

Awesome. Thanks for you help bud
08-16-2015
Xnke

You won't have any issues running an inline pump *in addition* to the stock pump. You can't just run the inline pump and NOT run the stock pump, though.

There's no reason to not run the inline pump if you already have one, but if you are dropping the tank then just get the in-tank pump, it's quieter, smaller, and does not involve any extra wiring. Just a cleaner install all around.
08-19-2015
Hog

Yes, the Vacuum Referenced Fuel Pressure Regulator which is located in the intake plenum will control the fuel pressure to keep it within the stock 60-66psi range.

The 4l80e will be a tight fit, its a rather large trans in an S-10.

peace'
Hog
08-19-2015
Boulky12

Quote:

Originally Posted by Hog

Yes, the Vacuum Referenced Fuel Pressure Regulator which is located in the intake plenum will control the fuel pressure to keep it within the stock 60-66psi range.

The 4l80e will be a tight fit, its a rather large trans in an S-10.

peace'
Hog

Thanks and yeah getting that trans in was a real pain in the ass. It's a super tight fit but its in and I didn't have to cut my floor up at all.