TBI to CSFI?

[Fast355]

^X2, to support the fuel demands I had to cannibalize a vortec sending unit for the pump and put it in my S10. which if you have the donor vehicle you could use the pump out of it. using a 4L80e will still need to be addressed but I think a couple of people cracked that nut with the 7427 computer on a newer 4l80e

After about 93 the 4L80Es are the same as the newer ones up to about 05ish. The TBI 5.7/4L80E came as a powertrain and used the 7427 pcm.

[Boulky12]

^X2, to support the fuel demands I had to cannibalize a vortec sending unit for the pump and put it in my S10. which if you have the donor vehicle you could use the pump out of it. using a 4L80e will still need to be addressed but I think a couple of people cracked that nut with the 7427 computer on a newer 4l80e

Dang well since I can't use the stock pump will the CSFI pump from the Full Size(donor) fit in the S10 Gas Tank?

Will the 4L80-E still be an issue even if I have the Harness and Computer from donor?

Thank you guys so much for the info.

[1project2many]

S10 wiring from 2.8 to 5.7 could require a bit of thinking but I'd also vote to go TBI. GM wiring for S10 trucks doesn't always match diagrams. Be prepared for some "What the heck?" moments. I believe the pcm from a 93 S10 with 4L60E and 4.3 is the same as the 94-95 V8 C/K trucks and if you get the TBI 4.3 V6 harness it should reduce the amount of rewiring necessary. You'll need a V8 chip (called a memcal) and you will need to find or build a calibration to burn onto the chip because the stock 5.7 TBI calibration is not correct for the L31 engine with TBI.

[Boulky12]

S10 wiring from 2.8 to 5.7 could require a bit of thinking but I'd also vote to go TBI. GM wiring for S10 trucks doesn't always match diagrams. Be prepared for some "What the heck?" moments. I believe the pcm from a 93 S10 with 4L60E and 4.3 is the same as the 94-95 V8 C/K trucks and if you get the TBI 4.3 V6 harness it should reduce the amount of rewiring necessary. You'll need a V8 chip (called a memcal) and you will need to find or build a calibration to burn onto the chip because the stock 5.7 TBI calibration is not correct for the L31 engine with TBI.

Yeah the more I read about the CSFI the more it seems like people are not very fond of it.

What all would I need for the TBI Conversion? New Intake, fuel pump, 4.3 TBI v6 harness, memcal?

[bybyc5]

The vortec heads require a vortec intake. Bolt pattern, port size and placement are a bit off from the older 350 motors. Limiting a retro intake swap/conversion from an older TBI motor. Unless you were to use the older heads, which don't perform like the vortec's.

Also, what about an inline booster pump, using the stock in tank pump for as a lift pump? I think you can get a 255L walbro inline kit for about $100 or so. I used this on my TPI system for my K1500. Works great.

[Boulky12]

Also, what about an inline booster pump, using the stock in tank pump for as a lift pump? I think you can get a 255L walbro inline kit for about $100 or so. I used this on my TPI system for my K1500. Works great.

So your saying that theirs pumps that help fuel pumps boost pressure?

[1project2many]

I've used a pump from a 90's Ford truck with 460 and PFI as an inline booster in the Vortec vans before. It extended the time between in tank pump replacements.

[bybyc5]

Yes. My truck came stock with a 350 TBI and it barely gave me 22 psi maxed out. My TPI system needed at least 39 lbs.
I believe this is the one I bought a couple years ago, although the price went up a few dollars.

http://www.amazon.com/Walbro-GSL-392...it+walbro+255L

But it works perfectly well inline as a booster pump with my low pressure TBI in tank pump. I used quality high pressure fuel line designed for fuel injection systems and spliced it into my fuel rail feed line. Wired it to it's own fuse protected circuit with a relay triggered by the existing stock fuel pump relay circuit.

[Nasty-Z]

I may be in the minority here , but as I read this I ask , why reinvent the wheel here ? The pump is in the tank for a reason , there are drop in replacements for it , just like the one I linked in one of my earlier posts .

I simply do not see why one would not simply swap the factory in tank pump for a hi flow aftermarket version , simple to do and eliminates all of the additional wiring / plumbing by adding inline "booster" pumps or whatever they can be called.

If cost is a factor or the reason not to do the 255 LPH Walbro , the E3270 Airtex will support semi mild combos , has 225 + LPH flow rate and is under $75 at most parts stores.

TOM

[PJG1173]

Dang well since I can't use the stock pump will the CSFI pump from the Full Size(donor) fit in the S10 Gas Tank?

Will the 4L80-E still be an issue even if I have the Harness and Computer from donor?

Thank you guys so much for the info.

Yes if you take the pump out of the newer sending unit it will fit in the s10 sending unit no problems. I used the pump out of a 2000 suburban in my 93 s10. If you are going to stick with the TBI changing the pump is ONLY a precaution and not necessarily a requirement. I only changed mine because it could not push the 20 psi I was trying to get out of it where the stock vortec pump would. I just recently purchased an aftermarket pump that is supposed to operate 15~100psi because I switched to MPFI and needed the additional pressure.
when I swapped a 97 suburban csfi 350 into my Toyota using TBI I used one of these intakes:
http://www.ebay.com/sch/i.html?_from...vortec&_sop=15
I specifically used this on since I am a fan of Air Gap intakes.
http://www.ebay.com/itm/Professional...24f42f&vxp=mtr
then I used one of these to adapt a 454 TB
http://www.jegs.com/i/Holley/510/17-...FdgIgQod5i0JRw

[Boulky12]

Yes if you take the pump out of the newer sending unit it will fit in the s10 sending unit no problems. I used the pump out of a 2000 suburban in my 93 s10. If you are going to stick with the TBI changing the pump is ONLY a precaution and not necessarily a requirement. I only changed mine because it could not push the 20 psi I was trying to get out of it where the stock vortec pump would. I just recently purchased an aftermarket pump that is supposed to operate 15~100psi because I switched to MPFI and needed the additional pressure.
when I swapped a 97 suburban csfi 350 into my Toyota using TBI I used one of these intakes:
http://www.ebay.com/sch/i.html?_from...vortec&_sop=15
I specifically used this on since I am a fan of Air Gap intakes.
http://www.ebay.com/itm/Professional...24f42f&vxp=mtr
then I used one of these to adapt a 454 TB
http://www.jegs.com/i/Holley/510/17-...FdgIgQod5i0JRw

Well I decided that I will use the CSFI system because I already have it. And I'll use the fuel pump from the truck it came in again, because I already have it. Motor was running good before I pulled it so maybe when it takes a shit I'll switch to TBI.

Thank you for answering that question. I would rather just swap in the Full Size pump because I don't have to spend more money. And I know it'll run at exactly the psi needed for the CSFI (bout 60-65 psi)

Thank you all for the great info.

[1project2many]

Yes if you take the pump out of the newer sending unit it will fit in the s10 sending unit no problems.

93 has old style pump. 95 Blazer CSFI even had old style pump. Good for 60 psi plus.